Brief Description of ISSVA Classification for Radiologists.

Ongoing discovery regarding the origin and treatment of vascular anomalies requires standardized nomenclature which itself must undergo iterative updating. This article introduces the 2018 International Society for the Study of Vascular Anomalies (ISSVA) classification, emphasizing the biologic basis of vascular anomalies, summarizing the key features of commonly encountered entities, and serving as a foundation for subsequent articles presented herein. Vascular tumors are discussed to highlight their distinction from vascular malformations which will receive greater attention with respect to management and technical considerations within the issue.