Scapula, AC Joint and Clavicle

Question 1

What are the projections of the clavicle?

Answer 1

AP
AP Axial
PA
PA Axial

Question 2

Clavicle - AP Projection

Answer 2

Upright or recumbent
CR - perpendicular
CP - middle of clavicle
Suspend on inspiration

Question 3

Why do you suspend on inspiration for an AP Clavicle Projection?

Answer 3

so that the clavicle is as high off the ribs as it can be

Question 4

Clavicle -AP Evaluation criteria

Answer 4

Entire clavicle visualized and centered
uniform density
lateral aspect above humerus
medial aspect superimposing the thorax

Question 5

Clavicle - AP Axial Projection

Answer 5

Upright or recumbent
CR - 15-30 degrees cephalad
- asthenic patients would require more angulature
Suspend on inspiration
secondary marker of up arrow signalling axial

Question 6

Clavicle - AP Axial Evaluation criteria

Answer 6

Entire clavicle visualized
majority of clavicle above scapula/ribs
medial end superimposing second rib
clavicle is more horizontal

Question 7

What are the benefits/downsides to performing PA clavicle projections? What would the CR angle be?

Answer 7

OID is smaller, less radiation to thyroid
more painful for patient
15-30 degrees caudad

Question 8

How do you image pedicatric clavicle?

Answer 8

supine for immobilization
bilateral for comparison

Question 9

AC Joint - AP projection

Answer 9

Upright in true AP
CP - MSP at level of AC joint
suspend on exhilation
Use both R and L markers (WW or weights)
Thyroid and gonadal sheilding
180cm SID
1 with and 1 without weights

Question 10

AC Joint- AP Evaluation criteria

Answer 10

both joints included, with and without weights
no rotation or leaning
if present, joint separation seen clearly on image with weights
no shrugging - arms relaxed down with weights

Question 11

AC Joint- AP Unilateral

Answer 11

4 images required
- with and without for each joint
- still give both weights
- maintain SID
- LPO or RPO depending on side
Thyroid collar not required
15X20cm FOV

Question 12

Scapula - AP Projection

Answer 12

Abduct arm to a right angle with body
Include all of scapula
Shallow breathing technique
- increase time, reduce mA

Question 13

Scapula - AP evaluation criteria

Answer 13

Lateral portion of scapula free from superimposition
Scapula slightly obliqued
No lung markings

Question 14

Scapula - Lateral (Y)

Answer 14

Oblique to align acromion and medial scapula (45-60 degrees) arm out of way
AP or PA oblique
- marker and shield correctly orriented
Suspend respiration

Question 15

Scapula - Lateral (Y) evaluation criteria

Answer 15

No superimposition of scapular body over bony thorax
No superimposition of humerus over scapula
Lateral scapula
humeral head and glenoid between coracoid and acromion