Radiographic Positioning
| Adult |
| Other related pages of interest
|
| Name of projection | Forearm - AP |
| Area Covered | Radius, ulna, carpals, distal humerus |
| Pathology shown | Fractures, dislocations,and pathologic processes such as osteomyelitis or arthritis. |
| Radiographic Anatomy | Forearm Radiographic Anatomy |
| IR Size & Orientation | 24 x 30 for smaller patients 35 x 43 cm for larger patients Portrait, divided in 2 usually fits two forearm views, use lead masking for unused half |
| Film / Screen Combination | Regular (CR and DR as recommended by manufacturer) |
| Bucky / Grid | No |
| Filter | No |
| Exposure | 54 kVp, 3.2 mAs |
| FFD / SID | 100cm |
| Central Ray | Directed to mid forearm Perpendicular to IR |
| Collimation | Centre: Midforearm Shutter A: Including distal humerus to base of the first metacarpal Shutter B: Skin line |
| Markers | Distal and lateral Marker orientation AP |
| Shielding | Gonadal (check your department's policy guidelines) |
| Respiration | Not applicable |
| Positioning | -
Patient seated close to end of table -
Elbow fully extended -
Supinate hand (2nd to 5th metacarpal heads against IR) -
Entire limb in the same plane -
Shoulder at table level -
Align and centre forearm to long axis of IR Supinate hand (2nd to 5th metacarpal heads against IR) Elbow fully extended -
Check the humeral epicondyles are equidistant from the IR |
Critique
| Positioning - AP positioning of the wrist and hand is demonstrated by:
- Styloid of radius is in profile
- No or minimal superimposition of the distal radius and ulna
- No or minimal super-imposition of the metacarpal bases
- Humeral epicondyles equidistant to IR is demonstrated by:
- Ulnar styloid is posterior to the head of the ulna
- Proximal ulna super-imposes radial head by about half a centimetre
- Both epicondyles of humerus are demonstrated in profile at the edges of the distal humerus
- Capitulum-radius joint is party or entirely closed
- Radial head articulating surface is demonstrated
- Olecranon process is within the olecranon fossa
- Coronoid process is demonstrated on end
- Radial tuberosity in profile medially
- Long axis of forearm aligned with long axis of IR
- Radius and ulna are parallel
- The radial head, neck, and tuberosity slightly superimposed by the ulna
- Wrist and elbow joints spaces are open only partially because of beam divergence.
Area Covered
- Radius, ulna, carpals, metacarpal bases, humeral epicondyles, olecranon fossa
Collimation Centre: Midforearm Shutter A: Including all of the medial epicondyle of the humerus to base of the first metacarpal Shutter B: Skin line
Exposure - Bony trabecular patterns and cortical outlines are sharly defined
- Soft tissues are visualised
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| Special Notes | Position the joint closest to the fracture site in true AP |
Reference:
Textbook of Radiographic Postioning and Related Anatomy, Sixth Edition. Authors : Kenneth L. Bontrager, and John P. Lampignano. Copyright 2005 by Mosby, Inc.