Magnetic resonance angiography (MRA) of ruptured cerebral aneurysm.

The purpose of this study was to evaluate the high resolution magnetic resonance angiography (MRA) as pre-operative angiography for the detection of ruptured cerebral aneurysms. MRA was performed on 1.5 tesla system using the 3-dimensional time of flight (3D-TOF) method. The field of view was 16 cm or 20 cm and matrix size was 192 x 256 or 256 x 512. Twenty patients with ruptured cerebral aneurysms and 35 cases of non-ruptured aneurysms (incidental aneurysm) examined by both conventional angiography and MRA were included in this study. All the ruptured aneurysms were operated on based on the information obtained from conventional angiography and MRA. Aneurysms smaller than 3 mm in size were difficult to visualize on MRA. However, most ruptured aneurysms were clearly visualized because they were generally larger than 3 mm. The image quality of MRA was satisfactory for planning surgery. Screening for non-ruptured cerebral aneurysms using MRA is controversial. However, in ruptured aneurysms larger than 3 mm in size, MRA clearly revealed the aneurysm, and MRA findings were informative enough to plan surgery. It is concluded that this noninvasive examination can be selected as a first-choice examination especially in cases of ruptured aneurysm.