Scapula (AP view)
The scapula AP view is a specialized projection of the scapular bone, performed in conjunction with the lateral scapular view. This projection can be performed erect or supine, involving 90-degree abduction of the affected arm.
This view is rarely requested due to the accessibility of CT and the ability to inspect the scapula on shoulder radiographs. However, it can be requested and performed for the 'better look' at the scapula if there is a suspected fracture or lesion.
- the patient is preferably erect however this can be performed supine
- the midcoronal plane of the patient is parallel to the image receptor, in other words, the patient's back is against the image receptor
- scapula of the affected side is at the center of the image receptor
- affected sides arm is abducted with the hand in supination, this action will 'pull' the scapula away from ribs
- the patient is slightly rotated 5°, therefore, the body of the scapula is laying parallel with the image receptor
- anteroposterior projection
- centering point
- 5 cm inferior to the coracoid process
- superior to the skin margins
- inferior to include the inferior margin of the scapula
- lateral to include the skin margin
- medial to include 1/2 of the clavicle
- detector size
- 24 cm x 30 cm
- 60-70 kVp
- 10-18 mAs (with 3 seconds breathing see mAs for more details)
- a breathing technique is the most effective way to perform this projection
- 100 cm
- yes (this can vary departmentally)
Image technical evaluation
- the scapula should be clearly visualized, free from any motion blur
- the medial border is superimposed by the ribs
- the lateral border should be free from any superimposition
- no foreshortening of the scapular body (as per the patient rotation discussed in the positioning)
A rarely performed projection, however, valuable to be aware of in the setting of trauma without a CT scanner. Patients may not be able to fully abduct their arm due to pain, this is something that should be taken into consideration when setting up the patient (abduct the arm last!).
The breathing technique is important in this protection to blur out thoracic structures whilst maintaining a sharp image of the scapula.