Pathology Demonstrates:
- Fracture and dislocation of elbow and some bony pathologic processes, such as osteomyelitis and arthritis, are shown. Elevated or displaced fat pads of the elbow joint may be visualized.
- IR 18 x 24 cm (8 x 10 inches), crosswise
- Detail screen, tabletop
- Digital IR - use lead masking
- 60 or add upto 6kV range
- Place lead shield over patient's lap to protect gonads.
Patient Position:
- Seat patient at end of table, with elbow flexed 90degrees (see note).
Part Position:
- Align long axis of forearm with long axis of cassette.
- Center elbow joint to CR and to center of IR.
- Drop shoulder so that humerus and forearm are on same horizontal plane.
- Rotate hand wrist into the true lateral position, thumb side up.
- Place support under hand and wrist to elevate hand and distal forearm as needed for heavy muscular forearm, so that forearm is parallel to IR for true lateral elbow.
Central Ray:
- CR perpendicular to IR, directed to mid elbow joint (a point approximately 4 cm [1 1/2 inches] medial to easily palpated posterior surface of olecranon process)
- Minimum SID of 40 inches (100cm)
Collimation:
- Collimate on four sides to area of interest.
Note:
- Diagnosis of certain important joint pathologic processes (such as possible visualization of the posterior fat pad) depends on 90degrees flexion if the elbow joint.*
Exception:
- Certain soft tissue diagnoses require less flexion (only 30 to 35degrees), but these views should be taken only when specifically indicated.
Radiographic Criteria:
Structure Shown:
- Lateral projection of distal humerus and proximal forearm, the olecranon process, and the soft tissues and fat pads of the elbow joint are visible.
Position:
- Long axis of the arm should be aligned with the long axis of the IR, with the elbow joint flexed 90degrees.
- About one half of the radial head should be superimposed by the coronoid process, and the olecranon process should be visualized in profile.
- A true lateral is indicated by three concentric arcs of the trochear sulcus, double ridges of the capitulum and trochlea, and the trochlea notch of the ulna. In addition, superimposition of the humeral epicondyles occurs.
Collimation and CR:
- Collimation should be visible on four sides to area of affected elbow.
- CR and center of collimation field should be midpoint of the elbow joint.
Exposure Criteria:
- No motion and optimal density and contrast should visualize sharp cortical margins and clear trabecular markings, as well as soft tissue margins of the anterior and posterior fat pads.
