AP PROJECTION: HUMERUS

Warning:

• Do not attempt to rotate arm if fracture or dislocation is suspected.

Pathology Demonstrated:

• Fracture and dislocation of the humerus, as well as other pathologic processes such as osteoporosis and arthritis, are demonstrated.

Technical Factor:

• IR size - lengthwise (large enough to include entire humerus)
• For larger patient, 35 x 43 cm (14 x 17 inches) may be needed to place cassette diagonally to include both joints
• For smaller patient, 30 x 35 cm (11 x 14 inches)
• Moving or stationary grid (non-grid, detail screen for smaller patient)
• 70+- 6 kV range

Shielding:

• Secure or place lead shield over pelvic area.

AP Humerus Erect

Patient Position:

• Position patient erect or supine. Adjust height of cassette so that shoulder and elbow joints are equidistant from ends of IR.

Part Position:

• Rotate body towards affected side as needed to bring shoulder and proximal humerus in contact with cassette.
• Align humerus with long axis of IR, unless diagonal placement is needed to include both shoulder and elbow joints.
• Extend hand and forearm as far as patient can tolerate.
• Abduct arm slightly and gently supinate hand so that epicondyles of elbow are equidistant from IR.

AP Supine Note that the hand is supinated

Central Ray:

• CR perpendicular to IR, directed to midpoint of humerus
• Minimum SID of 40 inches (100cm)

Collimation:

• Collimate on sides to soft tissue borders of humerus and shoulder. (Lower margin of collimation field should include the elbow joint and about 2.5 cm [1 inch] minimum of proximal forearm.)

Respiration:

• Suspend respiration during exposure

..................................................................................
Radiographic Criteria:

AP Humerus Erect

Structure Shown:

• AP projection of the entire humerus, including the shoulder and elbow joints, is visible.

Position:

• Long axis of humerus should be aligned with long axis of IR.

True AP projection is evidenced at proximal humerus by the following:

• Greater tubercle is seen in profile laterally.
• Humeral head is partially seen in profile medially, with minimal superimposition of the glenoid cavity.
• Distal Humerus: Lateral and medial epicondyles both are visualized in profile.

Collimation and CR:

• Collimation borders are visible at the skin margins along the length of the humerus, with minimal collimation at both ends to ensure that essential joint anatomy is included.
• CR and center of collimation field should be to the approximate midpoint of the humerus.

Exposure Criteria:

• Optimal density and contrast with no motion visualize sharp cortical margins and clear, bony trabecular markings at both proximal and distal portions of the humerus.