Noninvasive follow-up of GDC-treated saccular aneurysms by MR angiography

The aim of this study was to determine sensitivity and specificity of magne tic resonance angiography (MRA) for the assessment of durable occlusion of intracranial aneurysms with Guglielmi detachable coils (GDC) and to point o ut the influence of MRA results in re-intervention strategies. Forty-five p atients with 54 aneurysms that were previously treated by endovascular occl usion with GDC were selected for this study. All patients underwent digital subtraction angiography (DSA) and MRA examinations on the same day. The ti me-of-flight MRA studies were performed on a 1-T scanner. The MRA images we re first read by radiologists who were not aware of the DSA results. In a s econd consensus reading by the neuroradiologists who had performed all inte rventional procedures of this series, the decision was made as to whether r e-treatment was necessary. The distribution of aneurysm sizes, configuratio ns and treatment results were sufficient for an unbiased evaluation. The fi rst blinded evaluation revealed a sensitivity of 71% and a specificity of 9 5% for MRA assessment of aneurysm reperfusion. In the second consensus read ing, the sensitivity increased to 92% and the specificity was 98%. The blin ded reading indicates that MRA is a useful adjunct to DSA for the assessmen t of durable results after endovascular treatment of intracranial aneurysms . In the consensus reading it became obvious that sensitivity and specifici ty of MRA can be increased to 92 and 98%, respectively, if the results were evaluated by experienced neuroradiologists, including prior knowledge of a ll other examinations. We have already increased the follow-up intervals fo r DSA and use MRA intermittently, based on these results.