Assessment of intracranial blood flow velocities using a computer controlled vasoactive stimulus: A comparison between phase contrast magnetic resonance angiography and transcranial doppler ultrasonography
Article first published online: 12 NOV 2012
Copyright © 2013 Wiley Periodicals, Inc., a Wiley company
Journal of Magnetic Resonance Imaging
Volume 38, Issue 3, pages 733–738, September 2013
How to Cite
Leung, J., Behpour, A., Sokol, N., Mohanta, A. and Kassner, A. (2013), Assessment of intracranial blood flow velocities using a computer controlled vasoactive stimulus: A comparison between phase contrast magnetic resonance angiography and transcranial doppler ultrasonography. J. Magn. Reson. Imaging, 38: 733–738. doi: 10.1002/jmri.23911
- Issue published online: 30 AUG 2013
- Article first published online: 12 NOV 2012
- Manuscript Accepted: 25 SEP 2012
- Manuscript Received: 11 JAN 2012
- Canadian Institutes of Health Research. Grant Number: FRN: 94383, 111113
- middle cerebral artery;
- transcranial Doppler;
- phase contrast;
- blood flow velocity;
- cerebrovascular reactivity;
- CO2 challenge
To compare measurements of blood flow velocity (BFV) and BFV changes in the middle cerebral arteries (MCA) acquired from phase contrast magnetic resonance angiography (PCMRA) and transcranial Doppler ultrasound (TCD) during controlled manipulation of end-tidal partial pressure of carbon dioxide (PetCO2).
Materials and Methods:
In vivo TCD and PCMRA velocity data from the M1 segment in the MCA of nine healthy adult volunteers were acquired during precise targeting of PetCO2 induced by a computer-controlled gas delivery system. Doppler spectra and phase contrast data were processed into time-averaged peak-velocity (TAPV) values for comparison. Changes in velocity between baseline and hypercapnia were analyzed in terms of velocity-based cerebrovascular reactivity (CVR).
Good correlation between the pairs of velocity measurements acquired from the two modalities were found (ρ = 0.81), but Bland–Altman analysis indicates a significant bias error. There was relatively weak agreement between the pairs of computed CVR values (ρ = −0.26).
Under precise PetCO2 control, PCMRA proves to be more consistent than TCD. Despite issues with variability, TCD is qualitatively comparable to PCMRA measures of velocity in the MCA. However, PCMRA velocity results are better suited for analyses that require quantitative values, such as CVR. J. Magn. Reson. Imaging 2013;38:733–738. © 2012 Wiley Periodicals, Inc.