Measurement of spinal root angle at spinal canal and foraminal levels in cases of facet arthropathy: T2-weighted turbo spin echo magnetic resonance myelography with SPACE technique

Abstract

Background

Magnetic resonance myelography (MRM) with three-dimensional (3D) T2-weighted (T2W) turbo spin echo (TSE) sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) may be a guide to the etiology of low back pain.

Purpose

To research the efficiency of a 3D T2W TSE SPACE MRM sequence for visualization of anatomic details of spinal nerve root at the spinal canal and lateral recess levels in the patients with low back pain.

Material and Methods

Lumbar spinal MRM 3D T2W TSE SPACE was performed in a total of 70 patients (median age 46 years). Patients were imaged while lying in a supine position with straightened legs. According to the degree of facet arthropathy findings, patients were divided into four separate subgroups in our retrospective cross-sectional study. Spinal nerve root angle was measured within the spinal canal and at lateral recess level, and facet joint angle and lumbar lordosis measurements were measured by two radiologists, independently.

Results

Lumbar level was strongly negatively correlated with facet joint angle (r = −0.95) as well as nerve root angle within the spinal canal (NRA_SC) (r = –0.857) and at the lateral recess level (NRA_LR) (r = −0.947). Intracanal decline of the spinal root angle caused by spinal stenosis findings was also observed (P < 0.05). For the measurements of NRA_SC and NRA_LR, inter-observer correlation was 0.85 and 0.82 for the spinal canal and at lateral recess level, respectively.

Conclusion

3D T2W SPACE in NRA_SC and NRA_LR provided high resolution images for evaluation. Therefore, this method may be a qualitative guide for the clinician and the surgeon in terms of root anatomy before any intervention.