Thorax and Abdomen
6 Sternoclavicular (SC) Joints
Anatomy
sternoclavicular joint, clavicular notch, acromioclavicular joint, acromial extremity, sternal extremity, acromion, coracoid process, scapula.
Projections
PA Sternoclavicular (SC) Joints
CR Location
40 inch SID. Patient positioned prone or erect with arms at their sides and palms facing posteriorly. CR should be centered to the midsagittal plane and directed perpendicular to T2-T3 (a point 3 inches inferior to the C7 spinous process, or at a level even with the top of the scapulae). Expose on suspended respiration.
Evaluation Criteria
No motion. SC joints should be demonstrated with no rotation as evidenced by equal distances of the SC joints from the vertebral column on both sides. The image should be collimated to include the medial third of both clavicles and the manubrium.
Anterior Oblique Sternoclavicular (SC) Joints
CR Location
40 inch SID. Patient positioned prone or erect with arms at their sides and palms facing posteriorly. Their body should be rotated 10-15 degrees with the side of interest facing the detector (e.g., RAO for the right SC joint, LAO for the left SC joint). CR is directed perpendicular to the IR at the level of T2-T3 (a point 3 inches inferior to the C7 spinous process, or at a level even with the top of the scapulae), and approximately 1-2 inches lateral from the midline towards the raised side (relative to the detector). Expose on suspended respiration.
Evaluation Criteria
No motion. SC joint of interest should be centered to the IR and well-visualized, with clear articulation between the clavicle and manubrium. Visualization of manubrium and downside SC joint free from superimposition by the vertebral column. The sternoclavicular joint on the side opposite the obliquity will be foreshortened and obscured by the bony thorax. Collimation should include the medial third of both clavicles, the sternoclavicular joints, and the manubrium, ensuring tight collimation to minimize scatter.
Hows & Whys of SC Joint Radiography
- How can you tell that a patient was not rotated on a image of PA SC joints?
- The sternoclavicular joints are equal distance from the vertebrae.
- How can you tell that the patient for PA SC joints is not rotated before you take the image?
- The shoulders are equal distance from the bucky.
- What bony landmarks can be used to position for SC joints?
- The top of the scapula or 3 inches below the vertebra prominens.
- What vertebral level are the SC joints located at?
- T2-3.
- How can you tell that the degree of obliquity was correct on anterior oblique projections of the SC joints?
- The joint of interest is visualized free from superimposition of other bony structures.
- On anterior obliques of the SC joints, which joint will be best visualized?
- The joint on the downside.
- If your pt. condition requires you to do posterior obliques of the SC joints, which joint will be best visualized?
- The joint on the upside.
- Why are posterior obliques less desirable than anterior obliques?
- More magnification and less detail.
- Why should posterior oblique images be taken on suspended respiration?
- To minimize motion