Association Between Flow Acceleration in the Carotid Artery and Intracranial Aneurysms.
OBJECTIVES
In physiologic pulsatile flow, velocity acceleration is an independent factor determining wall shear stress experienced by the vascular endothelium. The purpose of this study was to evaluate Doppler indices of systolic velocity acceleration in extracranial cerebral vessels and the occurrence of intracranial aneurysms.


METHODS
We reviewed medical records and 3.0-T brain magnetic resonance imaging with 3-dimensional time-of-flight magnetic resonance angiography of 1323 adults who underwent health checkups from June 2006 to November 2011, in whom 53 intracranial aneurysms were identified in 45 patients. Doppler ultrasound parameters of the carotid and vertebral arteries were analyzed in these 45 patients with aneurysms and compared with another 45 control participants matched for age and sex. We defined the maximum systolic acceleration (ACCmax ) as the maximum slope of the early phase of systolic acceleration on the Doppler waveform and the maximum acceleration index (AImax ) as the ratio of the ACCmax and peak systolic velocity.


RESULTS
The Doppler analysis showed a significantly increased AImax and ACCmax in the common carotid artery (CCA), internal carotid artery, and vertebral artery in the aneurysm group. A cutoff 13.89 s-1 for the AImax of the CCA had sensitivity of 80% with a negative predictive value of 99% for intracranial aneurysms.


CONCLUSIONS
This study suggests that the AImax of the CCA with a cutoff of 13.89 s-1 may be an alternative to 3-dimensional time-of-flight magnetic resonance angiography or computed tomographic angiography as a screening tool for intracranial aneurysms. Further prospective studies are needed to validate the diagnostic performance and cost-effectiveness of these indices for screening.
['Chang|Chun-Wei|CW|', 'Wai|Yau-Yau|YY|', 'Lim|Siew-Na|SN|', 'Wu|Tony|T|']
D001783:Blood Flow Velocity D002339:Carotid Arteries D005260:Female D006801:Humans D002532:Intracranial Aneurysm D008297:Male D008875:Middle Aged D011446:Prospective Studies D015203:Reproducibility of Results D017585:Ultrasonography, Doppler, Transcranial D014711:Vertebral Artery
intracranial aneurysm aneurysm velocity acceleration carotid ultrasound vascular ultrasound