What is the basic normal arterial anatomy of the spinal cord?
The spinal cord is supplied by the anterior spinal artery (ASA) and the paired posterior spinal arteries (PSA). The ASA arises from the intradural segments of the vertebral arteries and supplies the anterior two thirds of the spinal cord. The ASA receives additional contribution from segmental arteries’ medullary feeders, which course superiorly and join the ASA, forming a classic “hairpin turn” configuration. Most medullary feeders arise from the lower thoracic region, where the dominant anterior segmental medullary feeder is called the artery of Adamkiewicz. This artery typically arises from a left posterior intercostal artery, most often from the T10 level, although it may arise anywhere from intercostal, subcostal, or lumbar arteries at the T7 to L4 vertebral levels and less frequently from the right side. The paired PSA are posteriorly located and supply the posterior one third of the spinal cord.
These typically arise from posterior inferior cerebellar arteries (PICA) or posterior rami of the vertebral arteries, and they receive additional contributions from medullary feeders arising from the posterior radicular arteries.