Magnetic resonance imaging of the cervical ligaments in the absence of trauma

Study Design. Prosepective study of cervical spine magnetic resonance imaging. Objectives. To determine the frequency of nonvisualization of the cervical spinal ligaments in patients who have not suffered acute spinal trauma. Summary of Background Data. The cervical ligaments appear on magnetic resonance studies as a thin hypointense line, the "black stripe." Discontinuity of this "black stripe" is considered a reliable sign of ligament rupture following acute spinal trauma. Methods. Twenty patients ( 13 female and 7 male, mean age 45.5 years, range 28 - 58 years) undergoing magnetic resonance imaging for cervical degenerative disc disease were examined using sagittal T1- and T2-weighted fast spin echo sequences. The status of the anterior longitudinal ligaments and posterior longitudinal ligaments was assessed on T1- weighted images from C2 to T1 ( total of 120 levels), the ligamentum flavum from C1 to T1 ( 140 levels), and the apical ligament on both T1 and T2 weighted images ( 20 levels). The presence and sites of degenerative change were also noted. Results. On the T1- weighted images, only 74 - 79% of anterior longitudinal ligaments, 36 - 74% of posterior longitudinal ligaments, 63 - 65% of ligamentum flavums, and 35 - 60% of apical ligaments were visualized. On T2-weighted images, all the apical ligaments were seen. An association was identified between nonvisualization of the anterior longitudinal ligaments on T1 and the presence of anterior osteophytes. Conclusion. Discontinuity of the "black stripe" on a T1- weighted sequence cannot be used as a reliable isolated sign of ligament rupture in the setting of acute spinal trauma, because the spinal ligaments are commonly not visualized.