Comparison between 2D TSE and 3D SPACE in the evaluation of craniocervical ligaments

Purpose To evaluate the MRI findings of the craniocervical junction ligaments and compare the 2D TSE sequence and 3D SPACE sequence on cervical spine MRI. Methods Eighty cervical spine MRIs were retrospectively analyzed, including 2D TSE and 3D SPACE sequences. The visibility and morphology of the transverse ligament (TL) and alar ligament (AL) were evaluated by two readers using a five-point grading scale for visibility (1 = not visible, 2 = barely visible, 3 = adequately visible, 4 = good visibility, 5 = excellent visibility) and a four-point grading scale for morphology (0 = homogeneous low SI with normal thickness, 1 = high SI with normal thickness, 2 = reduced thickness, 3 = full-thickness rupture or indistinguishable from surrounding structures). The grades of the two sequences were compared. Reader agreements were measured using the percentage of exact agreement. Result The visibility grade of TL was significantly higher in 3D, indicating better visualization. The morphology grade of TL was significantly lower in the 3D, indicating more normal-appearing ligament. The exact agreements of visibility and morphology grade of TL tended to be higher in 3D. On the other hand, there was no significant difference in visibility grade of AL between the two sequences. The morphological grade of AL was significantly higher in 3D. The agreement of the morphological grade of AL tended to be lower in 3D. Conclusion The utilization of 3D sequences significantly improves the visibility of TL and could potentially reduce false-positive diagnoses of ligament injury.