Projections

AP Humerus

CR Location & Positioning

• SID: 40 inches (102 cm)
• Patient position: Upright preferred (standing or seated) or supine if necessary. Place the back against the upright Bucky or table.
• Adjustments: Abduct the arm slightly and supinate the hand. Align humeral epicondyles parallel with the IR plane so the shoulder and elbow are in the same horizontal plane.
• CR (angle and centering): Perpendicular to mid-humerus, centered midway between shoulder and elbow.
• Patient instructions: Suspend respiration during exposure.
• Exposure: Use 70–85 kVp range. Collimate to include the entire humerus and both joints.

Evaluation Criteria

• Coverage: Entire humerus including shoulder and elbow joints visible; 1 inch of forearm and entire shoulder joint included.
• Rotation checks: Humeral epicondyles seen in profile; greater tubercle in profile laterally; lesser tubercle between humeral head and greater tubercle.
• Motion checks: Sharp bony margins and trabecular detail indicate no motion.
• Technique checks: Uniform brightness and contrast from proximal to distal; soft tissue and bone detail visible; no artifacts.
• Clinical aim: Demonstrates humeral shaft and shoulder articulation for trauma, pathology, or degenerative evaluation.

Lateral Humerus

CR Location & Positioning

• SID: 40 inches (102 cm)
• Patient position: Upright or supine.
• Adjustments: Flex the elbow 90 degrees and internally rotate the arm so the palm rests on the hip, placing epicondyles perpendicular to the IR.
• CR (angle and centering): Perpendicular to mid-humerus, centered midway between shoulder and elbow.
• Patient instructions: Suspend respiration.
• Exposure: 70–85 kVp, same technique range as AP for comparison.

Evaluation Criteria

• Coverage: Entire humerus including shoulder and elbow joints.
• Rotation checks: Humeral epicondyles superimposed; lesser tubercle in profile medially; greater tubercle superimposed over humeral head.
• Motion checks: Sharp humeral outline and trabecular pattern.
• Technique checks: Even brightness and contrast; visible soft tissue and bony trabeculae.
• Clinical aim: Demonstrates the entire humerus in a true lateral projection; used for trauma, dislocation, or alignment assessment.

Transthoracic Lateral Humerus (Lawrence Method)

CR Location & Positioning

• SID: 40 inches (102 cm)
• Patient position: Upright or supine lateral, affected arm against the upright Bucky. Raise the unaffected arm above the head to clear the humerus.
• Adjustments: Ensure the midcoronal plane is perpendicular to the IR. If the patient cannot elevate the arm fully, angle the CR 10–15° cephalad.
• CR (angle and centering): Perpendicular to the surgical neck (or angled 10–15° cephalad if limited mobility).
• Patient instructions: Perform shallow breathing during exposure if possible; otherwise suspend respiration.
• Exposure: Use a long exposure time (3–5 seconds) with low mA to blur ribs and lung markings.

Evaluation Criteria

• Coverage: Proximal humerus and shoulder joint included; entire shaft if possible.
• Rotation checks: Epicondyles superimposed; minimal rib superimposition over the humerus.
• Motion checks: Ribs appear blurred with breathing technique; humerus remains sharply defined.
• Technique checks: Adequate penetration through thorax; soft tissue and bone detail visible.
• Clinical aim: Used when fracture or immobilization prevents conventional lateral positioning; demonstrates the proximal humerus without moving the injured limb.

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