Use of magnetic resonance imaging for the evaluation of vascular malformations of the lower extremity

Vascular malformations are anatomically subdivided according to the predomi nant channel anomaly into either capillary, arterial, venous, lymphatic, or combinations. They can be further subdivided into high- or low-flow malfor mations. Any lesion that has an arterial component is considered a high-flo w malformation. Once the diagnosis of a vascular malformation is made, it i s of paramount importance to define not only the flow characteristics but a lso the full range of extension, because the prognosis and appropriate trea tment vary substantially for each type of anomaly. The two most useful noni nvasive imaging techniques for assessing vascular malformations are magneti c resonance imaging (MRI) and ultrasonography. The aim of this review is to give surgeons involved in treating patients with vascular malformations an opportunity to gain some background on MRI scans when assessing vascular m alformations. Although MRI is a powerful modality for assessing vascular ma lformations, we will also discuss some of the limitations of MRI We further suggest a diagnostic flow chart developed on the basis of MRI features des igned to help determine die composition of a vascular birthmark when interv ention is anticipated.