Where is the cr centered for the ap oblique (grashey method) position for the glenoid cavity?

Last revised by Amanda Er ◉ on 02 May 2022

Citation, DOI & article data

Citation:

Morgan, M., Er, A. Shoulder (AP glenoid view). Reference article, Radiopaedia.org. (accessed on 08 Sep 2022) https://doi.org/10.53347/rID-35615

The shoulder AP glenoid view also known as a true AP or a 'Grashey view' is an additional projection to the two view shoulder series. The projection is used to assess the integrity of the glenohumeral joint.

On this page:

The glenoid view is an ideal projection to inspect the glenoid rim, the glenohumeral joint and the articular surface of the humerus. This view is great to inspect the joint space for subtle fractures such as a bankart lesion post-dislocation-relocation, to look for proximal migration of humerus, as a general joint space assessment, or during post-operative evaluation.

• the patient is preferably erect
• the midcoronal plane of the patient is parallel to the image receptor, in other words, the patient's back is against the image receptor
• the glenohumeral joint of the affected side is at the center of the image receptor
• patient is turned toward the affected side to show the glenohumeral joint space; this is achieved by rotating the patient 30-45°
• affected arm is internally rotated

• anteroposterior projection
• centering point
  • 2.5 cm inferior to the coracoid process, or 2 cm inferior to the lateral clavicle at the level of the glenohumeral joint
• collimation
  • superior to the skin margins
  • inferior to include one-third of the proximal humerus
  • lateral to include the skin margin
  • medial to 1/3 of the medial clavicle
• orientation  
  • portrait
• detector size
  • 18 cm x 24 cm
• exposure
  • 60-70 kVp
  • 10-18 mAs
• SID
  • 100 cm
• grid
  • yes (this can vary departmentally)

• the glenohumeral joint should be open
• the anterior and posterior aspects of the glenoid are superimposed
• the coracoid process is foreshortened
• no foreshortening of the scapular body (as per the patient rotation discussed in the positioning)

Rotation of the patient will vary due to body habitus, and this is an obvious point but highly relevant. Patients who require these films are often suffering from either chronic or acute shoulder pain and palpating the affected shoulder is far from ideal. It's advisable to observe the clavicle when rotating the patient until the midshaft of the clavicle is almost end on.

Quiz questions

Related articles: Imaging in practice

Promoted articles (advertising)

Where should the CR be located for an AP projection of the shoulder joint?

When performing an AP oblique shoulder image Grashey method the patient should be rotated how many degrees?

Where is the CR centered for a transthoracic lateral projection?