Introduction: Tears of the anterior cruciate ligament (ACL) are common among young athletes and diagnosis may be difficult especially in the young population. Therefore, finding a new method to increase the correct diagnosis is necessary.

Materials and Methods: This double-blind prospective observational study was conducted on 51 patients with suspected ACL rupture. In this study, in addition to the standard protocols, the oblique-sagittal and oblique-coronal MRI were assessed and used in three different methods, including A method (orthogonal MRI protocol), B method (orthogonal MRI protocol and oblique-sagittal MRI), and C method (orthogonal MRI protocol and oblique-coronal MRI).

Results: In detecting both complete and partial rupture of ACL, B method had highest diagnostic accuracy (kappa = 0.338, P=0.001), and after that, C method had acceptable accuracy (kappa = 0.292, P=0.011). In addition, in detecting a partial rupture of ACL, B method (kappa = 0.5, P<0.001), and C method had acceptable accuracy (kappa = 0.361, P=0.006). Meanwhile, in detecting a complete rupture of ACL, B method had the highest diagnostic accuracy (kappa = 0.898, P<0.001), and subsequently A method had significant accuracy (kappa = 0.812, P<0.001).

Conclusions: Our results showed that the evaluation of ACL rupture by oblique-sagittal MRI in addition to orthogonal MRI protocol is accurate and with high sensitivity and specificity values. It allows to find abnormal images immediately with higher accuracy in the emergency department and more critically ill patients may benefit from the advantages of this imaging protocol.