Date post: | 03-Jan-2016 |
Category: |
Documents |
Upload: | kristin-lyons |
View: | 219 times |
Download: | 0 times |
1
Ultrasound Ultrasound Evaluation of Evaluation of the Neonatethe Neonate
SpineSpineHarry H. Holdorf Harry H. Holdorf
IndicationsIndications
Ultrasound of the neonate spine can Ultrasound of the neonate spine can be an accurate, fast, and cost-be an accurate, fast, and cost-effective alternative to MRI imaging.effective alternative to MRI imaging.
Evaluations include:Evaluations include: Congenital or acquired abnormalities of Congenital or acquired abnormalities of
the neonate or young infant spinal the neonate or young infant spinal canal.canal.
2
The Neonatal SpineThe Neonatal Spine
EmbryologyEmbryology AnatomyAnatomy FunctionFunction IndicationsIndications Sonographic TechniqueSonographic Technique Sonographic AppearanceSonographic Appearance PathologyPathology
EmbryologyEmbryology
Neural plate - a thickened piece of Neural plate - a thickened piece of ectoderm that becomes the neural ectoderm that becomes the neural tube tube
Spinal meninges - membranes that Spinal meninges - membranes that cover the nervous system; dura, cover the nervous system; dura, arachnoid, pia materarachnoid, pia mater
Paraxial mesoderm - tissue that Paraxial mesoderm - tissue that forms on the lateral aspect of neural forms on the lateral aspect of neural tube that eventually form the tube that eventually form the vertebral columnvertebral column 4
Embryology Embryology Primary Neurulation – process by Primary Neurulation – process by
which the ectoderm becomes the which the ectoderm becomes the neural tube; forms cervical through neural tube; forms cervical through second sacral segment; occurs second sacral segment; occurs between day 18 to 28 of gestationbetween day 18 to 28 of gestation ectoderm...neural plate...neural ectoderm...neural plate...neural
folds...neural tube (Medscape)folds...neural tube (Medscape) Disjunction – process by which Disjunction – process by which
neuroectoderm separates from neuroectoderm separates from cutaneous ectodermcutaneous ectoderm
Embryology – Primary Embryology – Primary NeurulationNeurulation
Embryology – Primary Embryology – Primary NeurulationNeurulation
EmbryologyEmbryology Secondary Neurulation – process that Secondary Neurulation – process that
forms the conus medularis, cauda forms the conus medularis, cauda equina and filum terminale distal to S2 equina and filum terminale distal to S2 levellevel Canalization - Distal neural tube forms from the Canalization - Distal neural tube forms from the
caudal cell mass; undifferentiated cells...caudal caudal cell mass; undifferentiated cells...caudal cell mass...neural tube. cell mass...neural tube. the ventriculus terminalis forms at the terminal end of the neural tube near the coccyx, marking the site of the future conus medularis.
Retrogressive differentiation - tissue caudal to Retrogressive differentiation - tissue caudal to ventriculus terminalis forms the filum terminalle, ventriculus terminalis forms the filum terminalle, cauda equina and the ascention of the conus cauda equina and the ascention of the conus (Medscape)(Medscape)
8
Embryology – Secondary Embryology – Secondary NeurulationNeurulation
http://php.med.unsw.edu.au/http://php.med.unsw.edu.au/embryology/index.php?embryology/index.php?title=Development_Animation_-title=Development_Animation_-_Secondary_Neurulation_Secondary_Neurulation
Embryology – Secondary Embryology – Secondary NeurulationNeurulation
Anatomy -VertebraeAnatomy -Vertebrae
Vertebrae - Cervical, thoracic, lumbarVertebrae - Cervical, thoracic, lumbarSacrum – consists of 5 fused vertebraeSacrum – consists of 5 fused vertebraeCoccyx – 3 or 4 fused vertebraeCoccyx – 3 or 4 fused vertebrae
VertebraeVertebraeC7 - T12 -L5 - S5C7 - T12 -L5 - S5
SacrumSacrum
Anatomy – Spinal CordAnatomy – Spinal Cord
Spinal cord – extends from medulla Spinal cord – extends from medulla oblongata and terminates at the filum oblongata and terminates at the filum terminaleterminale Conus medularis – inferior end of cord Conus medularis – inferior end of cord
that tapers into a V shape; the tip should that tapers into a V shape; the tip should be lie at the L2-L3 interspace or abovebe lie at the L2-L3 interspace or above
Filum terminale – cordlike extension of Filum terminale – cordlike extension of the conus medularis; should be less than the conus medularis; should be less than 2 mm in diameter2 mm in diameter
Cauda Equina – group of nerve fibers that Cauda Equina – group of nerve fibers that extend from the tip of the conus extend from the tip of the conus medularismedularis
AnatomyAnatomy
FunctionFunction
Spinal column protects the spinal Spinal column protects the spinal cord and nervescord and nerves
Provides support for body in upright Provides support for body in upright positionposition
Provides balance and weight Provides balance and weight distributiondistribution
Provide base to which ribs can Provide base to which ribs can attachattach
Nerves with cord carry impulses Nerves with cord carry impulses to/from brainto/from brain
Why Sonography?Why Sonography?
Can be done on infants less than 6 Can be done on infants less than 6 months oldmonths old
Posterior spinous processes have not Posterior spinous processes have not ossified ossified
InexpensiveInexpensive No radiationNo radiation Allows real-time visualization of cord Allows real-time visualization of cord
movementmovement No sedationNo sedation Can be performed almost anywhereCan be performed almost anywhere17
Indications Indications (JRC-DMS)(JRC-DMS)
Sacral dimple (most common reason US Sacral dimple (most common reason US ordered)ordered)
HemangiomaHemangioma Raised midlineRaised midline Hairy patchHairy patch Tail-like projection of lower spineTail-like projection of lower spine Dx of myelomeningocele or myeloschisisDx of myelomeningocele or myeloschisis Lower extremity deformitiesLower extremity deformities
Sonographic TechniqueSonographic Technique
Transducer - Highest frequency Transducer - Highest frequency linear that enables visualization of linear that enables visualization of anatomyanatomy Cervical spine use curvilinear txCervical spine use curvilinear tx
Select appropriate system presetsSelect appropriate system presets Patient PositionsPatient Positions
ProneProne DecubitusDecubitus Upright Upright (JCR-DMS)(JCR-DMS)
Scan entire back in long and Scan entire back in long and transversetransverse
Sonographic Technique Sonographic Technique (AIUM)(AIUM)
Determine level of conus medullarisDetermine level of conus medullaris Determine L5, then count cephaladDetermine L5, then count cephalad Determine S1, then count cephalad (1Determine S1, then count cephalad (1stst
coccygeal segment is more rounded, coccygeal segment is more rounded, sacral more squared)sacral more squared)
Last rib bearing vertebra is T12, then Last rib bearing vertebra is T12, then count caudalcount caudal
Skin marker at location of conus can be Skin marker at location of conus can be correlated with radiographcorrelated with radiograph
Sonographic Appearance Sonographic Appearance (Rumack)(Rumack)
Spinal Cord is hypoechoic; size and shape vary Spinal Cord is hypoechoic; size and shape vary with locationwith location Cervical – ovalCervical – oval Thoracic – circularThoracic – circular Thoracolumbar - thickerThoracolumbar - thicker
Central Echo complex – echogenic line within the Central Echo complex – echogenic line within the cord; may see fluid within (see Rumack)cord; may see fluid within (see Rumack)
Filum Terminale – Center is relatively Filum Terminale – Center is relatively hypoechoic with bright outer margins (see hypoechoic with bright outer margins (see Rumack); may not be distinguishable from nerve Rumack); may not be distinguishable from nerve fibers fibers
Sonographic AppearanceSonographic Appearance
Nerve root interfaces are echogenicNerve root interfaces are echogenic Filar Cyst – Cystic structure at the tip Filar Cyst – Cystic structure at the tip
of the conus medullaris at origin of of the conus medullaris at origin of filum terminale filum terminale Also referred to as terminal ventricleAlso referred to as terminal ventricle Causes no clinical symptomsCauses no clinical symptoms
Under normal conditions, the spinal Under normal conditions, the spinal cord should float freely within CSFcord should float freely within CSF
Will move with breathing and Will move with breathing and pulsations from vasculaturepulsations from vasculature
Normal Neonatal SpineNormal Neonatal Spine
Normal Neonatal SpineNormal Neonatal Spine
Conus medularisConus medularis
Transverse lumbar sonogram shows Transverse lumbar sonogram shows normal anatomy as labeled. V = normal anatomy as labeled. V =
vertebra, transverse process vertebra, transverse process
((arrowheadarrowhead).).
Pathology – Tethered Pathology – Tethered Cord (Westbrook)Cord (Westbrook)
Fixation of the spinal cord in an Fixation of the spinal cord in an abnormal locationabnormal location
Conus medullaris positioned below Conus medullaris positioned below the level of L3the level of L3
Can be due to a thickened filum Can be due to a thickened filum terminale (greater than 2 mm) or a terminale (greater than 2 mm) or a meningomyelocelemeningomyelocele
Can be associated with a lipoma, Can be associated with a lipoma, dermal sinus diastematomyeliadermal sinus diastematomyelia
Limited cord motionLimited cord motion
Pathology – Tethered Pathology – Tethered CordCord
Can be associated with other Can be associated with other anomalies, i.e. spinal bifida, anomalies, i.e. spinal bifida, anorectal malformations, etc.anorectal malformations, etc.
May not be discovered until later in May not be discovered until later in life when growth may strain cord life when growth may strain cord and cause symptomsand cause symptoms Weakness in musclesWeakness in muscles ScoliosisScoliosis Changes in bladder functionChanges in bladder function Sensory lossSensory loss
29
PathologyPathology Spinal Dysraphism – general term Spinal Dysraphism – general term
for congenital disorders that involve for congenital disorders that involve incomplete fusion of mesenchymal, incomplete fusion of mesenchymal, bone and neural elements of the bone and neural elements of the spine (Westbrook).spine (Westbrook). Overt – Open or uncovered lesions due Overt – Open or uncovered lesions due
to incomplete closure of posterior bony to incomplete closure of posterior bony elements of spineelements of spine
Occult – spinal anomalies that occur Occult – spinal anomalies that occur beneath intact skinbeneath intact skin
PathologyPathology In In occult spinal dysraphism,occult spinal dysraphism, ≥ 1 vertebrae do not form ≥ 1 vertebrae do not form
normally, and the spinal cord and meninges may also be normally, and the spinal cord and meninges may also be affected. In affected. In spina bifida cystica,spina bifida cystica, the protruding sac can the protruding sac can contain meninges (meningocele), spinal cord (myelocele), or contain meninges (meningocele), spinal cord (myelocele), or both (meningomyelocele). both (meningomyelocele).
Overt Lesions - Overt Lesions - MyeloceleMyelocele
Cyst-like spinal lesion that exposes the Cyst-like spinal lesion that exposes the neural placode (spinal cord) to the neural placode (spinal cord) to the environmentenvironment
Spinal cord is flush with the plane of the Spinal cord is flush with the plane of the dorsal skin. See Rumack.dorsal skin. See Rumack.
Not covered with meninges or skinNot covered with meninges or skin Usually at lumbosacral levelUsually at lumbosacral level Always associated with tethering of the Always associated with tethering of the
spinal cord (Unsinn). spinal cord (Unsinn). Chiari II syndrome occurs in 99% of Chiari II syndrome occurs in 99% of
patients with myelocele or patients with myelocele or myelomeningocele (Unsinn).myelomeningocele (Unsinn).
32
Overt Lesions - Overt Lesions - MyelomeningoceleMyelomeningocele
Low termination of cord with Low termination of cord with herniation of neural elements (CSF and herniation of neural elements (CSF and nerves) beyond bony defect and nerves) beyond bony defect and through the skinthrough the skin
Cord tethering is almost always Cord tethering is almost always involved (Westbrook).involved (Westbrook).
Almost always associated with Chiari II Almost always associated with Chiari II malformation malformation
Sonographic Findings - differentiate Sonographic Findings - differentiate from meningocele; detect associated from meningocele; detect associated anomalies (hydromelia, lipoma, etc.)anomalies (hydromelia, lipoma, etc.)
See Rumack.See Rumack.
PathologyPathologyOccult Spinal Occult Spinal DysraphismDysraphism
Spinal anomalies that occur beneath Spinal anomalies that occur beneath intact skinintact skin
Frequently there are visual indications Frequently there are visual indications that a problem existsthat a problem exists
Some examples of occult lesions areSome examples of occult lesions are Spinal lipomaSpinal lipoma MeningoceleMeningocele MyelocystoceleMyelocystocele DiastematomyeliaDiastematomyelia HydromyeliaHydromyelia Dorsal Dermal Sinus Dorsal Dermal Sinus
Spinal LipomaSpinal Lipoma
Fatty mass that extends into the spinal Fatty mass that extends into the spinal canal and can extend into subcutaneous canal and can extend into subcutaneous tissue.tissue.
Usually located at the level of the conus Usually located at the level of the conus or filum terminaleor filum terminale
Can be associated with tethered cordCan be associated with tethered cord Can be difficult to differentiate from Can be difficult to differentiate from
teratoma; use location of lesion to teratoma; use location of lesion to differentiate differentiate
Sonographical findings: echogenic massSonographical findings: echogenic mass See Rumack.See Rumack.
Spinal LipomaSpinal Lipoma
Meningocele (Rumack)Meningocele (Rumack)
Cystic herniation of CSF and Cystic herniation of CSF and meningesmeninges
Neural elements not involved; cord Neural elements not involved; cord usually develops normallyusually develops normally
UncommonUncommon
37
MeningoceleMeningocele
MyelocystoceleMyelocystocele
Malformation in which the dilated Malformation in which the dilated central canal of the spinal cord central canal of the spinal cord protrudes dorsally through a bony protrudes dorsally through a bony defect (Rumack)defect (Rumack)
Can occur in any region of spineCan occur in any region of spine Not usually associated with Chiari II Not usually associated with Chiari II
malformationmalformation
39
DiastamatomyeliaDiastamatomyelia
A sagittal division of the cord into A sagittal division of the cord into hemicords, each containing a hemicords, each containing a central canal and nerve roots central canal and nerve roots
About ½ of patients will present About ½ of patients will present with a surface stigmata of an with a surface stigmata of an underlying malformationunderlying malformation
Diagnosis sometimes delayed until Diagnosis sometimes delayed until child develops orthopedic and/or child develops orthopedic and/or neurologic symptoms neurologic symptoms
May occur alone or with other May occur alone or with other anomaliesanomalies
DiastamatomyeliaDiastamatomyelia
Hydromyelia (JRC)Hydromyelia (JRC)
Dilatation of the central canal which Dilatation of the central canal which may be diffuse or focalmay be diffuse or focal
Associated with myelomeningocele Associated with myelomeningocele and diastamotomyelia and diastamotomyelia
Sonographic findings: separation of Sonographic findings: separation of echogenic linear structures of the echogenic linear structures of the central canal central canal
HydromyeliaHydromyelia
Dorsal Dermal Sinus Dorsal Dermal Sinus (Rumack)(Rumack)
Fluid tract extending from skin that may Fluid tract extending from skin that may or may not penetrate the duraor may not penetrate the dura
Results from incomplete disjunctionResults from incomplete disjunction Most often seen in the lumbosacral areaMost often seen in the lumbosacral area Skin opening usually is located cephalad Skin opening usually is located cephalad
to the sinus connection with the durato the sinus connection with the dura Can be attached to cord and cause Can be attached to cord and cause
tetheringtethering See Rumack.See Rumack.
45
Dorsal Dermal SinusDorsal Dermal Sinus
Dorsal Dermal SinusDorsal Dermal Sinus
ReferencesReferencesACR-AIUM Practice Guidelines for the Performance of an Ultrasound Examination of the Neontal Spine; October, ACR-AIUM Practice Guidelines for the Performance of an Ultrasound Examination of the Neontal Spine; October, 2007.2007.
Images on slides 22-25 were obtained from The pediatric spinal canal.ppt. Original author unknown.Images on slides 22-25 were obtained from The pediatric spinal canal.ppt. Original author unknown.
Image Slide 5 from http://www.ncbi.nlm.nih.gov/books/NBK10080/figure/A2873/?report=objectonly retrived on Image Slide 5 from http://www.ncbi.nlm.nih.gov/books/NBK10080/figure/A2873/?report=objectonly retrived on Sept 12, 2012Sept 12, 2012
Image Slide 6 from http://www.ncbi.nlm.nih.gov/books/NBK10080/figure/A2879/?report=objectonly; retrieved on Image Slide 6 from http://www.ncbi.nlm.nih.gov/books/NBK10080/figure/A2879/?report=objectonly; retrieved on Sept. 12, 2012Sept. 12, 2012Image Slide 8 http://php.med.unsw.edu.au/embryology/index.php?title=Development_Animation_-Image Slide 8 http://php.med.unsw.edu.au/embryology/index.php?title=Development_Animation_-_Secondary_Neurulation_Secondary_NeurulationImage Slide 9 http://www.radsource.us/clinic/0807Image Slide 9 http://www.radsource.us/clinic/0807Image Slide 14 http://www.childrensmercy.org/content/view.aspx?id=6196Image Slide 14 http://www.childrensmercy.org/content/view.aspx?id=6196Image Slide 30 – Meningelocele, myelocel, Image Slide 30 – Meningelocele, myelocel, http://www.merckmanuals.com/professional/pediatrics/congenital_neurologic_anomalies/spina_bifida.htmlhttp://www.merckmanuals.com/professional/pediatrics/congenital_neurologic_anomalies/spina_bifida.htmlImage Slide 40 –Diastamatomyelia http://www.jultrasoundmed.org/content/29/9/1357/F2.expansion?ck=nckImage Slide 40 –Diastamatomyelia http://www.jultrasoundmed.org/content/29/9/1357/F2.expansion?ck=nckImage Slide 42 – Hydromyelia -http://www.ultrasoundcases.info/Slide-View.aspx?cat=507&case=2168Image Slide 42 – Hydromyelia -http://www.ultrasoundcases.info/Slide-View.aspx?cat=507&case=2168Image Slide 41 – Dorsal Dermal Sinus http://www.minnisjournals.com.au/ajum/article/Ultrasound-examination-of-Image Slide 41 – Dorsal Dermal Sinus http://www.minnisjournals.com.au/ajum/article/Ultrasound-examination-of-the-neonatal-spine-24 Tethered Cord Syndrome: a review of the literature: embryology. Medscape News Today; the-neonatal-spine-24 Tethered Cord Syndrome: a review of the literature: embryology. Medscape News Today; retrieved on May 30, 2011 from retrieved on May 30, 2011 from http://www.medscape.com/viewarticle/725080_2http://www.medscape.com/viewarticle/725080_2 Image slide 44 - http://www.ultrasoundcases.info/Slide-View.aspx?cat=507&case=4224Image slide 44 - http://www.ultrasoundcases.info/Slide-View.aspx?cat=507&case=4224Images Slide 45 - http://www.ultrasoundcases.info/Slide-View.aspx?cat=507&case=4224Images Slide 45 - http://www.ultrasoundcases.info/Slide-View.aspx?cat=507&case=4224
Unsinn, K., Geley T., Freund, M & Gassner, I. US of the Spinal Cord in Newborns: Spectrum of normal findings, Unsinn, K., Geley T., Freund, M & Gassner, I. US of the Spinal Cord in Newborns: Spectrum of normal findings, variants, congenital anomalies, and acquired diseasesvariants, congenital anomalies, and acquired diseases
Westbrook, C., Rouse, G. and DeLange, M. Sonographic evaluation of the Spine in infants and neonates. Westbrook, C., Rouse, G. and DeLange, M. Sonographic evaluation of the Spine in infants and neonates. Journal of Journal of Diagnostic Medical SonographyDiagnostic Medical Sonography 7:325-331, 325-331. 7:325-331, 325-331.
47