CT Myelography More Useful for Patients With Multilevel Stenosis

CT myelography is more beneficial for patients with multilevel stenosis compared with patients with either no stenosis or single level stenosis, according to a new study.

Previous studies have shown that CT myelography is more sensitive in revealing stenosis compared to MRI (94.4% vs. 75.9%), but since it is a more invasive test, it should only be used on patients who would reap the most benefits, the researchers said.

They wrote, “The objective of this study was to identify subgroups of patients with lumbar stenosis for whom CT myelogram could be expected to provide additional information following an MRI scan.”

The retrospective study, “When Does CT-Myelography Add Value Beyond MRI for Lumbar Degenerative Disease?,” included consecutive series of patients with lumbar degenerative disease who were seen at a single institution. The main outcome measured was the degree of stenosis on MRI or CT-myelogram.

The study was published online on November 27, 2021, in The Spine Journal.

All the patients had a diagnosis of central stenosis, spondylolisthesis, or degenerative scoliosis. Each lumbar level was recorded as mild, moderate, or severe.

Overall, 269 patients were included in the study. Eighty percent or 207 of them had at least one level of moderate or severe central stenosis on MRI while 62 had mild or no stenosis on MRI.

Of the 207, 139 or 67% had multilevel stenosis and 68 or 33% had single level stenosis. CT myelogram was able to identify a greater proportion of additional stenotic levels in patients with multilevel stenosis compared to patients with single-level stenosis (58% vs. 40%; p = 0.018).

The researchers also found that CT myelogram was able to identify three additional stenotic levels in 62 patients with a clinical diagnosis of lumbar stenosis, but no moderate to severe stenosis on MRI (3/65, 5%; p = 0.836).

“CT Myelography is not as useful in providing additional information in patients with no stenosis or single level stenosis as compared to patients with multilevel stenosis,” the researchers wrote.

Study authors included Benjamin W. Weisenthal, M.D., Steven D. Glassman, M.D., Tino Mkorombindo, M.D., Lauren Nelson, M.D., and Leah Y. Carreon, M.D., all at the Norton Leatherman Spine Center in Louisville, Kentucky.