title: A novel method for assessing arterial endothelial function using phase contrast magnetic resonance imaging: vasoconstriction during reduced shear.
abstract: We investigated whether endothelial-dependent arterial constriction during reduced shear can be measured using phase contrast magnetic resonance imaging (PCMRI). A cross-section of the femoral artery was acquired during a 5-minute distal occlusion in 33 subjects. Systolic shear rate and radius were measured from the velocity profile via a best-fit parabola. Systolic shear rate decreased immediately after cuff inflation (404 +/- 78 to 233 +/- 75 sec(-1) p < .0001). Radius decreased at 2 min into inflation (3.52 +/- .41 to 3.43 +/- .42 mm, p < .0001). In conclusion, arterial constriction during reduced flow can be measured using PCMRI. This new method may add important information toward a comprehensive evaluation of endothelial function.
authors.affiliation: Division of Cardiology, Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA. hsilber@jhmi.edu
authors.forename: Harry A
authors.initials: HA
authors.lastname: Silber
authors.forename: Pamela
authors.initials: P
authors.lastname: Ouyang
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: Sandeep N
authors.initials: SN
authors.lastname: Gupta
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Foo
authors.forename: Joao A C
authors.initials: JA
authors.lastname: Lima
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D005263:Femoral Artery / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results; D012107:Research Design; D012737:Sex Factors; D033081:Shear Strength; D013599:Systole; D014661:Vasoconstriction