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USG in normal menstrual cycle
The changes in the internal uterine lining of the uterus - the endometrium - during the menstrual cycle is termed the uterine cycle of menstruation
These changes occur in response to the hormones estrogen and progesterone secreted by the ovaries during the ovarian cycle of menstruatio -
Endometrial thickness is a commonly measured parameter on routine gynaecological ultrasound and MR imaging
The appearance as well as the thickness of the endometrium will depend on whether the patient is of reproductive age or post-menopausal and if of reproductive age at what point in the menstrual cycle they are examined
The endometrium should be measured in the long axis or sagittal plane
The measurement is of the thickest echogenic area from one basal endometrial interface across the endometrial canal to the other basal surface
Care should be taken not to include the hypoechoicmyometrium in this measurement
Premenopausal In premenopausal patients
there is significant variation at different stages of the menstrual cycle
during menstruation 2-4 mm early proliferative phase (day 6-
14) 4-8 mm late proliferative-pre ovulatory
phase up to 11 mm secretory phase 7-16 mm following dilatation and
curettage or spontaneous abortion lt5 mm if it is thicker consider retained products of conception
At birth the uterus is similar in size to the cervix (23ndash46 cm) and the endometrium generally appears as a thin echogenic line
Approximately one-fourth of neonates will have fluid collections within the endometrial cavity
Once puberty is reached the appearance of the endometriumbegins to approximate that seen in adulthood and varies with the stage of the menstrual cycle
Postmenopausal EM Will depend on the whether or
not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen
Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy
if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
The changes in the internal uterine lining of the uterus - the endometrium - during the menstrual cycle is termed the uterine cycle of menstruation
These changes occur in response to the hormones estrogen and progesterone secreted by the ovaries during the ovarian cycle of menstruatio -
Endometrial thickness is a commonly measured parameter on routine gynaecological ultrasound and MR imaging
The appearance as well as the thickness of the endometrium will depend on whether the patient is of reproductive age or post-menopausal and if of reproductive age at what point in the menstrual cycle they are examined
The endometrium should be measured in the long axis or sagittal plane
The measurement is of the thickest echogenic area from one basal endometrial interface across the endometrial canal to the other basal surface
Care should be taken not to include the hypoechoicmyometrium in this measurement
Premenopausal In premenopausal patients
there is significant variation at different stages of the menstrual cycle
during menstruation 2-4 mm early proliferative phase (day 6-
14) 4-8 mm late proliferative-pre ovulatory
phase up to 11 mm secretory phase 7-16 mm following dilatation and
curettage or spontaneous abortion lt5 mm if it is thicker consider retained products of conception
At birth the uterus is similar in size to the cervix (23ndash46 cm) and the endometrium generally appears as a thin echogenic line
Approximately one-fourth of neonates will have fluid collections within the endometrial cavity
Once puberty is reached the appearance of the endometriumbegins to approximate that seen in adulthood and varies with the stage of the menstrual cycle
Postmenopausal EM Will depend on the whether or
not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen
Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy
if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Endometrial thickness is a commonly measured parameter on routine gynaecological ultrasound and MR imaging
The appearance as well as the thickness of the endometrium will depend on whether the patient is of reproductive age or post-menopausal and if of reproductive age at what point in the menstrual cycle they are examined
The endometrium should be measured in the long axis or sagittal plane
The measurement is of the thickest echogenic area from one basal endometrial interface across the endometrial canal to the other basal surface
Care should be taken not to include the hypoechoicmyometrium in this measurement
Premenopausal In premenopausal patients
there is significant variation at different stages of the menstrual cycle
during menstruation 2-4 mm early proliferative phase (day 6-
14) 4-8 mm late proliferative-pre ovulatory
phase up to 11 mm secretory phase 7-16 mm following dilatation and
curettage or spontaneous abortion lt5 mm if it is thicker consider retained products of conception
At birth the uterus is similar in size to the cervix (23ndash46 cm) and the endometrium generally appears as a thin echogenic line
Approximately one-fourth of neonates will have fluid collections within the endometrial cavity
Once puberty is reached the appearance of the endometriumbegins to approximate that seen in adulthood and varies with the stage of the menstrual cycle
Postmenopausal EM Will depend on the whether or
not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen
Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy
if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
The endometrium should be measured in the long axis or sagittal plane
The measurement is of the thickest echogenic area from one basal endometrial interface across the endometrial canal to the other basal surface
Care should be taken not to include the hypoechoicmyometrium in this measurement
Premenopausal In premenopausal patients
there is significant variation at different stages of the menstrual cycle
during menstruation 2-4 mm early proliferative phase (day 6-
14) 4-8 mm late proliferative-pre ovulatory
phase up to 11 mm secretory phase 7-16 mm following dilatation and
curettage or spontaneous abortion lt5 mm if it is thicker consider retained products of conception
At birth the uterus is similar in size to the cervix (23ndash46 cm) and the endometrium generally appears as a thin echogenic line
Approximately one-fourth of neonates will have fluid collections within the endometrial cavity
Once puberty is reached the appearance of the endometriumbegins to approximate that seen in adulthood and varies with the stage of the menstrual cycle
Postmenopausal EM Will depend on the whether or
not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen
Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy
if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Premenopausal In premenopausal patients
there is significant variation at different stages of the menstrual cycle
during menstruation 2-4 mm early proliferative phase (day 6-
14) 4-8 mm late proliferative-pre ovulatory
phase up to 11 mm secretory phase 7-16 mm following dilatation and
curettage or spontaneous abortion lt5 mm if it is thicker consider retained products of conception
At birth the uterus is similar in size to the cervix (23ndash46 cm) and the endometrium generally appears as a thin echogenic line
Approximately one-fourth of neonates will have fluid collections within the endometrial cavity
Once puberty is reached the appearance of the endometriumbegins to approximate that seen in adulthood and varies with the stage of the menstrual cycle
Postmenopausal EM Will depend on the whether or
not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen
Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy
if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
At birth the uterus is similar in size to the cervix (23ndash46 cm) and the endometrium generally appears as a thin echogenic line
Approximately one-fourth of neonates will have fluid collections within the endometrial cavity
Once puberty is reached the appearance of the endometriumbegins to approximate that seen in adulthood and varies with the stage of the menstrual cycle
Postmenopausal EM Will depend on the whether or
not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen
Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy
if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Postmenopausal EM Will depend on the whether or
not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen
Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy
if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used
The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent
A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)
At this time the endometrium is disorganized and chaotic and only about 1mm thick
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer
There is thorough transmission and posterior acoustic enhancement noted
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding
And thus starts the next menstrual cycle
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment
Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant
This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate
This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation
One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Ovulation is determined by
following sonographic signs follicle suddenly disappears
or regresses in size irregular margins intra-follicular echoes Follicle
suddenly becomes more echogenic
free fluid in the pouch of Douglas
increased perifollicular blood flow velocities on doppler
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
At ovulation the follicle ruptures expelling the ovum into the fallopian tube
The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes
The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised
if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks
not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy
Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture
Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66
Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for
some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen
Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception
Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation
Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Failure of ovulation and development of ldquocysticrdquo follicle
The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure
Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst
No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity
The follicular fluid remains clearhypoechoic
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture
This results in retention of the oocytecumulus complex is within the lumen of the LUF
The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue
There is also a hazy indistinct border between the follicle fluid and the follicle wall
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH
In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent
Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation
Menstrual flow does occur but menses are often lighter than usual
The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH