Shoulder AP Oblique, Grashey Method is a radiography positioning projection of the Upper Extremity. Body rotated 35-45 degrees. CR perpendicular to scapular plane. SID 40". The centering point is located glenoid cavity, with body rotated 35-45 degrees to position the scapula face-on.. The central ray is perpendicular to the scapular plane and glenoid cavity fossa.. Image-quality criteria include glenoid fossa imaged face-on, clearly open and unforeshortened., proximal humerus shown in profile without superimposition.. Standard exposure ranges from 70 to 80 kVp, 6 to 12 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Glenoid cavity and fossa in profile.
- Proximal humerus and humeral head.
- Coracoid process projecting anteriorly.
- Scapular body and spine.
- Acromioclavicular joint.
- Shoulder soft tissues.
Patient preparation
- Verify patient identity using two identifiers.
- Remove watches, bracelets, and radiopaque items from shoulder.
- Position patient erect, posterior shoulder to IR.
- Rotate body 35-45 degrees, affected shoulder toward IR.
- Place hand of affected arm on opposite shoulder.
Position & centering point
Glenoid cavity, with body rotated 35-45 degrees to position the scapula face-on.
Central ray
Perpendicular to the scapular plane and glenoid cavity fossa.
Exposure / technique
- kVp
- 70–80
- mAs
- 6–12
- SID
- 40" (102 cm)
- Notes
- Erect technique. Body obliquity must be 35-45 degrees for proper scapular plane alignment.
Image-quality criteria
- Glenoid fossa imaged face-on, clearly open and unforeshortened.
- Proximal humerus shown in profile without superimposition.
- Coracoid process visible projecting anteriorly.
- Scapular body superimposed over the glenoid cavity.
- No excessive rotation or insufficient obliquity.
- Collimation: 3 inches on all sides of the shoulder joint.
Common errors / ARRT traps
- 1 Insufficient rotation fails to open the glenoid cavity properly.
- 2 Excess rotation rotates the glenoid superiorly or inferiorly.
- 3 Patient arm not positioned on opposite shoulder changes joint alignment.
- 4 Hand position across body closes the shoulder joint space.
- 5 Off-centered CR misses the glenoid or humeral head.
Clinical indications
- Anterior humeral head dislocation or subluxation.
- Glenoid cavity fracture evaluation.
- Rotator cuff or labral pathology assessment.
- Glenohumeral joint instability evaluation.
Aligned to the 2025 ARRT Content Specifications.