Preoperative and postoperative mapping of cerebrovascular reactivity in moyamoya disease by using blood oxygen level-dependent magnetic resonance imaging.
OBJECTIVE
The ability to map cerebrovascular reactivity (CVR) at the tissue level in patients with moyamoya disease could have considerable impact on patient management, especially in guiding surgical intervention and assessing the effectiveness of surgical revascularization. This paper introduces a new noninvasive magnetic resonance (MR) imaging-based method to map CVR. Preoperative and postoperative results are reported in three cases to demonstrate the efficacy of this technique in assessing vascular reserve at the microvascular level.


METHODS
Three patients with angiographically confirmed moyamoya disease were evaluated before and after surgical revascularization. Measurements of CVR were obtained by rapidly manipulating end-tidal PCO2 between hypercapnic and hypocapnic states during MR imaging. The CVR maps were then calculated by comparing the percentage of changes in MR signal with changes in end-tidal PCO2. Presurgical CVR maps showed distinct regions of positive and negative reactivity that correlated precisely with the vascular territories supplied by severely narrowed vessels. Postsurgical reactivity maps demonstrated improvement in the two patients with positive clinical outcome and no change in the patient in whom a failed superficial temporal artery-middle cerebral artery bypass was performed.


CONCLUSIONS
Magnetic imaging-based CVR mapping during rapid manipulation of end-tidal PCO2 is an exciting new method for determining the location and extent of abnormal vascular reactivity secondary to proximal large-vessel stenoses in moyamoya disease. Although the study group is small, there seems to be considerable potential for guiding preoperative decisions and monitoring efficacy of surgical revascularization.
Mikulis
David J
DJ
Department of Medical Imaging (Division of Neuroradiology), The Toronto Western Hospital of the University Health Network, University of Toronto, Toronto, Canada. mikulis@uhnres.utoronto.ca
Krolczyk
Gregory
G
Desal
Hubert
H
Logan
William
W
Deveber
Gabrielle
G
Dirks
Peter
P
Tymianski
Michael
M
Crawley
Adrian
A
Vesely
Alex
A
Kassner
Andrea
A
Preiss
David
D
Somogyi
Ron
R
Fisher
Joseph A
JA
D000328:Adult; D002245:Carbon Dioxide; D002548:Cerebral Revascularization / Q000379:methods*; D002561:Cerebrovascular Disorders / Q000209:etiology / Q000473:pathology*; D002648:Child; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009072:Moyamoya Disease / Q000503:physiopathology*; D011184:Postoperative Period; D011300:Preoperative Care; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity
D002245:Carbon Dioxide