What are the indications for a computed tomography (CT) myelogram?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: November 16, 2025 • View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

CT Myelogram Indications

CT myelography is indicated when MRI is contraindicated, nondiagnostic, or when specific anatomic detail of the spinal canal and neural structures is needed for surgical planning, particularly in patients with metallic hardware or complex spinal pathology. 1

Primary Indications

When MRI Cannot Be Performed or Is Inadequate

  • Patients with MRI-incompatible implanted devices (pacemakers, certain neurostimulators) who require detailed evaluation of spinal canal patency and neural compression 1
  • Significant metallic artifact from surgical hardware that degrades MRI quality, making CT myelography occasionally more accurate for diagnosing nerve root compression in the lateral recess 1
  • Contraindications to MRI including certain metallic implants, severe claustrophobia, or body habitus limitations 2

Surgical and Treatment Planning

  • Preoperative planning for spinal stenosis when detailed assessment of thecal sac patency, subarticular recesses, and neural foramina is needed 1
  • Radiation therapy treatment planning where precise anatomic delineation is critical 2
  • Multilevel central spinal stenosis when dynamic information during the myelogram procedure may be helpful 3

Specific Diagnostic Scenarios

  • Suspected arachnoid cyst, arachnoid web, or ventral cord herniation when MRI findings are equivocal or require confirmation 1
  • Positional myelopathy where flexion/extension CT myelography can demonstrate dynamic compression 1
  • Brachial plexus injury where CT myelography is recognized as the study of choice 2
  • CSF leak localization where CT myelography remains the gold standard 2

Anatomic Region-Specific Indications

Cervical Spine

  • Equivocal MRI findings in cervical radiculopathy when clinical symptoms strongly suggest nerve root compression 1
  • Suspected spinal cord or nerve root injury in trauma when MRI cannot be performed, though MRI remains superior for soft-tissue pathology 1
  • Foraminal stenosis and bony lesions when detailed osseous anatomy is needed 1

Thoracic Spine

  • Thoracic myelopathy or radiculopathy to differentiate ventral cord herniation from dorsal arachnoid web or cyst 1
  • Presurgical planning due to high anatomic detail and resolution of spinal canal contents 1

Lumbar Spine

  • Cauda equina syndrome for surgical planning when MRI shows significant stenosis requiring intervention 1
  • Post-surgical patients with new or progressive symptoms when hardware artifact limits MRI interpretation 1
  • Multilevel lumbar stenosis where CT myelography identifies additional stenotic levels in 58% of cases compared to 40% in single-level disease 4

Clinical Context and Limitations

When CT Myelography Adds Value

  • Multilevel stenosis on MRI: CT myelography provides additional diagnostic information in patients with multilevel stenosis (58% show additional levels) compared to single-level stenosis (40%) 4
  • Complementary to MRI: Occasionally more accurate for lateral recess nerve root compression diagnosis 1

When CT Myelography Does NOT Add Value

  • No stenosis on MRI: In patients with clinical lumbar stenosis but no moderate-to-severe stenosis on MRI, CT myelography identifies additional stenotic levels in only 5% of cases 4
  • Initial evaluation of most spinal pathology: MRI remains superior for soft-tissue contrast, cord pathology, and non-invasive assessment 1, 5

Important Caveats

  • Invasive procedure requiring lumbar puncture with intrathecal contrast injection, carrying procedural risks including headache, infection, and rare complications like cerebral edema 1, 6
  • Radiation exposure from CT imaging 2
  • Inferior to MRI for cord contusion, hemorrhage, and postganglionic nerve root injuries in trauma settings 1
  • Cannot replace MRI for initial evaluation of myelopathy, as MRI provides superior visualization of marrow, spinal cord intrinsic pathology, and soft tissues 1, 5

FDA-Approved Contrast Agents

  • Iopamidol (Omnipaque) is FDA-approved for intrathecal administration in myelography (lumbar, thoracic, cervical), CT cisternography, and ventriculography in adults, and for thoraco-lumbar myelography in children over 2 years 7

References

1
Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

2
Research

Myelography: modern technique and indications.

Handbook of clinical neurology, 2016

3
Research

Imaging evaluation of patients with spinal deformity.

The Orthopedic clinics of North America, 1994

4
Research

When does CT myelography add value beyond MRI for lumbar degenerative disease?

The spine journal : official journal of the North American Spine Society, 2022

5
Guideline

Imaging Modalities for Spinal Stenosis

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Related Questions

What is the difference between a Computed Tomography (CT) myelogram and a Magnetic Resonance Imaging (MRI) of the lumbar spine?
What is the most likely diagnostic test for a patient presenting with worsening bilateral lower extremity paresthesias and weakness, fatigue, and occasional diplopia?
What is the procedure for a myelography?
What is the best imaging modality for a patient with a palpable soft lump over the thoracic central spine who experiences numbness in the wrist when leaning on it?
What is a myelogram and when is it recommended?
What is the preferred medication, cyproheptadine (antihistamine) or olanzapine (atypical antipsychotic), for treating Avoidant/Restrictive Food Intake Disorder (ARFID)?
What is the role of clopidogrel (antiplatelet agent) in the management of stable angina?
What are the causes of metabolic acidosis?
How effective is the Conner scale (Conners Adult ADHD Rating Scales) when combined with cognitive objective digitized tools for diagnosing Attention Deficit Hyperactivity Disorder (ADHD)?
What is the treatment for esophageal varices?
What is the recommended usage and treatment duration for Hydrocortisone (corticosteroid) 1% cream for mild to moderate skin conditions?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question