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1

What is a good "first line test" if you suspect pathology?

Radiograph

2

If an XR comes back negative, but you suspect fracture, what would be a good next step, and why?

CT: high spatial resolution, better for evaluating and characterizing bone

3

What imaging modality would be best for soft tissue injury, such as tendon or ligament pathology?

MRI: high contrast resolution

4

What imaging modality is best for finding abnormal edema?

MRI

5

MRI Standard Planes

axial, sagittal, coronal

6

MRI UE planes to optimize rotator cuff tears

coronal oblique (parallel to long axis of supraspinatus), sagittal oblique (perpendicular to long axis of supraspinatus), axial

7

XR standard view for long bones

2 views: AP and lateral (orthogonal planes)

8

XR standard view for joints

3 views: AP, lateral, oblique

9

XR standard view for shoulder

Trauma series: AP, Y-scapular (oblique), axillary
Nontrauma series: AP views in ER and IR

10

XR standard view for pelvis and hips

AP and frog leg lateral view

11

8 steps for how to read an X-ray

1. Identify normal bones (what lives there?)
2. Look for cortical continuity
3. Look at alignment
4. Look for any extra densities or lucencies within or outside bone
5. Look at soft tissues (swelling, effusion)
6. Look at adjacent joints
7. Compare with prior studies, if any
8. If there is still clinical concern for pathology, order CT or MRI

12

Wrist: Describe 3 arcs used to view X-ray

Arc I: proximal articular surface of scaphoid, lunate, triquetrum
Arc II: distal articular surface of scaphoid, lunate, triquetrum
Arc III: proximal articular surface of capitate and hamate
If there is no arc: dislocation

13

Wrist lateral view: what 4 structures should line up?

Radius, lunate, capitate, 3rd metacarpal

14

How to identify a fracture on an X-ray: 6 signs

1. cortical discontinuity or deformity
2. radiolucent fracture lines
3. abnormally white or dense areas, representing overlapping bony fragments or impaction of bone
4. extra or unexplained bony fragments
5. soft tissue swelling or joint effusion
6. callus formation in healing fractures (look fuzzy)

15

Gamekeeper's Thumb

disruption of ulnar collateral ligament of first MCP joint, may be avulsion fracture of proximal phalanx at UCL

16

Stener Lesion

Gamekeeper's thumb; displacement of UCL superficial to adductor pollicis aponeurosis; surgery required to heal avulsion fracture (adductor pollicis in the way)

17

Avascular necrosis of scaphoid: etiology

blood supply (from carpal branch of radial artery) to scaphoid bone begins distally and runs proximally, poor blood supply to proximal pole leads to AVN

18

If a patient has pain over the snuffbox of the wrist and X-ray is negative, what should be done?

if you have a high clinical suspicion of fracture, the wrist should be casted and pt. should get an MRI or repeat radiographs

19

posterior fat pad sign

abnormal radiolucency of posterior fat pad in elbow flexion; fat pad normally pressed into deep olecranon fossa by triceps tendon and anconeus (normally invisible on XR); visible when joint effusion present

20

give 1 pro and 1 con for the axillary view in a shoulder XP

Pro: better view than Y-scapular and more consistent
Con: can be a difficult/painful position for a person with a shoulder injury

21

Hill Sachs lesion: best view for XR

AP internal rotation

22

Hill Sachs lesion: what is it?

a cortical depression in the posterolateral head of the humerus, resulting from forceful impaction of the humeral head against the anteroinferior glenoid rim when the shoulder is dislocated anteriorly.

23

posterior shoulder dislocation: mechanism, etiology

humerus forced posteriorly in internal rotation; usually caused by convulsions, rarely by trauma

24

posterior shoulder dislocation: best imaging to diagnose, other pathology with similar presentation?

can "mimic" adhesive capsulitis; CT or MR best for viewing, often difficult to diagnose with XR

25

most common type of shoulder dislocation

anterior (95-97%)

26

posterior shoulder dislocation: what %?

2-4%

27

inferior (luxation) dislocation: what %?

0.5%

28

best imaging mode to view supraspinatus? best plane?

MRI (good for soft tissue); oblique coronal proton density or oblique sagittal fat sat proton density

29

Radiographic findings: chronic rotator cuff tears (3)

1. high riding humerus (<7mm acromiohumeral distance)
2. faceting and sclerosis in inferolateral acromion and superior aspect of greater tuberosity
3. secondary osteophytosis in GH joint to maintain joint congruity

30

clinical findings: rotator cuff tears (signs and symtpoms-5)

1. weak supraspinatus
2. weak GH external rotation
3. impingement
4. age >/= 60 (>60%)
5. night pain