Which imaging statement best confirms spinal stenosis?

• A. Plain X-ray demonstrates canal narrowing.
• B. MRI or CT demonstrates canal or foraminal narrowing.
• C. Ultrasound can visualize nerve compression.
• D. Bone scan shows canal narrowing.

Answer: (B)

Spinal stenosis is a narrowing of the spinal canal or foramina that can compress neural elements. To confirm this condition, you need imaging that directly shows the narrowed space around the nerves. MRI or CT provides detailed views of the canal and foramina, making it possible to see exactly where the narrowing occurs. MRI is especially useful because it shows soft tissues like the spinal cord, nerve roots, discs, and ligaments, so you can see compression from disc bulges or ligament thickening. CT offers excellent visualization of the bony structures and can reveal bony narrowing of the canal or foramina. Together, either modality demonstrating canal or foraminal narrowing gives a clear confirmation of stenosis.

Plain X-ray can hint at degenerative changes but doesn’t reliably show the actual narrowing affecting neural structures. Ultrasound isn’t capable of visualizing the spinal canal or nerve compression due to bone obstruction. Bone scans measure metabolic activity and bone turnover, not the space available for neural elements, so they don’t diagnose stenosis.