Selected indications for and applications of magnetic resonance angiography in children.

The purpose of this study was to investigate the efficacy and practicality of magnetic resonance angiography (MRA) in evaluating pediatric cerebrovascular disorders. A retrospective evaluation was performed of MR angiograms in 20 pediatric patients with cerebrovascular pathology. When appropriate, comparisons were made with duplex ultrasonography or conventional catheter angiography. MRA accurately assessed the patency of carotid reanastomoses in 8 babies who had previously undergone extracorporeal membrane oxygenation (ECMO). In 6 patients with moyamoya syndrome, MRA accurately evaluated stenotic intracranial carotid and circle of Willis arteries and progressive enlargement of the superficial temporal and middle cerebral arteries after revascularization procedures, and thus obviated the need for sequential angiograms. Thrombi and emboli were identified in 4 of 5 patients with symptoms and imaging evidence of an acute stroke. Two-dimensional time-of-flight MR venograms, acquired in both axial and coronal planes, were useful for preoperative venous mapping in a patient with an occipital encephalocele and detecting venoocclusive disease. MRA provided diagnostically useful information in a spectrum of pediatric cerebrovascular disorders. It can be used as the initial vascular imaging modality for patients with imaging evidence of acute cerebrovascular event, to evaluate progression of chronic vasoocclusive disease, to evaluate vessel patency following intracranial revascularization surgery, and for visualization of the venous circulation.