Imaging

Question 1

What is a Hill Sach deformity and Bankart lesion?

Answer 1

Anterior dislocation of gleno-humeral joint
→ impact injury of humeral head (Hill Sach deformity) against glenoid fossa (Bankart lesion)

Question 2

What does a “light bulb” sign on a shoulder Xray indicate?

Answer 2

Posterior dislocation of glenohumeral joint

Question 3

What are 2 causes of abnormal bony protuberance?

Answer 3

1) Exostosis
2) Osteochondroma

Question 4

What is a possible physiological cause of a line of radiolucency within a adolescent’s bone on a radiograph.

Answer 4

Growth plate

Question 5

What is a possible of easy fractures that show abnormal radiolucency of underlying bone?

Answer 5

Pathological fracture with cancerous replacement of bone matrix/material

Question 6

What does a “fat pad” sign (presence of radiolucent shadows anterior and posterior to humerus) on an elbow xray indicate?

Answer 6

Elbow joint effusion

Question 7

What is a “nightstick” fracture?

Answer 7

Fracture to ulnar shaft

Question 8

What is a “Galeazzi fracture”.

Answer 8

Fracture @ distal 1/3 of radius
- a/w subluxation of distal radio-ulnar joint

Question 9

What is “Colle’s fracture”?

Answer 9

Fracture of distal radius with dorsal displacement of wrist and hand
- presents with “Dinner fork deformity” of forearm

Question 10

How does a scaphoid fracture lead to avascular necrosis?

Answer 10

Fracture → compression of radial artery → death of bone (avascular necrosis)
- chronic pain + l.o.f

Question 11

What is the most commonly torn ligament in a rotator cuff tear?

Answer 11

Supraspinatus

Question 12

How does a torn supraspinatus tendon differ from a normal one on ultrasound?

Answer 12

Normal tendon → hyperechoic

Tear → Fluid → Hypoechoic

Question 13

What is a “Terry Thomas” sign?

Answer 13

Widening of Scaphoid-Lunate gap → Scapholunate ligament injury

Question 14

What is an open mouth Xray used to assess?

Answer 14

C1 and 2 vertebrae

Question 15

What is an EOS?

Answer 15

Low-dose, weight bearing X-ray
- can take whole body frontal and lateral images
- less radiation than conventional xray
- can produce both 2D and 3D images
- poor demonstration of bony features

Question 16

What are 4 common imaging modalities used for back pain?

Answer 16

1) Radiograph
- good for 1st line

2) MRI
- good for soft tissue

3) CT
- goof for bony details

4) Nuclear medicine - bone scan
- good for bone metastasis

Question 17

How is a T1-weighted MRI sequence differentiated from a T2-weighted MRI sequence?

Answer 17

T1: fluid is dark
T2: fluid is white

Question 18

What is a bone scan?

Answer 18

Radioisotope injected IV → tracer incorporated into bone

• hot spots → ↑bone growth/repair
• cold spots → decreased/no uptake

Question 19

When is imaging indicated for a suspected cervical spine trauma?

Answer 19

N - Neurological deficit
S - Spinal tenderness
A - Altered mental status
I - Intoxication
D - Distracting injury

Question 20

How does one discern if there is an unstable injury after a suspected cervical spine injury?

Answer 20

All 4 lines of the neck vertebrae are straight/smooth.

1) Anterior vertebral
2) Posterior vertebral
3) Spinolaminar
4) Posterior spinous

Question 21

Which imaging modality is most suited for a suspected cervical spine trauma?

Answer 21

CT

Question 22

What are the 3 most common fractures of the thoracolumbar spine?

Answer 22

1) Compression
2) Burst
3) Chance

Question 23

What are 2 common degenerative conditions of the thoracolumbar spine?

Answer 23

1) Spondylosis
2) Disc disease