MRI Diagnosis of Anterior Cruciate Ligament Tears: What is the Added Value of Oblique Sagittal Technique?, SALLY E. AHMED and MANAR H. ABD EL-SATTAR
Abstract
Background: The Anterior Cruciate Ligament (ACL), is a key structure in the knee joint and one of the most frequently injured in clinical practice. Conventional Magnetic Resonance Imaging (MRI) is the preferred method for the diagnosis of ACL and associated injuries. However, the sensitivity and specificity of standard MRI for the detection of partial ACL tears is low.
Purpose: To assess the diagnostic efficacy of additional oblique sagittal MR images for MRI diagnosis of Anterior Cruciate Ligament (ACL) tears.
Patients and Methods: We prospectively evaluated 51 patients who were referred to the MRI unit because of trauma of knee soft tissue structures. MR images were interpreted using two methods: Standard images (method A); and standard images together with additional oblique sagittal images (meth-od B). The condition of the ACL (normal or tear) was estimated. The findings were compared with the arthroscpoic results as a golden standard.
Results: Standard knee MR protocol (method A) was positive in 44 out of 51 cases (86.3%), with 18 cases diagnosed as complete tear (35.3%), 26 cases were diagnosed as partial tear (51.0%). Whereas, using method B: 18 cases were diag-nosed as complete tear (35.3%), 31 cases were diagnosed as partial tear (60.8%) and two cases were normal (3.9%). Both methods achieved similar results in detection of complete ACL tear. However there was statistically significant difference between the two methods regarding the diagnosis of partial tear of the ACL (p-value <0.016).
Conclusion: Adding oblique sagittal technique to the standard MR imaging improved diagnostic accuracy for diagnosing partial ACL tear. However, oblique sagittal tech-nique is as efficient as standard MRI for the evaluation of complete ACL tear. Thus, suggesting the use of additional oblique-sagittal images in cases of suspicion of partial ACL tear.