Shoulder AP

• Proximal third of the humerus.
• Glenoid cavity and fossa.
• Humeral head and neck.
• Coracoid process projecting anteriorly.
• Acromion and lateral two-thirds of the clavicle.
• Upper scapula.

• WARNING: do not attempt to rotate the arm if a fracture or dislocation is suspected (Bontrager, Merrill's); Bontrager performs it in neutral rotation, arm as is.
• Verify patient identity using two identifiers.
• Remove watches, bracelets, and radiopaque items from the shoulder.
• Erect (usually less painful) or supine, posterior shoulder against the IR; rotate the body slightly toward the affected side if needed to bring the shoulder into contact with the IR.
• Centre the scapulohumeral joint to the centre of the IR.
• Abduct the extended arm slightly and externally rotate it (supinate the hand) until the epicondyles of the distal humerus are parallel to the IR. Internal rotation (hand pronated, epicondyles perpendicular to the IR) is the second view; do not rotate the arm if a fracture or dislocation is suspected.
• Suspend respiration during the exposure.

1 inch (2.5 cm) inferior to the coracoid process, which lies about 2 inches (5 cm) inferior to the lateral end of the AC joint; the scapulohumeral joint is centred to the IR.

Perpendicular to the IR, directed to 1 inch (2.5 cm) inferior to the coracoid process.

kVp

85

mAs

DR 4.5 / CR 10

SID

40" (102 cm)

Notes

Erect position is usually less painful for the patient. External rotation shows the greater tubercle in profile laterally; internal rotation shows the lesser tubercle in profile medially. Sample technique: DR 4.5 / CR 10 mAs at 85 kVp, 40 in SID, for an 18 cm part. Adjust for your equipment.

kVp and mAs are sample values. Use caution when applying them in your department.

• External rotation: greater tubercle in profile laterally; internal rotation: lesser tubercle in profile medially.
• Proximal humerus, lateral two-thirds of the clavicle, and upper scapula included.
• Coracoid process visible projecting anteriorly.
• Humeral head partially overlapping the glenoid cavity, as expected on an AP.
• Relationship of the humeral head to the glenoid cavity shown.
• Collimation: four sides, with the lateral and upper borders at the soft tissue margins (Bontrager); about 10 x 12 inches (Merrill's).

1. 1 Wrong humeral rotation for the question: external shows the greater tubercle, internal the lesser.
2. 2 Epicondyles not parallel to the IR in external rotation, so the greater tubercle is not in profile.
3. 3 Rotating the arm when a fracture or dislocation is suspected; use neutral rotation.
4. 4 Off-centered CR clips the coracoid or proximal humerus.
5. 5 Inadequate collimation includes excessive scapula or arm.
6. 6 CR not 1 inch inferior to the coracoid process.

• Suspected shoulder dislocation or subluxation.
• Proximal humeral fracture evaluation.
• Calcium deposits in muscles, tendons, or bursal structures.
• Shoulder joint degenerative changes or arthritis.