Posterolateral aspect of the knee: improved MR imaging with a coronal oblique technique.

Abstract

PURPOSE: To determine if angling the coronal plane in magnetic resonance (MR) imaging of the knee increases the conspicuity of the posterolateral structures. MATERIALS AND METHODS: A coronal oblique MR imaging sequence performed parallel to the popliteal tendon proximally was added to our routine study in patient knee examinations. One hundred patients (age range, 12-72 years) underwent MR imaging. RESULTS: Coronal oblique images depicted the arcuate ligament in 46%, the fabellofibular ligament in 48%, and the fibular origin of the popliteal muscle in 53% of the patients, whereas standard coronal images depicted these in 10%, 34%, and 8% of the patients, respectively. Sagittal oblique images did not adequately depict these structures. CONCLUSION: Depiction of the structures in the posterolateral aspect of the knee was optimal on coronal oblique images. We advocate obtaining coronal oblique T2-weighted images in patients with either posterolateral knee pain or suspected injury to the posterolateral ligamentous structures.