Imaging of Bone Marrow Imaging of Bone Marrow Jim Wu, MD Jim Wu, MD Beth Israel Deaconess Beth Israel Deaconess Medical Center (BIDMC) Medical Center (BIDMC) Harvard Medical School Harvard Medical School
Transcript
1. Imaging of Bone MarrowImaging of Bone Marrow Jim Wu, MDJim
Wu, MD Beth Israel Deaconess MedicalBeth Israel Deaconess Medical
Center (BIDMC)Center (BIDMC) Harvard Medical SchoolHarvard Medical
School
2. DisclosuresDisclosures Kaneka Corp - research funding
support Boehringer Ingelheim - research funding support PharmaMar -
imaging consultant
3. Learning ObjectivesLearning Objectives To learn the 2 types
of bone marrow andTo learn the 2 types of bone marrow and normal
conversion patternnormal conversion pattern To be able to
distinguish normal fromTo be able to distinguish normal from
abnormal bone marrow on MRIabnormal bone marrow on MRI Learn the
MRI imaging appearance ofLearn the MRI imaging appearance of
various bone marrow disordersvarious bone marrow disorders
4. Bone Marrow TypesBone Marrow Types Red (hematopoietic)Red
(hematopoietic) Present at birthPresent at birth 40% fatty40% fatty
40-50% hematopoietic cells40-50% hematopoietic cells Erythrocytes,
megakaryocytes,Erythrocytes, megakaryocytes,
granulocytesgranulocytes 10% structural elements10% structural
elements Increased in marrowIncreased in marrow proliferative
disordersproliferative disorders Islands of red marrow canIslands
of red marrow can remain in long bonesremain in long bones Yellow
(Fatty)Yellow (Fatty) Increases with ageIncreases with age 80%
fatty80% fatty 10% hematopoietic cells10% hematopoietic cells
Erythrocytes, megakaryocytes,Erythrocytes, megakaryocytes,
granulocytesgranulocytes 10% structural elements10% structural
elements Increased with marrowIncreased with marrow depletion
processesdepletion processes (radiation)(radiation)
5. Bone Marrow TypesBone Marrow Types Red (hematopoietic)Red
(hematopoietic) Yellow (Fatty)Yellow (Fatty)
6. Fatty Conversion of MarrowFatty Conversion of Marrow
Converts fromConverts from RedRed (hematopoietic) to(hematopoietic)
to YellowYellow (fatty)(fatty) Starts at hands and feet and
worksStarts at hands and feet and works centrallycentrally Distal
first, then proximalDistal first, then proximal Long bonesLong
bones Epiphysis and diaphysis firstEpiphysis and diaphysis first
Distal metaphysisDistal metaphysis Proximal metaphysisProximal
metaphysis Complete by age 24-26Complete by age 24-26
7. Fatty Conversion of MarrowFatty Conversion of Marrow Moore
et al. Radiology 1990; 175:219-223
8. Normal Marrow ConversionNormal Marrow Conversion 2 years 14
years 42 years T1 T1 T1 Courtesy of Dr. Mary Hochman, Boston
9. MarrowMarrow ReRe -- conversionconversion Response to
demandResponse to demand for hematopoiesisfor hematopoiesis Mature
fatty marrowMature fatty marrow replaced byreplaced by
hematopoietic marrowhematopoietic marrow Orderly sequenceOrderly
sequence Reverse pattern ofReverse pattern of marrow
conversionmarrow conversion
10. Marrow ReconversionMarrow Reconversion Obese femalesObese
females SmokersSmokers Hemolytic AnemiaHemolytic Anemia High
altitudeHigh altitude AthletesAthletes
Marrow-stimulatingMarrow-stimulating medications (e.g.
GCSF),medications (e.g. GCSF), erythropoietin (EPOerythropoietin
(EPO)) Replacement/destructionReplacement/destruction of normal
marrowof normal marrow GCSF Therapy
11. MRI Appearance of Red andMRI Appearance of Red and Yellow
MarrowYellow Marrow Red (hematopoietic)Red (hematopoietic) Slightly
hyperintense toSlightly hyperintense to muscle on T1muscle on T1
Hyperintense to fat on T2Hyperintense to fat on T2 Does not extend
past theDoes not extend past the physisphysis Signal drop out on
opposeSignal drop out on oppose phase T1 imagingphase T1 imaging
Yellow (Fatty)Yellow (Fatty) Hyperintense to muscle onHyperintense
to muscle on T1T1 Hypointense to muscle onHypointense to muscle on
STIRSTIR No signal drop out onNo signal drop out on oppose phase T1
imagingoppose phase T1 imaging
12. Hypointense Low Signal T1 STIR Hyperintense High Signal
Normal Marrow - Yellow (Fatty)Normal Marrow - Yellow (Fatty)
13. Normal Marrow Normal Marrow Hematopoietic
(Red)Hematopoietic (Red) Iso- or Slightly Hyperintense to Muscle
Hyperintense to Fat T1 STIR
14. Likely benign Likely pathologic ????? Compare lesion to
skeletal muscle on T1-weighted images Distinguishing Red Marrow
Versus Tumor 1. Hyperintense 2. Hypointense 3. Isointense
15. T1 T2 fat sat Normal Red MarrowNormal Red Marrow
16. Abnormal Marrow - Plasmacytoma T1 T2 fat sat Key Point:
Marrow should not be hypointense to normal skeletal muscle on
T1
18. Opposed-Phase MRIOpposed-Phase MRI Fat and water protons
precess at slightly different frequencies At 1.5 Tesla: Water Fat
Frequency (PPM) -3.5 PPM Opposed-phase: TE of ~2.3 ms In-phase: TE
of ~4.6 ms
19. Water Fat Water Fat In-phase Out-of-phase Opposed-Phase
MRI
20. In-phaseIn-phase Is this normal?? Out-of-phaseOut-of-phase
No drop out, so does not contains fatMarrow darker than skeletal
muscle B Cell Lymphoma
21. Is this normal??Is this normal?? In-phaseIn-phase
Out-of-phaseOut-of-phase
22. Red Marrow Stops at physisRed Marrow Stops at physis T1T2
fat sat
23. B Cell LymphomaB Cell Lymphoma T1 STIR
24. Normal VariationNormal Variation Red Marrow inRed Marrow in
SubchondralSubchondral EpiphysisEpiphysis
25. Spine: Compare Marrow toSpine: Compare Marrow to Normal
DiscNormal Disc Abnormal Marrow Hypo-intense Normal Marrow
Hyper-intense T1 T1 Red Marrow Marrow Infiltration
26. Additional MRI TechniquesAdditional MRI Techniques
Diffusion weighted imaging (DWI)Diffusion weighted imaging (DWI)
Malignancies have restricted diffusion (bright on ADCMalignancies
have restricted diffusion (bright on ADC images)images) Helpful in
distinguishing benign from malignantHelpful in distinguishing
benign from malignant vertebral body compression fracturevertebral
body compression fracture Dynamic contrast enhancement (DCE)Dynamic
contrast enhancement (DCE) Better than static gad pre and post
imagesBetter than static gad pre and post images Rates of
enhancement can distinguish benign fromRates of enhancement can
distinguish benign from malignant disorders depends on age and fat
contentmalignant disorders depends on age and fat content MR
spectroscopy (MRS)MR spectroscopy (MRS) Choline to lipid ratio may
help distinguish benign fromCholine to lipid ratio may help
distinguish benign from malignant bone marrow disordersmalignant
bone marrow disorders
28. Marrow Proliferative DisordersMarrow Proliferative
Disorders Overproduction of bone marrow elementsOverproduction of
bone marrow elements Diffuse low signal on T1, variable on
T2Diffuse low signal on T1, variable on T2 DiseasesDiseases
myelofibrosismyelofibrosis polycythemia verapolycythemia vera
myelodysplastic syndromemyelodysplastic syndrome leukemialeukemia
multiple myelomamultiple myeloma amyloidosisamyloidosis
31. Marrow Proliferative DisordersMarrow Proliferative
Disorders Different from disorders that lead to
reconversionDifferent from disorders that lead to reconversion to
red marrowto red marrow AnemiasAnemias SmokingSmoking
HypoxiaHypoxia Chronic heart diseaseChronic heart disease Endurance
athletesEndurance athletes G-CSF or erythropoietin (EPO)G-CSF or
erythropoietin (EPO) Biopsy of reconversion disorders will yield
normalBiopsy of reconversion disorders will yield normal red marrow
whereas marrow proliferativered marrow whereas marrow proliferative
disorders will be abnormaldisorders will be abnormal
32. Marrow Replacement DisordersMarrow Replacement Disorders
Infiltration of cells thatInfiltration of cells that do not
belongdo not belong inin bone marrowbone marrow Typically focal or
multifocal, NOT diffuseTypically focal or multifocal, NOT diffuse
DiseasesDiseases METASTASESMETASTASES bone tumorsbone tumors
osteomyelitisosteomyelitis lymphomalymphoma GauchersGauchers
33. Marrow Replacement DisordersMarrow Replacement Disorders
Breast CA metastases Osteomyelitis
34. Which side is abnormal ??Which side is abnormal ?? B Cell
Lymphoma T1
35. Marrow DepletionMarrow Depletion Ablation or failure of
redAblation or failure of red marrow elementsmarrow elements Looks
like Fat!Looks like Fat! T1: like fatT1: like fat T2: like fatT2:
like fat Distribution: diffuse orDistribution: diffuse or
regionalregional Diseases:Diseases: Aplastic anemiaAplastic anemia
Radiation therapyRadiation therapy ChemotherapyChemotherapy Post
Radiation
36. Marrow EdemaMarrow Edema Generic term for high signal on
fluid sensitiveGeneric term for high signal on fluid sensitive
sequencessequences Bone marrow edema due to hyperemia or
ischemiaBone marrow edema due to hyperemia or ischemia T1:
hypointenseT1: hypointense T2: high signal (marrow edema
pattern)T2: high signal (marrow edema pattern) Distribution: focal,
often at epiphysisDistribution: focal, often at epiphysis
DiseasesDiseases trauma acute, chronic (osteoarthritis)trauma
acute, chronic (osteoarthritis) infectioninfection
osteonecrosisosteonecrosis transient edema, regional migratory
edematransient edema, regional migratory edema inflammatory
arthritisinflammatory arthritis
39. Distribution Diffuse (Proliferative, Infiltrative) Focal
Multifocal
40. Distribution - Diffuse Often symmetricOften symmetric
Marrow reconversionMarrow reconversion Marrow proliferativeMarrow
proliferative diseasesdiseases Multiple myelomaMultiple myeloma
LeukemiaLeukemia Polycythemia veraPolycythemia vera
MyelofibrosisMyelofibrosis Polycythemia Vera
41. Distribution - Focal TumorTumor TraumaTrauma
OsteonecrosisOsteonecrosis Transient edemaTransient edema
InfectionInfection InflammationInflammation
DegenerativeDegenerative RadiationRadiation Islands of red
marrowIslands of red marrow T1 STIR Staph
Discitis/Osteomyelitis
43. SummarySummary Two types of bone marrow and predictableTwo
types of bone marrow and predictable conversion patternconversion
pattern [1] Red (hematopoietic) & [2] yellow (marrow)[1] Red
(hematopoietic) & [2] yellow (marrow) Fatty conversion -
Appendicular to AxialFatty conversion - Appendicular to Axial
Epiphysis diaphysis distal metaphysisEpiphysis diaphysis distal
metaphysis MRI appearance of normal and abnormal boneMRI appearance
of normal and abnormal bone marrowmarrow Hyperintense on T1 when
compared to muscle and discHyperintense on T1 when compared to
muscle and disc Stops at physis or physeal scarStops at physis or
physeal scar In and out of phase imaging red marrow drops outIn and
out of phase imaging red marrow drops out