A CT scan of the lumbar spine gives detailed cross-sectional images of the vertebrae and surrounding structures. It shows bony anatomy, fractures, alignment or spondylolisthesis, osteophytes and facet-joint degeneration, disc calcification or bulging, spinal-canal and foraminal narrowing, tumors or infections, and postsurgical hardware position. It’s especially useful for bone detail; MRI better shows soft tissues and nerve roots.

A CT scan of the lumbar spine usually takes about 10–20 minutes for the actual imaging. Expect the whole appointment — registration, changing, positioning and any IV contrast setup — to take about 20–60 minutes. If contrast or extra images are required, the visit may be longer. Results are reviewed by a radiologist and reported afterward.

Before a lumbar CT, confirm whether IV contrast will be used (contrast may require blood tests, fasting 4–6 hours, and holding metformin). Inform staff of allergies, kidney disease, or pregnancy. Bring ID and prior imaging, arrive early, and remove jewelry, metal and tight clothing. Expect an IV line, lie very still during scanning, and follow instructions to hydrate after contrast.

CT of the lumbar spine is usually performed without intravenous contrast when assessing bone injury, fractures, or degenerative disease. Contrast is reserved for evaluating suspected infection, tumor, epidural abscess, or when better soft‑tissue or vascular detail is required. Choice depends on the clinical question, prior imaging, and patient factors (eg, kidney function); your clinician or radiologist will decide.

A CT scan can reveal bony causes of spinal nerve impingement—herniated bone, fractures, osteophytes and canal narrowing—but it does not directly image nerve tissue or show nerve injury. MRI is the preferred test for visualizing discs, spinal cord and nerve roots. CT myelography and electrodiagnostic studies (EMG/NCS) may be used when MRI is contraindicated or to assess nerve function.

For a lumbar CT, wear loose, comfortable clothing without metal fasteners—avoid zippers, buttons, underwire bras, belts and metal jewelry. You may be asked to change into a hospital gown. Remove piercings, hearing aids and removable dental work before the scan. If contrast dye is planned, follow any fasting or medication instructions from your provider. Bring underwear without metal if you prefer not to change.