Elbow AP Oblique (medial rotation)
Pathology Demonstrated:- Fracture and dislocations of the elbow, primarily the coronoid process, and some pathologic processes, such as osteoporosis and arthritis, are shown.
Medial (Internal rotation) Oblique
- Best visualizes coronoid process of ulna and trochlea in profile
Technical Factor:
- IR sizr - 24 x 30 cm (10 x 12 inches)
- Detail screen, tabletop, division in half crosswise
- Digital IR - use lead masking
- 60 or add upto 6 kV range
Shielding:
- Place lead shield over patient's lap to protect gonads.
Patient Position:
- Seat patient at end of table, with arm fully extended and shoulder and elbow on same horizontal plane.
Part Position:
- Align arm and forearm with long axis of portion of IR that is being exposed. Center elbow joint to CR and to portion of IR being exposed.
- Pronate hand into a natural palm-down position and rotate arm as needed until distal humerus and anterior surface of elbow are rotated 45degrees ( while palpating epicondyles to determine a 45degrees rotation of distal humerus).
Cenral Ray:
- CR perpendicular to IR, directed to mid elbow joint (approximately 2cm [3/4 inch] distal to midpoint of the line between epicondyles as viewed from the x-ray tube)
- Minimum SID of 40 inches (100 cm)
Collimation:
- Collimate on four sides to area of interest.
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Radiographic Criteria:
Structure Shown:
- Oblique view of the distal humerus and proximal radius and ulna is visible.
Position:
- Long axis of arm should be aligned with side border of IR.
- A correct 45 degrees medial oblique should visualize the coronoid process of the ulna in profile.
- Radial head and neck should be superimposed and centered over the proximal ulna.
- The medial epicondyle and the throchlea should appear elongated and partial profile.
- The olecranon process should appear seated in the olecranon fossa and the trochlea notch partially open and visualized with the arm fully extended.
Collimation and CR:
- Collimation should be visible on four sides to area of affected elbow.
- CR and center of collimation field should be at mid elbow joint.
Exposure Criteria:
- Optimal density and contrast with no motion should visualized soft tissue detail and bony cortical margins and clear, bony trabecular markings.
