Investig Magn Reson Imaging.  2024 Sep;28(3):114-121. 10.13104/imri.2024.0013.

The Effect of Scanning Order of Axial T2-Weighted Images on Spinal Stenosis: A Preliminary Study

• Jo GD
• Oh S
• Chai JW

• KMID: 2559679
• DOI: http://doi.org/10.13104/imri.2024.0013

Abstract

Purpose
To determine the effect of axial T2-weighted images (T2WIs) scanning order on the central canal, lateral recess, and related anatomical structures in the lumbar spine.
Materials and Methods
After Institutional Review Board approval and informed consent, 45 patients with low back pain (22 males and 23 females, aged between 20–83 years with median age of 60 years) underwent lumbar spine magnetic resonance examination in the supine position on a 1.5 tesla scanner. Axial T2WIs were acquired both before and after the sagittal scans (pre- and post-sagittal axial T2WIs). Two radiologists assessed the grades of the central canal and lateral recess stenosis (CCS and LRS) at the L3/4, L4/5, and L5/S1 levels. The cross-sectional areas of spinal canal (SCCSA), dural sac (DSCSA), free cerebrospinal fluid (FCSA), and ligamentum flavum (LFCSA) were measured twice from a single representative image at each disc level using a threshold-based semiautomated method. The effect of time on the CCS and LRS grades as well as cross-sectional areas was evaluated using a generalized estimating equation.
Results
Time had no significant effect on the CCS and LRS grades across the three disc levels (p = 0.178 for CCS, p = 0.383 for right LRS, p = 0.378 for left LRS). However, time significantly affected the DSCSA (p < 0.001), FCSA (p < 0.001), and LFCSA (p = 0.014), but not the SCCSA (p = 0.082). The DSCSA and FCSA were larger and the LFCSA was smaller on post-sagittal axial T2WIs than on pre-sagittal axial T2WIs; estimated differences were 2.9 mm 2 (2.3%) for DSCSA, 3.0 mm 2 (3.7%) for FCSA, and -2.4 mm 2 (-1.7%) for LFCSA.
Conclusion
The scanning order of axial T2WIs did not affect the CCS or LRS grades. However, the DSCSA, FCSA, and LFCSA in post-sagittal axial T2WIs showed significant differences compared to that of pre-sagittal axial T2WIs, although the relative percentage differences were less than 5%.

Keyword

Weight-bearing; Axial-loading; Scanning order; Spinal stenosis