Imaging the Musculoskeletal - PowerPoint Presentation

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Imaging the MusculoskeletalSystem The Extremities

Richard L.

Sulek

, D.O.Slide2

ObjectivesDiscuss:commonly used imaging modalities in the musculoskeletal systemnormal imaging anatomy in the extremities fracture descriptionSlide3

Imaging TechniquesPlain x-raysCT MRIUltrasoundNuclear Medicine (bone scan)Slide4

Plain x-rays

For joints like the ankle,

elbow or wrist we always

take 3 views:

AP, lateral and obliqueSlide5

3 views: AP, oblique and lateralSlide6

Advantages of plain x-raysQuickNot expensiveRelatively low radiationSlide7

Disadvantages of plain x-raysNot 3 dimensionalCan miss pathologyMay still require other imaging studiesSlide8

CT scannerSlide9

This is a CT scan: a longitudinal cross section

This CT shows a fracture through the medial cunieform

Great toeSlide10

Advantages of CT scanning of the musculoskeletal systemExcellent anatomic detailWill detect almost all pathology related to cortical bone injuryGreat for showing displacement or joint involvement

Now

multiplanarSlide11

Disadvantages of CTExpensive (x-ray $100, CT $1000)More radiationOften not necessarySlide12

MRI scanner

Looks more like a tunnel, must be very careful of metalSlide13

This is an MRI of the knee

There is no radiation used

Circled is a normal posterior cruciate ligamentSlide14

Advantages of MRINo radiationWe can slice through the body using any imaging planeLooks “inside” bone.

Marrow

evaluation.

MRI is very good for looking at the

soft tissues

(muscles, ligaments, tendons and cartilage)

MRI is very sensitive in detecting

waterSlide15

MRI shows water (fluid)

behind the patella

Do you see fluid

anywhere else?Slide16

Disadvantages of MRIVery expensive (x-ray $100, CT $1000,MRI $2000)Not as good as CT for cortical boneSlide17

This long black line

Is the cortex or cortical bone

3 things are always black

on MRI:

Air

Cortical bone/tendons/ligaments

Flowing bloodSlide18
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Posterior cruciate ligamentSlide20

anterior and posterior

horns “bow tie”Slide21
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Normal Imaging Anatomy in the ExtremitiesSlide26

What are the parts of a long bone?Terms you will need to know:CortexMedullary cavity (marrow)

Diaphysis

Metaphysis

Epiphysis

DMESlide27

cortex

Medullary cavity (marrow)

At each end of a long bone is the _________

The tapered part of the bone

is the __________

The shaft of the long

bone is the ________

Diaphysis

Metaphysis

EpiphysisSlide28

cortex

medullary cavitySlide29
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acromion

corocoid

glenoid fossa

clavicle

greater tuberosity

lesser tuberositySlide31
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Child or adult?Slide35

WristSlide36

1

2

3

4

Growth plate

Diaphysis

Metaphysis

EpiphysisSlide37
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SI joint

symphysis pubis

acetabulum

int. iliac spine

greater trochanterSlide39

intercondylar spines

Patella

Patella

condyle

fibulaSlide40

Ankle and FootSlide41
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lateral maleous

medial

maleolus

TalusSlide43
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2

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Test your knowledgeSlide45
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Finding a Fracture on X-RayStart with soft tissue, look for swelling or fat pad displacementExamine the cortex along the entire length of the boneLook for cortical irregularities, buckling, or evidence of impactionSlide47

Fracture TerminologyDirection of fracture line:TransverseObliqueSpiral

Longitudinal

Alignment

of fracture:

Displacement

Angulation

Comminution

Articular InvolvementSlide48

Fracture TerminolgyOpen vs Closed: fracture is open when exposed to air (laceration or gross exposure)Pathologic fracture: implies fracture through weakened bone

Stress fracture

: implies misuse or overuseSlide49

Path of the FractureSlide50

NormalSlide51

Transverse FractureSlide52

Oblique FractureSlide53

Spiral FractureSlide54

Longitudinal FractureSlide55

Simple vs ComminutedSimple-2 bone fragmentsComminuted-greater then 2 fragmentsSlide56

Avulsion FractureA bony fragment produced by the pull of ligamentous or tendinous attachmentSlide57

Torus FracturesAxial forces cause cortex to buckleOccurs most commonly in the metaphysisSlide58

Greenstick fractureCortex broken on one side of the bone and only bent or buckled on the other sideSlide59

Points to take homeThere are distinct advantages and disadvantages to plain x-rays, CT and MRI.Become familiar with terminology: epiphysis, metaphysis, diaphysis, cortex, medullary cavityFracture description requires specific vocabulary