Published Online
on February 10, 2005

A more recent version of this article appeared on April 1, 2005

This Article Full Text (PDF) All Versions of this Article: 36/4/751    most recent 01.STR.0000157593.03470.3dv1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ziyeh, S. Articles by Speck, O. Search for Related Content PubMed PubMed Citation Articles by Ziyeh, S. Articles by Speck, O. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Blood and Blood Disorders Carotid Artery Disease MRI Scans Hazardous Substances DB CARBON DIOXIDE OXYGEN Related Collections Brain Circulation and Metabolism Carotid Stenosis Computerized tomography and Magnetic Resonance Imaging Doppler ultrasound, Transcranial Doppler etc.

Submitted on July 16, 2004
Revised on December 3, 2004
Accepted on December 21, 2004

Blood Oxygen Level-Dependent MRI of Cerebral CO₂ Reactivity in Severe Carotid Stenosis and Occlusion

Sargon Ziyeh MD^*; Jochen Rick; Matthias Reinhard MD; Andreas Hetzel MD; Irina Mader MD; and Oliver Speck PhD

From the Section of Neuroradiology (S.Z., I.M.), Neurocenter, Medical Physics (J.R., O.S.), Department of Radiology, Department of Neurology (M.R., A.H.), University Hospital of Freiburg D-79106 Freiburg, Germany.

^* To whom correspondence should be addressed. E-mail: ziyeh{at}nz.ukl.uni-freiburg.de.

Background and Purpose--Impaired cerebrovascular reserve capacity (CVC) is a risk factor for ischemic events in patients with high-grade carotid stenosis and occlusion. In this study, the CVC in response to a CO₂ challenge was evaluated with blood oxygen level-dependent (BOLD) MRI and the results compared with those of a transcranial Doppler CO₂ tests.

Methods--A T₂*-weighted single-shot multigradient echo-planar imaging sequence was used to determine cerebral CO₂ reactivity. T₂* values were calculated for each pixel at rest and during a challenge with 7% CO₂, and a reference function was fitted to the T₂* time courses. Whole-brain color-coded T₂* parameter maps were calculated and visually evaluated for regional differences. Additionally, a region-of-interest analysis was undertaken. Average values for T₂* normalized to changes in end-tidal PCO₂ were calculated. Results were correlated with a transcranial Doppler CO₂ tests in 20 patients with high-grade stenosis or occlusion of the carotid artery.

Results--Color parameter maps showed areas of decreased BOLD effect within the internal carotid artery territory in 12 of 13 hemispheres with impaired CVC in transcranial Doppler CO₂ test. Regional normalized T₂* was highly correlated with changes of middle cerebral artery blood flow velocity in transcranial Doppler CO₂ test. Normalized T₂* was significantly reduced in hemispheres with impaired CVC in transcranial Doppler (P<0.0001).

Conclusions--BOLD MRI can easily be included in routine MRI exams. The technique is robust and yields diagnostic information concerning the cerebrovascular reserve.

Key words: carotid stenosis • hemodynamics • magnetic resonance imaging • ultrasonography, Doppler, transcranial

This article has been cited by other articles:

				D. M. Mandell, J. S. Han, J. Poublanc, A. P. Crawley, A. Kassner, J. A. Fisher, and D. J. Mikulis Selective Reduction of Blood Flow to White Matter During Hypercapnia Corresponds With Leukoaraiosis Stroke, July 1, 2008; 39(7): 1993 - 1998. [Abstract] [Full Text] [PDF]

				D. M. Mandell, J. S. Han, J. Poublanc, A. P. Crawley, J. A. Stainsby, J. A. Fisher, and D. J. Mikulis Mapping Cerebrovascular Reactivity Using Blood Oxygen Level-Dependent MRI in Patients With Arterial Steno-occlusive Disease: Comparison With Arterial Spin Labeling MRI Stroke, July 1, 2008; 39(7): 2021 - 2028. [Abstract] [Full Text] [PDF]

				H. Barash, E. Gross, I. Matot, Y. Edrei, G. Tsarfaty, G. Spira, I. Vlodavsky, E. Galun, and R. Abramovitch Functional MR Imaging during Hypercapnia and Hyperoxia: Noninvasive Tool for Monitoring Changes in Liver Perfusion and Hemodynamics in a Rat Model Radiology, June 1, 2007; 243(3): 727 - 735. [Abstract] [Full Text] [PDF]