Shoulder Scapular Y

• Scapular body forming the lower arm of the Y.
• Acromion and coracoid forming the upper arms of the Y.
• Acromion process at the superior junction.
• Coracoid process visible.
• Humeral head at the Y intersection in a normal shoulder.
• Proximal humerus in profile.

• WARNING: do not attempt to rotate the arm if a fracture or dislocation is suspected; leave the affected arm as presented (Bontrager).
• Verify patient identity using two identifiers.
• Remove watches, bracelets, and radiopaque items from shoulder.
• Erect (usually more comfortable) or recumbent, facing the IR in an anterior oblique as for a lateral scapula.
• Palpate the superior angle of the scapula and the AC joint, and rotate the patient until a line between them is perpendicular to the IR (45 to 60 degrees of obliquity, varying between patients).
• Centre the scapulohumeral joint to the CR and to the centre of the IR.
• Abduct the arm slightly if possible so the proximal humerus does not overlie the ribs; do not attempt to rotate the arm.
• Suspend respiration during the exposure.

Scapulohumeral joint, 2 inches (5 cm) below the AC joint, centred to the CR and the centre of the IR.

Perpendicular to the IR, directed to the scapulohumeral joint (2 inches [5 cm] below the AC joint).

kVp

85

mAs

DR 10 / CR 18

SID

40" (102 cm)

Notes

Erect position is usually more comfortable for the patient. The arm hangs at the side and may be abducted slightly so the humerus does not overlie the ribs; never attempt to rotate it. Breathing suspended. Sample technique: DR 10 / CR 18 mAs at 85 kVp, 40 in SID, for a 24 cm part. Adjust for your equipment.

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

• Thin scapular body seen on end, free of rib superimposition.
• Humeral head superimposed over the base of the Y if not dislocated; beneath the coracoid in an anterior dislocation, beneath the acromion in a posterior one.
• Acromion process visible at the superior arm of the Y.
• Coracoid and acromion form the upper arms of the Y, the scapular body the stem.
• Acromion and coracoid nearly symmetric as the upper arms of the Y.
• Collimation: four sides to the area of interest (Bontrager); 12 inches in length and 1 inch beyond the lateral shadow (Merrill's).

1. 1 Insufficient body obliquity skews the Y and superimposes the humeral head.
2. 2 Insufficient scapular Y formation from rotation or arm position.
3. 3 Patient breathing motion blurs the image during exposure.
4. 4 Off-centered CR misses the Y junction.
5. 5 Body position too lateral or oblique distorts the Y symmetry.
6. 6 Body obliquity off: the line from superior scapular angle to AC joint must be perpendicular to the IR.
7. 7 Scapular body not seen on end, so the ribs superimpose it.
8. 8 CR not at the scapulohumeral joint, 2 inches below the AC joint.
9. 9 Acromion and coracoid not nearly symmetric as the upper limbs of the Y.

• Anterior or posterior humeral head dislocation evaluation.
• Shoulder trauma follow-up with suspected dislocation.
• Proximal humeral fracture assessment.