Vascular anomalies: nomenclature, classification, and imaging algorithms

There is a lot of ambiguity in the usage of correct terminology in the description of vascular malformations and tumors. Hemangioma and arteriovenous malformation (AVM) are the most commonly used terms and are the mostly incorrectly used as well! The aim of this review article was to lay out the correct nomenclature and describe the correct usage for the physicians and radiologists involved in diagnosing and managing these lesions. We describe the various classification systems which have been devised to define the multiple entities included under vascular anomalies. The latest classification system that should be adhered to is per the International Society for the Study of Vascular Anomalies, approved at the 20th ISSVA Workshop held in Melbourne in April 2014, last revised in May 2018. The main features of the latest revision have been highlighted. This classification, however, does not list the diagnostic clinico-radiological features for each entity. In addition, guidelines regarding the appropriate use of available imaging modalities are lacking in the literature. We, hereby, aim to address these pertinent issues in this review article.