Leg length determination by CT digital radiography.

CT digital radiography is a new accurate technique for measuring leg length discrepancy. It is easily performed on commercially available equipment with a radiation dose of 3-6 times less than the conventional technique. Because of the short time required to complete the examination, charges are comparable with those for existing procedures. Good correlation in total limb length measurements between this new technique and spot scanography was noted in 24 patients. CT digital radiography should be the preferred method for evaluation for limb length discrepancy, particularly in children, because of the simple technique and lowering of radiation dose.