PMC3157482_01
Preoperative sagittal T1-weighted MR images (A) and sagittal T2-weighted MR images (B) demonstrating spinal canal stenosis and some traction of the spinal cord above the L1-2 level (arrow) and loose cauda equina below that level (turquoise brackets). Sedated imaging of the lumbar spine performed with the patient in a supine position 3 months postoperatively: sagittal images, T1-weighted (C), T2-weighted (D), proton density (E) and STIR (F), showing no tension on the spinal cord above L1-2, but tethering of the nerve roots between the two stenotic levels, L1-2 and L4-5 (turquoise brackets). Magnification of the axial T2-weighted MR images (G) show the tip of the conus medullaris (arrow) at the mid to upper L1 vertebral body cranial to the L1-2 stenosis. Axial images (H & I) show the tip of the conus medullaris (arrow in H) and caudally, distal nerve roots with the terminal filum (arrow in I) visible still cranial to the L1-2 stenosis.
nihms316459f1.jpg
PMC3157482_01_nihms316459f1.jpg
F1
On lumbrosacral MRI, he had significant spinal stenosis, most severe at L4-5, and less severe at L3-4 and L5-S1 (Figure 1A, 1B and Figure 2). The study showed increased stenosis at L1-2 and L4-5 with tethering of the nerve roots between these two levels of stenosis (Figure 1C-F), which was different from the preoperative imaging of the lumbosacral spine performed three months earlier in which the nerve roots were dispersed and scattered between L2 to S1 and taut above the level of stenosis at L1-2 (Figure 1A & B). The conus medullaris appeared to terminate at the level of the mid to upper L1 vertebral body just above the level of the L1-2 spinal stenosis (Figure 1.
Axial T2 weighted images (TE/TR = 115/8600 ms) obtained during sedation with the patient in a supine position. Left image demonstrates severe spinal canal stenosis at L1-2 with minimal surrounding CSF. Middle image shows relatively normal non-stenotic spinal canal at L2-3 with hyperintense CSF surrounding the cauda equina. Right image shows moderate spinal stenosis at L4-5, with residual AP diameter of the thecal sac approximately 9.0 mm.
nihms316459f2.jpg
PMC3157482_01_nihms316459f2.jpg
F2
On lumbrosacral MRI, he had significant spinal stenosis, most severe at L4-5, and less severe at L3-4 and L5-S1 (Figure 1A, 1B and Figure 2).