Contribution of thin slice (1 mm) oblique coronal proton density-weighted MR images for assessment of anteromedial and posterolateral bundle damage in anterior cruciate ligament injuries

Purpose: To evaluate the diagnostic efficacy of using additional oblique coronal 1 mm proton density-weighted (PDW) MR imaging of the knee for detection and grading anterior cruciate ligament (ACL), anteromedial bundle (AMB) and posterolateral bundle (PLB) injuries. Materials and methods: We prospectively assessed preoperative MR images of 50 patients (36 men, 14 women; age range, 18–62 years). First, we compared the diagnostic performance of routine sagittal (3 mm) and additional oblique coronal images (1 mm) for ACL tears. Then, we compared the tear types (AMB or PLB) and grade presumed from oblique coronal MR imaging with arthroscopy. Results: Arthroscopy revealed ACL tear in 24 (48%) patients. There was significant difference between sagittal images and arthroscopy results for ACL tear recognition (p < 0.001). No significant difference was detected for oblique coronal images when compared with arthroscopy results (p = 0.180). Sensitivity and specificity values for ACL tear diagnosis were 37.04% and 95.65% for sagittal images; 74.07% and 91.30% for oblique coronal images. There was no significant difference between arthroscopy and oblique coronal MR images in grading AMB and PLB injuries (p > 0.05). Conclusion: Addition of thin slice oblique coronal images to conventional sequences could better contribute to better verifying the presence of ACL tear and in determining its grade