Name of projection | Ankle - Medial Oblique (Internal Rotation) |
Area Covered | Distal 1/3 of the tibia and fiblua, proximal metatarsals, ankle joint, lateral and medial malleoli |
Pathology shown | fractures, joint effusion, dislocation, foreign body |
Radiographic Anatomy | Ankle Radiographic Anatomy |
IR Size & Orientation | 24 x 30cm Landscape, divided in two usually fits two ankle projections, use lead masking for unused area |
Film / Screen Combination | Detail (CR and DR as recommended by manufacturer) |
Bucky / Grid | No |
Filter | No |
Exposure | 60 kVp 3.2 mAs |
FFD / SID | 100cm |
Central Ray | Midway between the malleoli, in line with the medial malleolus Perpendicular to the IR |
Collimation | - Centre: Midway between the malleoli at the level of the tibiotalar joint
- Shutter A: Open to include the distal 1/3 of the fibula and the proximal metatarsals
- Shutter B: Open to include the lateral skin margins
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Markers | Distal and Lateral Marker orientation AP |
Shielding | Gonadal (check your department's policy guidelines) |
Respiration | Not applicable |
Positioning | - Patient's leg fully extended
- Lower leg in AP position, toes pointing up
- Internally rotate entire leg and foot until the long axis of the foot is 45° to the IR
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Critique
| Positioning
- The correct positioning is evidenced by
- The lateral and medial malleoli are shown in profile
- There is some minor imposition of the distal fibula over the tibia
- There lateral mortise space is open, as there is no superimposition of the talus over the fibula
- The tibiotalar joint space is open
Area Covered
- Distal 1/3 of the tibia and fiblua, proximal metatarsals, ankle joint, lateral and medial malleoli
Collimation
- Centre: Midway between the malleoli, in line with the medial malleolus
- Shutter A: Open to include the distal 1/3 of the fibula and the proximal metatarsals
- Shutter B: Open to include the lateral skin margins
Exposure
- Bony trabecular patterns and cortical outlines are sharply defined
- Soft tissues are visualised
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Special Notes | The effect of too little leg and foot rotation
- The image will look more like a Mortise Ankle view, that is
- The malleoli will be shown in profile
- The lateral mortise will be open
The effect of too much leg and foot rotation
- The medial mortise will be closed
- The lateral mortise will be closed
- The sinus tarsi will be shown
- The fibula will have virtually no talar superimposition
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