MRI of knee ligaments.

The stability of the knee depends on the integrity of its ligaments. Pain, clinical history, and nonspecific physical findings may hinder clinical diagnosis of acute ligamentous injury. Most major knee ligaments have uniform low signal intensity on all imaging sequences, and diagnosis of injury is based on periligamentous soft tissue edema, increased signal within the ligament, or disrupted structures. Correlation of of findings from routine sagittal, coronal, and axial MRI scans usually yields a definitive diagnosis of knee ligamentous injury. This article reviews normal anatomy, function, mechanism of injury, and normal and pathological MRI findings of the major knee ligaments.