title: Relation between wall shear stress and carotid artery wall thickening MRI versus CFD.
abstract: Wall shear stress (WSS), a parameter associated with endothelial function, is calculated by computational fluid dynamics (CFD) or phase-contrast (PC) MRI measurements. Although CFD is common in WSS (WSSCFD) calculations, PC-MRI-based WSS (WSSMRI) is more favorable in population studies; since it is straightforward and less time consuming. However, it is not clear if WSSMRI and WSSCFD show similar associations with vascular pathology. Our aim was to test the associations between wall thickness (WT) of the carotid arteries and WSSMRI and WSSCFD. The subjects (n=14) with an asymptomatic carotid plaque who underwent MRI scans two times within 4 years of time were selected from the Rotterdam Study. We compared WSSCFD and WSSMRI at baseline and follow-up. Baseline WSSMRI and WSSCFD values were divided into 3 categories representing low, medium and high WSS tertiles. WT of each tertile was compared by a one-way ANOVA test. The WSSMRI and WSSCFD were 0.50±0.13Pa and 0.73±0.25Pa at baseline. Although WSSMRI was underestimated, a significant regression was found between WSSMRI and WSSCFD (r(2)=0.71). No significant difference was found between baseline and follow-up WSS by CFD and MRI-based calculations. The WT at baseline was 1.36±0.16mm and did not change over time. The WT was 1.55±0.21mm in low, 1.33±0.20mm in medium and 1.21±0.21mm in the high WSSMRI tertiles. Similarly, the WT was 1.49±0.21mm in low, 1.33±0.20mm in medium and 1.26±0.21mm in high WSSCFD tertiles. We found that WSSMRI and WSSCFD were inversely related with WT. WSSMRI and WSSCFD patterns were similar although MRI-based calculations underestimated WSS.
authors.affiliation: Erasmus MC, Biomedical Engineering Department, Rotterdam, The Netherlands.
authors.forename: Merih
authors.initials: M
authors.lastname: Cibis
authors.affiliation: AMC, Radiology Department, Amsterdam, The Netherlands.
authors.forename: Wouter V
authors.initials: WV
authors.lastname: Potters
authors.affiliation: Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: Mariana
authors.initials: M
authors.lastname: Selwaness
authors.affiliation: Erasmus MC, Biomedical Engineering Department, Rotterdam, The Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Gijsen
authors.affiliation: Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: Erasmus MC, Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Rotterdam, The Netherlands.
authors.forename: Andres M
authors.initials: AM
authors.lastname: Arias Lorza
authors.affiliation: Erasmus MC, Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Rotterdam, The Netherlands; Department of Computer Science, University of Copenhagen, Denmark.
authors.forename: Marleen
authors.initials: M
authors.lastname: de Bruijne
authors.affiliation: Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: Aad
authors.initials: A
authors.lastname: van der Lugt
authors.affiliation: AMC, Radiology Department, Amsterdam, The Netherlands.
authors.forename: Aart J
authors.initials: AJ
authors.lastname: Nederveen
authors.affiliation: Erasmus MC, Biomedical Engineering Department, Rotterdam, The Netherlands. Electronic address: j.wentzel@erasmusmc.nl.
authors.forename: Jolanda J
authors.initials: JJ
authors.lastname: Wentzel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000503:physiopathology*; D005260:Female; D006801:Humans; D057446:Hydrodynamics; D008279:Magnetic Resonance Imaging; D008297:Male; D058226:Plaque, Atherosclerotic / Q000503:physiopathology; D013314:Stress, Mechanical
keywords: CFD; Carotid arteries; Early wall thickening; Phase contrast MRI; Wall shear stress; Wall thickness