Abstract
Objective: Unruptured cerebral aneurysms were studied by ECG-triggered MR angiogram (MRA). Changes in the diameter of aneurysms and morphological changes in portions of the aneurysmal walls were examined. Methods: Twenty-nine patients (14males; 15 females) with 31 aneurysms were examined by ECG-triggered MRA between April 2004 and December 2005. Regarding the distribution of unruptured aneurysms,13 were in the middle cerebral artery area,11 in the internal carotid artery area,6 in the anterior communicating/ anterior cerebral artery area and 1 in the vertebro-basilar artery area. Changes in the aneurysms were thought to be significant if the ratio of the longitudinal diameter of the aneurysm during the systolic phase to that in the diastolic phase was larger than those ratios in the normal arteries around the aneurysm and if there were prominent morphological changes in the aneurysmal walls during the systolic phase compared with findings during the diastolic phase, such as bulging or dilation of portions of the aneurysmal wall. Results: 6 of 31 aneurysms(19%)demonstrated significant changes in diameter, and 13 of 31 aneurysms(42%)showed morphological changes. The aneurysms showing changes in diameter were often located in the internal carotid artery area. The aneurysms showed morphological changes were located in the anterior communicating artery and middle cerebral artery area. Conclusions: We speculated that aneurysms showing morphological changes during the systolic phase on ECG-triggered MRA would have a greater risk of rupture than aneurysms that did not show such changes.
