For suspected disc herniation with nerve involvement, which imaging modality is most informative?

• A. X-ray
• B. MRI
• C. Ultrasound
• D. CT without contrast

Answer: (B)

When evaluating suspected disc herniation with nerve involvement, the imaging choice that best reveals soft tissues and neural structures is MRI. X-ray mainly shows bones and alignment, offering little information about discs or nerve compression. Ultrasound isn’t reliable for visualizing the spine’s deep soft tissues, discs, or nerve roots. CT without contrast provides good bone detail but inferior soft tissue contrast compared with MRI, making it harder to delineate the herniated disc material and which nerve roots are affected. MRI, with its superior soft tissue contrast and multiplanar capability, directly shows the intervertebral discs, thecal sac, and nerve roots, allowing precise identification of the level and side of herniation and evidence of nerve compression or edema. If MRI isn’t possible, CT-based approaches can be used, but they don’t match MRI for soft tissue and neural assessment.