Magnetic resonance digital subtraction angiography (MRDSA) in the assessment of abnormalities associated with cerebral aneurysm

Our goal was to compare the value of magnetic resonance digital subtraction angiography (MRDSA) with magnetic resonance angiography (MRA) in detecting abnormalities associated with cerebral aneurysm. This study included three patients with unruptured cerebral aneurysms, 60 with clipped aneurysm, and eight with extracranial-intracranial (EC-IC) bypass to treat aneurysms. MRDSA was obtained using a 3D fast field-echo sequence in combination with a parallel imaging technique, and was compared with 3D time-of-flight MRA. A temporal resolution of 0.8 s/frame could be achieved. For unruptured aneurysms, better images were obtained with MRDSA than with MRA in two out of the three patients. In patients with clipped aneurysms, 660 vessel segments were evaluated (11 segments per patient in the 60 patients); MRDSA provided significantly better images than MRA (20.2% versus 9.7%). In the EC-IC bypass patients, MRDSA was better than or comparable with MRA in seven of the eight patients. MRDSA may become a useful tool for evaluating diseases associated with cerebral aneurysm. (author)