title: Evaluation of aortic geometries created by magnetic resonance imaging data in healthy volunteers.
abstract: BACKGROUND
  The development of atherosclerotic plaques has been associated with the patterns of wall shear stress (WSS). However, much is still uncertain with the methods used to calculate WSS. Correct vessel geometries are mandatory to get reliable estimations, and the purpose of this study was to evaluate an in vivo method for creating aortic 3D geometry in human based on data from magnetic resonance imaging (MRI) with ultrasound as reference.
  
  
  METHODS
  The aortas of ten healthy men, 23·4 ± 1·6 years of age, were examined with a 1·5 T MRI system using a 3D gadolinium-enhanced gradient-echo sequence. Three-dimensional geometries were created using manual segmentation of images. Lumen diameters (LD) were measured in the abdominal aorta (AA) and the thoracic aorta (TA) with non-invasive B-mode ultrasound as a reference.
  
  
  RESULTS
  The anteroposterior diameter of the AA was 13·6 ± 1·1 mm for the MRI and 13·8 ± 1·3 mm for the ultrasound (NS). Intraobserver variability (CV) for MRI and ultrasound was <0·92% and <0·40%, respectively. Interobserver variability for MRI and ultrasound was 0·96% and 0·56%, respectively. The diameter of the TA was 19·2 ± 1·4 mm for the MRI, and the intraobserver variability (CV) was <0·78% and interobserver variability (CV) was 0·92%.
  
  
  CONCLUSIONS
  Specific arterial geometries can be constructed with a high degree of accuracy using MRI. This indicates that the MRI geometries may be used to create realistic and correct geometries in the calculation of WSS in the aorta of human.
authors: Department of Medicine and Health Sciences Department of Mechanical Engineering Center for Medical Image Science and Visualization (CMIV), Linköping University, Sweden.
authors: Daniel
authors: D
authors: Modin
authors: Johan
authors: J
authors: Renner
authors: Roland
authors: R
authors: Gårdhagen
authors: Tino
authors: T
authors: Ebbers
authors: Toste
authors: T
authors: Länne
authors: Matts
authors: M
authors: Karlsson
mesh_terms: D000328:Adult; D001012:Aorta, Abdominal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D001013:Aorta, Thoracic / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003287:Contrast Media; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography; D008297:Male; D015588:Observer Variation; D012016:Reference Values; D015203:Reproducibility of Results; D013548:Sweden; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA