Blood oxygen level-dependent MRI of tissue oxygenation. Relation to endothelium-dependent and endothelium-independent blood flow changes

Item Type:	Article
Title:	Blood oxygen level-dependent MRI of tissue oxygenation. Relation to endothelium-dependent and endothelium-independent blood flow changes
Creators Name:	Utz, W. and Jordan, J. and Niendorf, T. and Stoffels, M. and Luft, F.C. and Dietz, R. and Friedrich, M.G.
Abstract:	OBJECTIVES: The contribution of endothelial function to tissue oxygenation is not well understood. Muscle blood oxygen level-dependent MRI (BOLD MRI) provides data largely dependent on hemoglobin (Hb) oxygenation. We used BOLD MRI to assess endothelium-dependent signal intensity (SI) changes. METHODS AND RESULTS: We investigated mean BOLD SI changes in the forearm musculature using a gradient-echo technique at 1.5 T in 9 healthy subjects who underwent a protocol of repeated acetylcholine infusions at 2 different doses (16 and 64 microg/min) and N(G)-monomethyl-L-arginine (L-NMMA; 5 mg/min) into the brachial artery. Sodium nitroprusside was used as a control substance. For additional correlation with standard methods, the same protocol was repeated, and forearm blood flow was measured by strain gauge plethysmography. We obtained a significant increase in BOLD SI during acetylcholine infusion (64 microg/min) and a significant decrease for L-NMMA infusion (P<0.005 for both). BOLD SI showed a different kinetic signal than did blood flow, particularly after intermittent ischemia and at high flow rates. CONCLUSIONS: In standard endothelial function tests, BOLD MRI detects a dissociation of tissue Hb oxygenation from blood flow. BOLD MRI may be a useful adjunct in assessing endothelial function.
Keywords:	Magnetic Resonance Imaging, Endothelial Function, BOLD, Plethysmography
Source:	Arteriosclerosis Thrombosis and Vascular Biology
ISSN:	1079-5642
Publisher:	American Heart Association
Volume:	25
Number:	7
Page Range:	1408-1413
Date:	July 2005
Official Publication:	https://doi.org/10.1161/01.ATV.0000170131.13683.d7
PubMed:	View item in PubMed

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