4D Radial Acquisition Contrast-Enhanced MR Angiography and Intracranial Arteriovenous Malformations Quickly Approaching Digital Subtraction Angiography

Background and Purpose-The current gold standard for imaging intracranial AVMs involves catheter-based techniques, namely cerebral digital subtraction angiography (DSA). However, DSA presents some procedural risks to the patient. Unfortunately, AVM patients usually undergo multiple DSA exams throughout their diagnostic and therapeutic course, significantly increasing their procedural risk exposure. As such, high-quality noninvasive imaging is desired. We hypothesize that 4D radial acquisition contrast-enhanced MRA approximates the vascular architecture and hemodynamics of AVMs compared to conventional angiography. Methods-Thirteen consecutive AVM patients were assessed by 4D radial acquisition contrast-enhanced MRA and DSA. The 4D rCE-MRA images were independently assessed regarding the location, nidal size, Spetzler-Martin grade, and identification of arterial feeders, drainage pattern, and any other vascular anomalies. Results-4D rCE-MRA correctly depicted the size, venous drainage pattern, and prominent arterial feeders in all cases. Spetzler-Martin grade was correctly determined between reviewers and between the different imaging modalities in all cases except 1. The nidus size was in good correlation between the reviewers, where r = 0.99, P < 0.000001. There was very good agreement between reviewers regarding the individual scans (kappa = 0.63 to 1), whereas the agreement between the DSA and 4D rCE-MRA images was also good (kappa = 0.61 to 0.85). Conclusions-We have developed a 4D radial acquisition contrast-enhanced MRA sequence capable of imaging intracranial AVMs approximating that of DSA. Image analysis demonstrates equivalency in terms of grading AVMs using the Spetzler-Martin grading scale. This 4D rCE-MRA sequence has the potential to avoid some applications of DSA, thus saving patients from potential procedural risks. (Stroke. 2009; 40: 2749-2753.)