Clinically appropriate, cost-effective MR scan of the acute knee injury.

MR scan of the knee is a valuable diagnostic aid in evaluation of the acute knee injury. Skilled clinically examination, in conjunction with a technically good MR scan of the acute knee injury, is a cost-effective method in the treatment plan. MR, used as a substitute for a clinical examination by a skilled physician, is overutilization of a valuable resource. The clinician who uses MR scan in the acute knee injury should be familiar with the sensitivity, specificity, and accuracy of the MR scan in this setting.