Evaluation of selective bundle injury to the anterior cruciate ligament: T2-weighted fast spin-echo 3-T MRI with reformatted 3D oblique isotropic (VISTA) versus 2D technique

OBJECTIVE. The purpose of this study was to compare the diagnostic utility of oblique sagittal and oblique coronal 3D volume isotropic turbo spin-echo acquisition (VISTA) images with that of 2D fast spin-echo (FSE) T2-weighted images in the diagnosis of selective bundle tears of the anterior cruciate ligament (ACL). MATERIALS AND METHODS. This retrospective study included 56 patients who underwent 2D FSE and 3D VISTA 3-T MRI of the knee before arthroscopic procedures. Images obtained with the two sequences were interpreted by two musculoskeletal radiologists independently, and the results were analyzed with the surgical diagnosis as the reference. RESULTS. Among the 56 patients with suspected ACL injury, the arthroscopic records revealed 14 cases (25%) of complete tear, four cases (7%) of selective posterolateral bundle tear, and three cases (5%) of selective anteromedial bundle tear. The contrast-to-noise ratio between the ACL and joint fluid for 3D VISTA was 1.97 times as high as that for 2D FSE (p < 0.001). The entire width evaluation and margin sharpness scores for 2D FSE were signifcantly higher than those for 3D VISTA for both readers (p < 0.05). No signifcant differences were found in sensitivity, specifcity, or accuracy of 2D FSE and 3D VISTA in the diagnosis of selective ACL tears (p > 0.05). CONCLUSION. The diagnostic utility of oblique sagittal and oblique coronal 3D VISTA sequences was similar to that of 2D FSE sequences in the MRI diagnosis of selective bundle tear of the ACL, but the image quality of 3D VISTA was inferior to that of 2D FSE.