Which imaging modality is least useful for visualizing nerve roots in suspected radiculopathy?

Which imaging modality is least useful for visualizing nerve roots in suspected radiculopathy?

• A. X-ray
• B. MRI
• C. CT with contrast
• D. Ultrasound

Answer: (A)

Visualizing nerve roots requires imaging with strong soft-tissue contrast. X-ray mainly shows bone and alignment; it cannot reliably show nerve roots or the intervertebral discs and their relationship to the foramina, which is why it’s not useful for diagnosing radiculopathy. MRI, by contrast, provides high-detail images of the spinal cord, nerve roots, discs, and foraminal spaces, making it the best choice for identifying radicular compression. CT with contrast (often used as CT myelography) also delineates nerve roots and foraminal anatomy, especially when MRI isn’t possible. Ultrasound has limited ability to reach deep spinal structures like the nerve roots due to depth and bone shadowing, so it’s not suitable for visualizing spinal nerve roots.

Visualizing nerve roots requires imaging with strong soft-tissue contrast. X-ray mainly shows bone and alignment; it cannot reliably show nerve roots or the intervertebral discs and their relationship to the foramina, which is why it’s not useful for diagnosing radiculopathy. MRI, by contrast, provides high-detail images of the spinal cord, nerve roots, discs, and foraminal spaces, making it the best choice for identifying radicular compression. CT with contrast (often used as CT myelography) also delineates nerve roots and foraminal anatomy, especially when MRI isn’t possible. Ultrasound has limited ability to reach deep spinal structures like the nerve roots due to depth and bone shadowing, so it’s not suitable for visualizing spinal nerve roots.