Clavicle AP is a radiography positioning projection of the Upper Extremity. Erect or supine, arm at side. CR perpendicular to clavicle midshaft. SID 40". Include entire clavicle. The centering point is located midshaft of the clavicle, midway between the SC and AC joints. The central ray is perpendicular to the midshaft of the clavicle. Image-quality criteria include entire clavicle from sternal end to acromion visualized, clavicle shown in one plane without foreshortening. A sample technique is 81 kVp with DR 5 or CR 10 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Entire clavicle from sternal to acromial end.
- Sternoclavicular joint medially.
- Acromioclavicular joint laterally.
- Medial third of the clavicle.
- Lateral third of the clavicle.
Patient preparation
- Verify patient identity using two identifiers.
- Remove necklaces and other radiopaque objects from the region to be radiographed.
- Position patient erect or supine, with the posterior shoulder against the IR or tabletop and no rotation.
- WARNING: suspected fracture or destructive disease: Merrill's uses the supine position to reduce the possibility of fragment displacement or additional injury. Bontrager allows erect or supine.
- Keep arms at sides in a relaxed position.
- Straighten spine and keep shoulders level.
Position & centering point
Midshaft of the clavicle, midway between the SC and AC joints.
Central ray
Perpendicular to the midshaft of the clavicle.
Exposure / technique
- kVp
- 81
- mAs
- DR 5 / CR 10
- SID
- 40" (102 cm)
- Notes
- Erect or supine. Entire clavicle from sternal end to acromion must be included on the radiograph. Breathing: Bontrager suspends at the end of inhalation, which helps elevate the clavicles; Merrill's suspends at the end of exhalation for a more uniform-density image. Sample technique: DR 5 / CR 10 mAs at 81 kVp, 40 in SID, for a 16 cm part. Adjust for your equipment.
kVp and mAs are sample values. Use caution when applying them in your department.
Image-quality criteria
- Entire clavicle from sternal end to acromion visualized.
- Clavicle shown in one plane without foreshortening.
- Midclavicle superimposed on the superior scapular angle (Merrill's: lateral half above the scapula, medial half over the thorax).
- Sternal end sharp and well-defined.
- Distal clavicle and acromioclavicular joint included.
- Collimation: to the clavicle, including both AC and SC joints (Bontrager); include 1.5 inches above the shoulder and 1 inch beyond its lateral aspect (Merrill's).
Common errors
- 1 Shoulders not in the same horizontal plane.
- 2 Body rotated: the posterior shoulder should contact the IR or tabletop without rotation.
- 3 Field set too tight, cutting off the AC or SC joint: both must be included.
- 4 CR not at the midclavicle, so the entire clavicle is not centered on the image.
Clinical indications
- Clavicular fracture evaluation across entire bone.
- Clavicular dislocation.
- Destructive disease of the clavicle.