Echocardiogram-Gated Computed Tomographic and Magnetic Resonance Angiographies for the Detection of Pulsatile Expansion at the Intracranial Arterial Bifurcation

Abstract

Objective: To identify the pulsatile small vascular lesion by echocardiogram (ECG)-gated computed tomographic (CT) and magnetic resonance (MR) angiographies. Methods: Seven patients who exhibited small evagination at the cerebral artery bifurcations on 3-dimensional (3D) time-of-flight MR angiogram were enrolled. They were examined by conventional/ECG-gated CT angiogram (n = 6) and ECG-gated MR angiogram (n = 5). Echocardiogram-gated MR angiogram was performed with 3D time of flight, triggered after each time window. From ECG-gated CT and MR angiograms, consecutive 10-phase images within a single cardiac cycle were obtained. Results: The pulsatile change of evagination was demonstrated on both ECG-gated CT angiogram (5 of 6 patients) and ECG-gated MR angiogram (all 5 patients). Flattening of the evagination during the diastolic phase was observed in 4 of 6 ECG-gated CT angiograms and 3 of 5 ECG-gated MR angiograms. Of note was a patient with a tiny evagination (<2 x 1 mm); pulsatile change was demonstrated only by ECG-gated MR angiogram. Conclusion: The pulsatile expansion of evagination at the cerebral artery bifurcation can be demonstrated on ECG-gated CT/MR angiograms.