Purpose: To report a case of unilateral segmental agenesis of the vertebral artery (VA). Methods: We describe the angiographic and MRI features of a segmental VA agenesis (C2 segment). Results: VA agenesis is caused by the absence of the anastomotic connection normally linking two adjacent intersegmental arteries; in the reported observation, a paravertebral extraforaminal anastomosis replaced the C2 segment normally joining the 1st and 2nd cervical intersegmental arteries through the C2 transverse foramen. Conclusion: We present an observation of segmental VA agenesis. This variant is consistent with the developmental history of the VA. It appears exceptional but is more likely underappreciated.
- Anatomical variation
- Vertebral artery
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Radiology Nuclear Medicine and imaging