76 magnetic resonance (MR) studies of the knee were reviewed to evaluate the diagnostic
validity of MR imaging compared with the arthroscopic findings and to identify the characteristic findings of acute versus chronic anterior cruciate ligament tears on MR imaging.
The sensitivity, specificity, accuracy, negative predictive value and positive predictive value 84.2%, 90.0%, 86.2%, 94.1% and 75% respectively for acute anterior cruciate ligament tears and 86.4%, 100%, 93.6%, 100% and 89.3% respectively for chronic tears.
In acute anterior cruciate ligament tears, MR imaging showed discontinuity with or without high signal intersity of the ligament, high signal intersity without discontinuity and high signal intersity at the lateral comparetment of the knee on T2 images.
In chronic tears, MR imaging showed discontinuity, irregular contour and attenuation of the ligament.
High bone signal intersity on the lateral compartment of the knee and high signal intersity in the anterior cruciate ligament were characteristic findings of acute anterior cruciate ligament tears.
|