Spinal Arterial Supply¶
Definition¶
The spinal cord receives its arterial blood supply from three longitudinal arteries — one anterior and two posterior spinal arteries — which are reinforced at multiple levels by segmental radiculomedullary arteries. The largest and most clinically important of these feeders is the artery of Adamkiewicz (also known as great anterior radiculomedullary artery or arteria radicularis anterior magna), which supplies the anterior spinal artery in the lower thoracic and lumbar cord.
Anatomy¶
Longitudinal Arteries¶
- Anterior spinal artery (ASA) — a single midline vessel running in the anterior median fissure of the cord; supplies the anterior two-thirds of the cord (motor tracts, spinothalamic tracts, and the anterior horns)
- Posterior spinal arteries (PSA) — paired arteries running along the posterolateral surface of the cord near the dorsal root entry zones; supply the posterior one-third (dorsal columns and posterior horns)
Segmental Supply¶
The longitudinal arteries cannot sustain the entire cord alone and are reinforced by segmental feeders:
- Radicular arteries — enter the neural foramen at each level; most supply only the nerve root and do not reach the cord
- Radiculomedullary arteries — a smaller number (6–8 anterior, 10–20 posterior) that are large enough to reach and reinforce the longitudinal spinal arteries
- Segmental arteries — arise from the aorta (intercostal and lumbar arteries), vertebral arteries, ascending cervical, and deep cervical arteries depending on the spinal level
Artery of Adamkiewicz¶
- The dominant anterior radiculomedullary artery in most individuals
- Typically arises from the left side in ~75% of cases
- Enters the spinal canal most commonly between T9 and T12 (range T8–L2)
- Has a characteristic "hairpin turn" as it ascends along the nerve root before turning caudally to join the anterior spinal artery
- Supplies the anterior spinal artery feeding the lumbar enlargement (lower extremity motor function and bowel/bladder control)
Watershed Zones¶
- The mid-thoracic cord (T4–T8) lies between the cervical and Adamkiewicz territories and is a vascular watershed zone
- This region is most vulnerable to ischemia during hypotension, aortic surgery, or interruption of segmental feeders
Clinical Pearl
The artery of Adamkiewicz is critically important during aortic surgery, thoracolumbar spine surgery, and embolization procedures. Interruption of this vessel can result in anterior cord syndrome — paraplegia with loss of pain/temperature sensation but preservation of proprioception and vibration (posterior column sparing). Preoperative identification by CTA or MRA is increasingly performed before thoracoabdominal aortic repair. Imaging findings of anterior cord syndrome include punctate hyperintense T2 signal appearing as two bright-dots on axial imaging resulting in the so called "owl eye appearance "
Imaging Findings¶
CTA¶
- High-resolution CTA with multiplanar reformats can identify the artery of Adamkiewicz in approximately 70–90% of cases
- Look for a small vessel entering a neural foramen at the left lower thoracic level with the characteristic "hairpin" configuration
- Best performed with thin-section bolus-tracked acquisition
MRA¶
- Time-resolved MRA can demonstrate the anterior spinal artery and major radiculomedullary feeders
- Lower spatial resolution than CTA but avoids radiation
- Useful for preoperative mapping before thoracoabdominal aortic procedures
Spinal Angiography¶
- The gold standard for identifying spinal vascular anatomy
- Selective catheterization of segmental arteries demonstrates the feeder vessels, longitudinal arteries, and venous drainage
- Primarily used for evaluating spinal vascular malformations (AVMs, AVFs) and preoperative mapping for complex surgery
MRI¶
| Finding | Appearance |
|---|---|
| Anterior spinal artery | Small flow void on axial T2 in the anterior median fissure |
| Cord infarction | T2 hyperintensity within the cord, often in an "owl eye" pattern on axial images (bilateral anterior horn involvement) |
| Restricted diffusion | Bright on DWI in acute infarction |
Key MRI Finding
Spinal cord infarction from anterior spinal artery occlusion produces a characteristic "owl eyes" sign on axial T2 — bilateral symmetric hyperintensity in the anterior horns of the gray matter. On sagittal images, the infarction appears as a "pencil-like" longitudinal T2 hyperintensity spanning multiple segments, typically in the anterior cord.
Key Points¶
- The anterior spinal artery supplies the anterior two-thirds of the cord; posterior spinal arteries supply the posterior one-third
- The artery of Adamkiewicz is the dominant anterior feeder, typically arising from the left between T9 and T12
- The mid-thoracic cord (T4–T8) is a watershed zone vulnerable to ischemia
- Anterior cord infarction produces the "owl eyes" sign on axial T2 MRI
- CTA and MRA can identify the artery of Adamkiewicz preoperatively
- Spinal angiography is the gold standard for vascular mapping
References¶
- Lindeire S, Hauser JM. Anatomy, Back, Artery of Adamkiewicz. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532971/
- Hasan S, Arain A. Neuroanatomy, Spinal Cord Arteries. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539889/
- Munakomi S, Launico MV. Anatomy, Anterior Spinal Artery. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532963/
- Sandoval JI, De Jesus O. Anterior Spinal Artery Syndrome. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560731/
- Taterra D, Skinningsrud B, Pękala PA, Hsieh WC, Cirocchi R, Walocha JA, Tubbs RS, Tomaszewski KA, Henry BM. Artery of Adamkiewicz: a meta-analysis of anatomical characteristics. Neuroradiology. 2019;61(8):869-880. Available from: https://pubmed.ncbi.nlm.nih.gov/31030251/
- Kalogeropoulos P, Tsouknidas I, Tasis N, Papoutsis K, Athanasopoulos A, Livanos K, Piagkou M, Troupis T, Filippou DK. The Artery of Adamkiewicz: Anatomy and Considerations in Spine Surgery - A Review of the Literature. J Long Term Eff Med Implants. 2022;32(2):81-86. Available from: https://pubmed.ncbi.nlm.nih.gov/35695630/