A CT scan of the spine is an imaging test that uses X-rays and computer processing to produce detailed cross-sectional pictures of the vertebrae, spinal canal, discs and surrounding tissues. It helps identify fractures, herniated discs, spinal stenosis, infections or tumors and guides surgical planning. The procedure is quick and noninvasive, may use contrast dye, and involves exposure to ionizing radiation.

There’s no fixed, universal limit on CT scans per person. Use is individualized: clinicians order CTs only when benefits outweigh small added cancer risk from cumulative ionizing radiation. Alternatives (ultrasound, MRI) and dose-reduction techniques are preferred when suitable. For most people a single or occasional CT poses low risk; repeated high-dose CTs are avoided and tracked to minimize lifetime exposure.

Costs vary widely. In India a spinal CT typically costs about ₹1,500–₹10,000. In the UK it’s free on the NHS for eligible patients; private clinics charge roughly £150–£700. In the US billed amounts commonly range from about $300–$3,000. Final price depends on contrast use, number of levels scanned, facility type, and insurance or public coverage.

The adult human spine has five regions: cervical—7 vertebrae (C1–C7); thoracic—12 vertebrae (T1–T12); lumbar—5 vertebrae (L1–L5); sacral—5 vertebrae fused into the sacrum (S1–S5); and coccygeal—typically 3–5 vertebrae fused into the coccyx (commonly 4). Total vertebrae usually number 33, though individual variation can make the count about 32–34.

A CT scan can detect structural causes of nerve damage—fractures, bone spurs, disc fragments, tumors or bony spinal narrowing—and with CT myelography can show nerve-root compression. However, CT cannot directly visualize microscopic nerve fiber injury or many soft-tissue changes; MRI is generally better for imaging nerves, discs and spinal cord. Clinical exam and electrodiagnostic tests often confirm nerve function loss.

MRI is generally better for spine soft tissues — discs, spinal cord, nerve roots, infection and inflammation — and avoids radiation. CT provides superior bone detail, detects fractures, and is faster or used when MRI is contraindicated. Choice depends on the clinical question: use MRI for nerve or disc problems and CT for trauma, complex bone assessment, or when MRI can’t be performed.