liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Evaluation of Aortic Geometries created by MRI Data in Man
Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences.
Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, The Institute of Technology.
Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, The Institute of Technology.
Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Clinical Physiology in Linköping.ORCID iD: 0000-0003-1395-8296
Show others and affiliations
2011 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 31, no 6, 485-491 p.Article in journal (Refereed) Published
Abstract [en]

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 man based on data from magnetic resonance imaging (MRI) with ultrasound as reference.

Methods: The aortas of ten healthy males, 23.4 ± 1.6 years of age, were examined with MRI, and 3D geometries were created with manual segmentation of the 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 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) were <0.78% and interobserver variability (CV) were 0.92%.

Conclusion: Specific arterial geometries can be constructed with a high degree of accuracy using MRI. This indicate that the MRI geometries may be used to create realistic and correct geometries in the calculation of WSS in the aorta of man.

Place, publisher, year, edition, pages
Wiley-Blackwell , 2011. Vol. 31, no 6, 485-491 p.
Keyword [en]
human aorta, lumen diameter, magnetic resonance imaging, manual segmentation, ultrasound
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-65905DOI: 10.1111/j.1475-097X.2011.01035.xISI: 000296198100011OAI: oai:DiVA.org:liu-65905DiVA: diva2:400267
Available from: 2011-02-25 Created: 2011-02-25 Last updated: 2017-12-11Bibliographically approved
In thesis
1. Towards Subject Specific Aortic Wall Shear Stress: a combined CFD and MRI approach
Open this publication in new window or tab >>Towards Subject Specific Aortic Wall Shear Stress: a combined CFD and MRI approach
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The cardiovascular system is an important part of the human body since it transports both energy and oxygen to all cells throughout the body. Diseases in this system are often dangerous and cardiovascular diseases are the number one killer in the western world. Common cardiovascular diseases are heart attack and stroke, which origins from obstructed blood flow. It is generally important to understand the causes for these cardiovascular diseases. The main causes for these diseases are atherosclerosis development in the arteries (hardening and abnormal growth). This transform of the arterial wall is believed to be influenced by the mechanical load from the flowing blood on the artery and especially the tangential force the wall shear stress. To retrieve wall shear stress information in arteries invivo is highly interesting due to the coupling to atherosclerosis and indeed a challenge. The goal of this thesis is to develop, describe and evaluate an in-vivo method for subject specific wall shear stress estimations in the human aorta, the largest artery in the human body. The method uses an image based computational fluid dynamics approach in order to estimate the wall shear stress. To retrieve in-vivo geometrical descriptions of the aorta magnetic resonance imaging capabilities is used which creates image material describing the subject specific geometry of the aorta. Magnetic resonance imaging is also used to retrieve subject specific blood velocity information in the aorta. Both aortic geometry and velocity is gained at the same time. Thereafter the image material is interpreted using level-set segmentation in order to get a three-dimensional description of the aorta. Computational fluid dynamics simulations is applied on the subject specific aorta in order to calculate time resolved wall shear stress distribution at the entire aortic wall included in the actual model.

This work shows that it is possible to estimate subject specific wall shear stress in the human aorta. The results from a group of healthy volunteers revealed that the arterial geometry is very subject specific and the different wall shear stress distributions have general similarities but the level and local distribution are clearly different. Sensitivity (on wall shear stress) to image modality, the different segmentation methods and different inlet velocity profiles have been tested, which resulted in these general conclusions:

  • The aortic diameter from magnetic resonance imaging became similar to the reference diameter measurement method.
  • The fast semi-automatic level-set segmentation method gave similar geometry and wall shear stress results when compared to a reference segmentation method.
  • Wall shear stress distribution became different when comparing a simplified uniform velocity profile inlet boundary condition with a measured velocity profile.

The method proposed in this thesis has the possibility to produce subject specific wall shear stress distribution in the human aorta. The method can be used for further medical research regarding atherosclerosis development and has the possibility for usage in clinical work.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2011. 40 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1360
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:liu:diva-65910 (URN)978-91-7393-244-8 (ISBN)
Public defence
2011-04-12, ACAS, hus A, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2011-02-25 Created: 2011-02-25 Last updated: 2017-03-27Bibliographically approved

Open Access in DiVA

fulltext(253 kB)406 downloads
File information
File name FULLTEXT01.pdfFile size 253 kBChecksum SHA-512
def014e659c73f1d729e3f016ae2599defb72ba07449798913a53027cbb54df6ec85bacf54db5ce1c55e762b2a673d6f083db5c4b1d239ecf3e0837e0dd2a189
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Authority records BETA

Modin, DanielRenner, JohanGårdhagen, RolandEbbers, TinoLänne, TosteKarlsson, Matts

Search in DiVA

By author/editor
Modin, DanielRenner, JohanGårdhagen, RolandEbbers, TinoLänne, TosteKarlsson, Matts
By organisation
Clinical PhysiologyFaculty of Health SciencesApplied Thermodynamics and Fluid MechanicsCenter for Medical Image Science and Visualization (CMIV)The Institute of TechnologyDepartment of Clinical Physiology in LinköpingPhysiologyDepartment of Thoracic and Vascular Surgery
In the same journal
Clinical Physiology and Functional Imaging
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 406 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 364 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf