Multimodality imaging of vascular anomalies.

Vascular malformations and hemangiomas are common in children but remain a source of confusion during diagnosis, in part because of the lack of a uniform terminology. With the existing treatments for hemangiomas and vascular malformations, it is important to make the correct diagnosis initially to prevent adverse physical and emotional sequelae in not only the child but also the family. The diagnosis of vascular malformations is made primarily by the clinician and based on the physical exam. Imaging is carried out using predominantly ultrasound (US) and magnetic resonance imaging (MRI), which are complementary modalities. In most cases of vascular anomalies, US is the first line of imaging as it is readily available, less expensive, lacks ionizing radiation and does not require sedation. MRI is also of great help for further characterizing the lesions. Conventional arteriography is reserved for cases that require therapeutic intervention, more commonly for arteriovenous malformations. Radiographs usually play no role in diagnosing vascular anomalies in children. In this article, the author describes the terminology and types of hemangiomas and vascular malformations and their clinical, histological features, as well as the imaging approach and appearance.