DR Topic 5: Humerus & Shoulder imaging

Question 1

Exposure factors and rationale for humerus (smaller patient)

Answer 1

60kVp

• High contrast image (large attenuation diff between adjacent anatomical structures
• Low beam penetration as small/thin anatomical area

100mA

• Require fine focus for image detail
• Doesn’t need exceptionally short exposure time as minimal movement risk

0.05s

• 5 mAs provides appropriate image density

No grid

• Small anatomical area = minimal scatter radiation

Question 2

Exposure factors and rationale for humerus (larger patient)

Answer 2

65kVp

• High contrast image (large attenuation diff between adjacent anatomical structures
• Higher beam penetration as thicker anatomical area

200mA

• Require fine focus for image detail
• Increase mA due to possible movement artefact

0.05s

• 10 mAs provides appropriate image density

Yes grid

• Larger anatomical area = more scatter radiation

Question 3

Exposure factors and rationale for shoulder AP/clavicle

Answer 3

65kVp

• High contrast image (large attenuation diff between adjacent anatomical structures
• Higher beam penetration as thicker anatomical area

200mA

• Require fine focus for image detail
• Increase mA due to possible movement artefact

0.07s

• 14 mAs provides appropriate image density

Yes grid

• Larger anatomical area = more scatter radiation

Question 4

Exposure factors and rationale for shoulder lateral

Answer 4

77kVp

• High contrast image (large attenuation diff between adjacent anatomical structures
• Higher beam penetration as thicker anatomical area

200mA

• Require fine focus for image detail
• Increase mA due to possible movement artefact

0.08s

• 16 mAs provides appropriate image density

Yes grid

• Larger anatomical area = more scatter radiation

Question 5

Exposure factors and rationale for shoulder oblique

Answer 5

65kVp

• High contrast image (large attenuation diff between adjacent anatomical structures
• Low beam penetration as small/thin anatomical area

100mA

• Require fine focus for image detail
• Doesn’t need exceptionally short exposure time as minimal movement risk

0.06s

• 6 mAs provides appropriate image density

No grid

• Small anatomical area = minimal scatter radiation

Question 6

Exposure factors and rationale for shoulder inferosuperior

Answer 6

70kVp

• High contrast image (large attenuation diff between adjacent anatomical structures
• Low beam penetration as small/thin anatomical area

200mA

• Require fine focus for image detail
• Increase mA due to risk of movement artefact

0.05s

• 10 mAs provides appropriate image density

No grid

• Small anatomical area = minimal scatter radiation

Question 7

Humerus & Shoulder projections

Answer 7

• AP humerus
• Lateral humerus
• AP shoulder (erect)
• AP shoulder (supine, trauma)
• Gleno-humeral joint view (Grashey view)
• Gleno-humeral joint with internal rotation
• Gleno-humeral joint with external rotation
• Superoinferior (SI) axial shoulder
• Inferosuperior (IS) axial shoulder
• Y-view/true lateral shoulder
• PA clavicle
• AP clavicle
• IS clavicle
• AP scapula
• Lateral scapula
• Acromioclavicular joints (ACJs)
• Transthoracic lateral

Question 8

AP humerus imaging technique

Answer 8

• Patient standing facing x-ray tube, affected arm extended and abducted
• Centre in middle of humerus
• Collimate shoulder joint, humerus, elbow joint, soft tissue

Question 9

Lateral humerus imaging technique

Answer 9

• Patient standing facing IR, affected arm extend and abducted
• Centre in middle of humerus
• Collimate shoulder joint, humerus, elbow joint, soft tissues

Question 10

AP shoulder (erect) imaging technique

Answer 10

• Posterior aspect of shoulder in contact with IR, arm fully extended, slightly abducted with palm facing forward, trunk rotated approx. 20 degrees
• Centre to centre of IR
• Collimate head and proximal third of humerus, scapula, clavicle, soft tissues

Question 11

Gleno-humeral joint view (Grashey view) imaging technique

Answer 11

• Patient back against IR, turned toward affected side 30-45 degrees, affected arm internally rotated
• Centre 2.5cm inferior to coracoid process, or 2cm inferior to lateral clavicle at level of glenohumeral joint
• Collimate proximal third of humerus, medial third of medial clavicle

Question 12

SI axial shoulder imaging technique

Answer 12

• Arm fully abducted, patient leans laterally over IR, hand internally rotated and pronated
• 5-15 degree tube angle
• Centre over middle of head of humerus
• Collimate head and proximal third of humerus, glenoid cavity, acromion, coracoid process, surrounding soft tissues

Question 13

IS axial shoulder imaging technique

Answer 13

• Patient supine, pad beneath shoulder, IR supported erect, tube side against head of humerus and in contact with neck, arm abducted to 90 degrees
• Centre through the axilla
• Collimate head and proximal third of humerus, glenoid cavity, acromion, coracoid process, surrounding soft tissues

Question 14

Y view/true lateral imaging technique

Answer 14

• Patient erect, facing IR, rotate 25 degrees to bring affected side closer to IR, arm on affected side adducted from trunk, elbow flexed, hand resting on side of waist
• Centre to upper end of medial border of scapula
• Collimate scapula, head and proximal third of humerus, surrounding soft tissues

Question 15

PA clavicle imaging technique

Answer 15

• Patient stands facing IR, arm made comfortable, rotate patient 15 degrees away from affected side
• Centre to centre of IR so central ray exits midshaft of clavicle
• Collimate clavicle, AC joint, sternoclavicular joint

Question 16

AP clavicle imaging technique

Answer 16

• Patient stands facing beam, arm made comfortable
• Centre over mid-point of clavicle
• Collimate clavicle, AC joint, SC joint

Question 17

IS clavicle imaging technique

Answer 17

• Same as AP clavicle
• Beam cranially angled 30-45 degrees
• Centre over mid-point of clavicle
• Collimate clavicle, AC joint, SC joint

Question 18

AP scapula imaging technique

Answer 18

• Same as AP shoulder, IR portrait instead of landscape
• No need to collimate medial end of clavicle/SC joint

Question 19

Lateral scapula imaging technique

Answer 19

• Identical to lateral shoulder

Question 20

Acromioclavicular joints imaging technique

Answer 20

• Patient facing beam, back on IR
• Centre medial
• Collimate head of humerus, scapula, AC joints

Question 21

Transthoracic lateral imaging technique

Answer 21

• Raise uninjured arm over top head, elevating shoulder, patient hold breath at full inspiration
• Centre below axilla, slightly above level of nipple
• Collimate proximal third of humerus, scapula, humeral head, acromion process, clavicle

Question 22

Humerus & Shoulder pathologies

Answer 22

• Midshaft fracture humerus
• Pathological fracture humerus
• ORIF fractured humerus
• Fractured neck of humerus
• Gleno-humeral dislocation (anterior)
• Gleno-humeral dislocation (posterior)
• Calcified rotator cuff
• Bankart lesion
• Hill-Sachs lesion
• Fractured scapula
• Fractured clavicle
• Subluxed acromioclavicular joint

Question 23

Series for trauma shoulder (if patient can stand)

Answer 23

• AP shoulder
• Gleno-humeral oblique
• Y-lateral

Question 24

Series for trauma shoulder (if patient cannot stand)

Answer 24

• AP supine shoulder
• AP Y-lateral (if patient can be rolled)
• Transthoracic lateral (if patient can’t be rolled)

Question 25

Series for soft tissue (rotator cuff, impingement syndrome, etc.)

Answer 25

- AP shoulder - Gleno-humeral obliques with 15+ degrees caudal tube angle, internal and external rotation - Neer's lateral

Question 26

Series for suspected dislocation

Answer 26

- AP shoulder (erect or spine) - Y-lateral (PA erect of AP supine) - Axial view (post enlocation if possible)