Spinal Angiography¶
Definition¶
Spinal angiography (spinal digital subtraction angiography, or DSA) is a catheter-based, minimally invasive imaging procedure that provides the most detailed evaluation of the spinal vascular anatomy. It is the gold standard for diagnosing and characterizing spinal vascular malformations and is used to plan endovascular or surgical treatment.
Technique¶
Procedure¶
- Arterial access: femoral artery puncture under local anesthesia (occasionally radial access)
- Selective catheterization: a catheter is advanced into each segmental artery (intercostal, lumbar, subclavian branches) that may supply the spinal cord
- Contrast injection: iodinated contrast is injected into each vessel while rapid-sequence fluoroscopic images are obtained
- Digital subtraction: pre-contrast images are subtracted from post-contrast images to isolate the vascular structures
- Systematic survey: both sides at every level from the vertebral arteries to the internal iliac arteries may need to be catheterized for a complete study
Key Technical Points¶
- A complete spinal angiogram may require catheterization of 20–40 individual segmental arteries
- Procedure time: 2–6 hours depending on complexity
- Typically performed under moderate sedation or general anesthesia
- Real-time imaging allows assessment of flow dynamics, feeding arteries, nidus, and draining veins
Indications¶
- Spinal vascular malformations:
- Spinal dural arteriovenous fistula (SDAVF) — the most common spinal vascular malformation
- Spinal arteriovenous malformation (AVM) — intramedullary, perimedullary, or extradural
- Perimedullary arteriovenous fistula
- Pre-surgical vascular mapping:
- Identification of the artery of Adamkiewicz before thoracoabdominal aortic surgery
- Planning for complex spinal tumor resection (embolization of hypervascular tumors)
- Spinal hemorrhage: evaluation when MRI suggests vascular etiology (subarachnoid or intramedullary hemorrhage of unknown cause)
- Embolization: therapeutic embolization of spinal AVMs, AVFs, and hypervascular tumors is performed via the same catheter access
Imaging Findings¶
| Finding | Appearance |
|---|---|
| Spinal dural AVF | Early opacification of a perimedullary vein from a dural arterial feeder; slow-flow lesion |
| Spinal AVM | Nidus of abnormal vessels within or on the cord; high-flow with early draining veins |
| Artery of Adamkiewicz | Characteristic "hairpin turn" — ascending course along nerve root then descending to join ASA |
| Normal segmental artery | Intercostal or lumbar artery with small radicular branches |
| Hypervascular tumor | Tumor blush with prominent arterial feeders (e.g., renal cell metastasis, hemangioblastoma) |
Clinical Pearl
Spinal dural arteriovenous fistula (SDAVF) is the most common spinal vascular malformation and a treatable cause of progressive myelopathy. It typically presents in older men with slowly progressive lower extremity weakness, sensory changes, and bladder dysfunction. MRI shows T2 cord signal change and perimedullary flow voids. Spinal angiography is essential for diagnosis — it identifies the fistula point and the specific feeding artery, which guides surgical disconnection or endovascular embolization.
Complications¶
- Spinal cord ischemia — the most serious risk; can occur if a radiculomedullary artery supplying the cord is occluded by the catheter or embolization material
- Arterial injury — dissection, thrombosis, or perforation
- Contrast reaction — allergic reaction to iodinated contrast
- Nephrotoxicity — contrast-induced kidney injury
- Access site complications — hematoma, pseudoaneurysm
- Radiation exposure — prolonged fluoroscopy results in significant radiation dose to the patient and operator
Key Points¶
- Spinal angiography is the gold standard for evaluating spinal vascular malformations
- It involves selective catheterization of segmental arteries to map the spinal blood supply
- SDAVF is the most common spinal vascular malformation — a treatable cause of myelopathy
- Pre-surgical mapping of the artery of Adamkiewicz is critical before aortic surgery
- Therapeutic embolization can be performed through the same catheter access
- Spinal cord ischemia is the most serious potential complication
References¶
- Nijenhuis RJ, Mull M, Wilmink JT, Thron AK, Backes WH. MR angiography of the great anterior radiculomedullary artery (Adamkiewicz artery) validated by digital subtraction angiography. AJNR Am J Neuroradiol. 2006;27(7):1565-72. Available from: https://www.ajnr.org/content/27/7/1565
- Saraf-Lavi E, Bowen BC, Quencer RM, Sklar EML, Holz A, Falcone S, et al. Detection of spinal dural arteriovenous fistulae with MR imaging and contrast-enhanced MR angiography: sensitivity, specificity, and prediction of vertebral level. AJNR Am J Neuroradiol. 2002;23(5):858-67. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7974721/
- Nair S, Gobin YP, Leng LZ, Marcus JD, Bilsky M, Laufer I, et al. Preoperative embolization of hypervascular thoracic, lumbar, and sacral spinal column tumors: technique and outcomes from a single center. Interv Neuroradiol. 2013;19(3):377-85. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC3806015/
- Rangel-Castilla L, Shah AH, Klucznik RP, Diaz OM. Preoperative Onyx embolization of hypervascular head, neck, and spinal tumors: experience with 100 consecutive cases from a single tertiary center. J Neurointerv Surg. 2014;6(1):51-6. Available from: https://pubmed.ncbi.nlm.nih.gov/23268473/
- Gaillard F, et al. Spinal arteriovenous malformations. Radiopaedia.org. Available from: https://radiopaedia.org/articles/spinal-arteriovenous-malformations
- Gaillard F, et al. Spinal dural arteriovenous fistula. Radiopaedia.org. Available from: https://radiopaedia.org/articles/spinal-dural-arteriovenous-fistula