Magnetic resonance of vascular anomalies.

More than half of the patients with vascular anomalies referred to the Vascular Anomalies Clinic at Children's Hospital, Boston, have been misdiagnosed. A major consequence of misdiagnosis is inappropriate treatment, including deferral of necessary treatment and inappropriate use of pharmacotherapy, radiation, surgery, and embolotherapy. Hemangiomas and vascular malformations are distinct categories with completely different biologic and clinical behavior, therapeutic requirements, and imaging features. This article reviews the biologic classification of vascular anomalies and corresponding MR imaging features, and presents a simplified guide to diagnosis.