CT Lumbar Spine (Routine / Degenerative)
CTNo contrastSpine
Indications
- Lumbar radiculopathy/low back pain with suspected degenerative disease when MRI contraindicated
- Spinal/foraminal stenosis, spondylolysis (pars defect), spondylolisthesis
- Post-operative fusion/hardware evaluation
- Osseous lesion characterization, pre-procedural planning
Patient prep
- No prep or contrast for routine degenerative study
- Supine with knees flexed over bolster to reduce lordosis when tolerated
- Remove dense objects from field; immobilize
Contrast
None / non-contrast
Technique
- Supine; helical volume from T12 through S1 (include conus region and sacrum)
- 120 kV; mAs per scanner with AEC; iterative reconstruction
- Reconstruct thin (0.625-1.25 mm) bone and soft-tissue kernels
- Reformat sagittal and coronal; angled axials through each disc space are common for degenerative reads
- Quiet breathing; no breath-hold
Series / Sequences
| # | Series / Sequence | Plane | Thickness | Notes |
|---|---|---|---|---|
| 1 | Axial bone | axial | 0.625-1.25 mm | Facets, pars, foramina; sharp kernel |
| 2 | Axial soft tissue (disc-angled) | axial | 2-3 mm | Angled parallel to each disc; disc herniation, canal |
| 3 | Sagittal reformat (bone & soft tissue) | sagittal | 1-2 mm | Alignment, listhesis, foraminal stenosis |
| 4 | Coronal reformat (bone) | coronal | 1-2 mm | Scoliosis, transitional anatomy |
Key points
- Note transitional lumbosacral anatomy and provide consistent level numbering
- MRI is first-line for radiculopathy; CT excels at bony stenosis, pars defects (oblique/sagittal reformats), facet arthrosis, and post-fusion assessment
- CT myelography alternative when MRI contraindicated
- Report disc bulge/herniation, central canal and lateral recess/foraminal stenosis, and spondylolisthesis grade
References
• ACR–ASNR–ASSR–SPR Practice Parameter for the Performance of CT of the Spine
• ACR Appropriateness Criteria: Low Back Pain
• Radiopaedia: CT lumbar spine (protocol) link
• RadioGraphics: CT and MRI of the Degenerative Lumbar Spine
• ACR Appropriateness Criteria: Low Back Pain
• Radiopaedia: CT lumbar spine (protocol) link
• RadioGraphics: CT and MRI of the Degenerative Lumbar Spine
Source: Researched — verify against your institution
Reference template — verify and adapt to your scanner, vendor and institution before clinical use. Not a substitute for clinical judgment.