title: Phase-contrast magnetic resonance imaging for the evaluation of wall shear stress in the common carotid artery of a spontaneously hypertensive rat model at 7T: Location-specific change, regional distribution along the vascular circumference, and reproducibility analysis.
abstract: To measure wall shear stress (WSS) in the common carotid arteries (CCA) of a spontaneously hypertensive rat (SHR) model and a normotensive Wistar Kyoto rat (WKY) model by 2D phase-contrast magnetic resonance imaging (PC-MRI).
  
  
  
  PC-MRI was performed on 7 SHR and 7 WKY at ages of 4 and 7months at a 7T scanner. Images in the middle CCA (CCAmid) and in the bifurcation of CCA (CCAbifur) were acquired. The WSS values for differentiating characteristics between two models were calculated. Further, its location-specific change, regional distribution along the CCA circumference, and the reproducibility were evaluated.
  
  
  
  In the 4-month-old rats, SHR showed lower temporal averaged WSS (WSSavg) and peak systolic WSS (WSSs) in the CCAbifur in comparison with WKY (WSSavg: 0.95±0.18 vs. 1.30±0.36N/m(2) (P<0.01); WSSs: 1.68±0.70 vs. 3.22±2.49N/m(2) (P<0.05)). We observed the same trends in the 7-month-old rats. In the SHR model, the WSSavg was lower in the CCAbifur than in the CCAmid. The regional distribution of WSSavg along the circumference of CCA showed lower values in WKY, particularly in posterior segments of CCAbifur. The intra-observer, intra-scan and inter-scan reproducibility was acceptable and the disagreements were ranged from -0.05 to 0.06N/m(2).
  
  
  
  This study evaluated WSS in SHR and WKY models by 2D PC-MRI. High reproducibility analyses further indicated the reliability of measurements of WSS in the CCA of SHR and WKY models using PC-MRI at 7T.
authors.affiliation: Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan, ROC; Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, ROC.
authors.forename: Shin-Lei
authors.initials: SL
authors.lastname: Peng
authors.affiliation: Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan, ROC.
authors.forename: Fu-Nien
authors.initials: FN
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan, ROC.
authors.forename: Tao-Chieh
authors.initials: TC
authors.lastname: Yang
authors.affiliation: Department of Anesthesiology, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Jee-Ching
authors.initials: JC
authors.lastname: Hsu
authors.affiliation: Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital, Taoyuan, Taiwan, ROC.
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Wu
authors.affiliation: Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan, ROC. Electronic address: hhpeng@mx.nthu.edu.tw.
authors.forename: Hsu-Hsia
authors.initials: HH
authors.lastname: Peng
mesh_terms: D000818:Animals; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004195:Disease Models, Animal; D006973:Hypertension / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D015203:Reproducibility of Results
keywords: Flow measurement; Phase-contrast magnetic resonance imaging; Spontaneously hypertensive rat; Wall shear stress