Concurrent use of oblique sagittal and oblique coronal MRI: does it enhance the specificity and the accuracy of diagnosing complete and partial ACL tears?

Abstract

Background: The aim of the study was to evaluate the diagnostic efficacy of utilization of oblique sagittal and oblique coronal MRI techniques separately and concurrently in improving the diagnosis of anterior cruciate ligament (ACL) complete and partial tears. Between December 2017 and November 2018, 71 patients, with suspected ACL injury, were examined by MRI using four diagnostic approaches: standard routine images only (approach A), standard and oblique coronal images (approach B), standard and oblique sagittal images (approach C), and standard images with both oblique coronal and sagittal images (approach D). Two experienced musculoskeletal radiologists evaluated the MRI images separately and in a random order using the four methods, and findings were compared with arthroscopy results as a gold standard. Results: The diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for approach A in diagnosis of partial ACL tear was significantly lower than that for approaches B, C, and D (p value < 0.05). The PPV and NPV for approaches B (82% and 85%) and C (83% and 87%) in diagnosis of partial ACL tear which were significantly lower than that for approach D (94% and 95%). The four approaches revealed no significant difference in diagnosis of complete ACL tear (p value > 0.05). Approach D demonstrated highest interobserver agreement (94% in complete and 88% in partial ACL tears) in comparison to B (79% in complete and 66% in partial) and C (85% in complete and 71% in partial) when combining oblique sagittal and oblique coronal images in identifying both complete and partial ACL tears Conclusion: The addition of oblique sagittal and coronal images improved diagnostic accuracy of detection of complete and partial ACL tears. The concurrent use of sagittal and coronal oblique images enhanced the diagnostic efficacy of diagnosis of partial ACL tears only.