Saturday, March 14, 2009

How to do ankle x-rays?

Patient lies supine on the table.
For AP, straightened both his legs by pulling both of them down slightly. The foot is in neutral position with slight medial rotation. Place a suitable size cassette below his ankle. You may split a 10x12" cassette into 2 to accomodate both AP & lateral views. No grid is used.
The central ray is perpendicular to the ankle joint at a point midway between the 2 malleoli. See cross mark in the image above.
For lateral view, turn the patient slightly by lifting his opposite buttock. The knee should be in lateral position making an angle of about 120 degrees. Centre at medial malleolus.
Exposure for AP is about 55 kVp and 3 mAs. For lateral view, the kVp is about 52 and mAs is also 2.
FFD is 100 cm.

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