Interventional neuroradiology (INR) has evolved from a hybrid mixture of daring radiologists and iconoclastic neurosurgeons into a multidisciplinary specialty, which has become indispensable for cerebrovascular and neurological centers worldwide. This manuscript traces the origins of INR and describes its evolution to the present day. The focus will be on cerebrovascular disorders including aneurysms, stroke, brain arteriovenous malformations, dural arteriovenous fistulae, and atherosclerotic disease, both intra- and extracranial. Also discussed are cerebral vasospasm, venolymphatic malformations of the head and neck, tumor embolization, idiopathic intracranial hypertension, inferior petrosal venous sinus sampling for Cushing’s disease, and spinal interventions. Pediatric INR has not been included and deserves a separate, dedicated review.

Segmental duplications (also termed ‘fenestrations’) of the fetal anterior cerebral artery are a relatively rare anomaly. Their occurrence was studied in 200 fetuses at 20–40 wk gestational age. Duplications were found in 21 of the 200 fetuses, i.e. 10.5%. In 2 fetuses, i.e. 1%, the duplications were bilateral. In 1 case, i.e. 0.5%, 2 duplications were found on the left anterior cerebral artery. There were 15 segmental duplications on the left anterior cerebral artery, i.e. 62.5% of all duplications, and 9 on the right, i.e. 37.5%. The duplications were located in the distal part of the A1 segment in 45.7%, at the level of the anterior communicating artery (A1–A2) in 37.7%, and in the initial part of the A2 segment in 16.6%. The duplications had 4 different forms namely oviform, fissured, triangular and punctate.