Which imaging technique uses contrast medium to visualize the spinal cord and study distortions caused by tumors, cysts, or herniated disks?

• A. Myelography
• B. MRI
• C. MUGA scan
• D. Ophthalmoscopy

Answer: (A)

Visualizing the spinal canal with contrast to reveal distortions from space-occupying lesions is achieved with myelography. This approach injects contrast into the subarachnoid space and then uses X-ray or CT to outline the spinal cord and nerve roots. Distortions from tumors, cysts, or herniated disks appear as indentations, displacement, or abnormal contouring of the thecal sac on the images, making the extent of compression visible. Although MRI is now the preferred method for many spinal issues due to being noninvasive and providing excellent soft-tissue detail, the distinctive feature here is the intrathecal contrast outlining the spinal canal to show compressive changes. The other options relate to imaging different organs or use different principles (cardiac function assessment, retinal examination) and do not specifically describe contrast outlining of the spinal cord.