Which imaging will show the disc bulge?

• A. X-rays
• B. CT scan
• C. Electromyography and Nerve Conduction Velocity
• D. Magnetic Resonance Imaging

Answer: (D)

Soft-tissue visualization of the spine is what lets us see a disc bulge. Intervertebral discs and surrounding nerve structures are soft tissue, and magnetic resonance imaging provides the best contrast for these tissues. MRI can clearly show the shape and extent of the disc, including a broad-based bulge extending beyond the normal disc margins and any potential contact with nerve roots in the canal. X-rays mainly show bone and alignment and miss soft-tissue detail, while CT offers good bone detail but less soft-tissue contrast than MRI. Electromyography and nerve conduction studies assess nerve function, not anatomy, so they don’t reveal the disc contour. Therefore, MRI is the imaging modality best suited to visualize a disc bulge.