Accuracy of fat-suppressed three-dimensional spoiled gradient-echo FLASH MR imaging in the detection of patellofemoral articular cartilage abnormalities.

Abstract

To determine the accuracy of T1-weighted fat-suppressed (FS) three-dimensional (3D) fast low-angle shot (FLASH) magnetic resonance (MR) imaging for the detection of articular cartilage abnormalities of the patellofemoral joint. Forty-one patients with suspected internal derangement of the knee were examined with a T1-weighted FS 3D FLASH sequence and subsequently underwent arthroscopy. The patellofemoral articular cartilage was graded blindly on both the MR and arthroscopic images with a modification of the Noyes classification scheme. For the detection of abnormal articular cartilage of the patellofemoral joint with the FS 3D FLASH sequence, sensitivity was 81%, specificity was 97%, and accuracy was 97%. Of the lesions detected on MR images, 77% were graded identically on MR and arthroscopic images. For the remaining 23%, MR imaging and arthroscopic ratings were within one grade of each other. T1-weighted FS 3D FLASH imaging is accurate for the detection and grading of articular cartilage abnormalities of the patellofemoral joint.