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
Visualizing and quantifying flow stasis in abdominal aortic aneurysms in men using 4D flow MRI
Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.ORCID iD: 0000-0001-9184-9234
Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.ORCID iD: 0000-0003-1942-7699
Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
Show others and affiliations
2019 (English)In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 57, p. 103-110Article in journal (Refereed) Published
Abstract [en]

Purpose: To examine methods for visualizing and quantifying flow stasis in abdominal aortic aneurysms (AAA) using 4D Flow MRI. Methods: Three methods were investigated: conventional volumetric residence time (VRT), mean velocity analysis (MVA), and particle travel distance analysis (TDA). First, ideal 4D Flow MRI data was generated using numerical simulations and used as a platform to explore the effects of noise and background phase-offset errors, both of which are common 4D Flow MRI artifacts. Error-free results were compared to noise or offset affected results using linear regression. Subsequently, 4D Flow MRI data for thirteen (13) subjects with AAA was acquired and used to compare the stasis quantification methods against conventional flow visualization. Results: VRT (R-2 = 0.69) was more sensitive to noise than MVA (R-2 = 0.98) and TDA (R-2 = 0.99) at typical noncontrast signal-to-noise ratio levels (SNR = 20). VRT (R-2 = 0.14) was more sensitive to background phase-offsets than MVA (R-2 = 0.99) and TDA (R-2 = 0.96) when considering a 95% effective background phase-offset correction. Qualitatively, TDA outperformed MVA (Wilcoxon p amp;lt; 0.005, mean score improvement 1.6/5), and had good agreement (median score 4/5) with flow visualizations. Conclusion: Flow stasis can be quantitatively assessed using 4D Flow MRI. While conventional residence time calculations fail due to error accumulation as a result of imperfect measured velocity fields, methods that do not require lengthy particle tracking perform better. MVA and TDA are less sensitive to measurement errors, and TDA generates results most similar to those obtained using conventional flow visualization.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE INC , 2019. Vol. 57, p. 103-110
Keywords [en]
Abdominal aortic aneurysm; Hemodynamics; 4D flow MRI; Flow stasis
National Category
Medical Laboratory and Measurements Technologies
Identifiers
URN: urn:nbn:se:liu:diva-154524DOI: 10.1016/j.mri.2018.11.003ISI: 000458096100012PubMedID: 30445146OAI: oai:DiVA.org:liu-154524DiVA, id: diva2:1290550
Available from: 2019-02-20 Created: 2019-02-20 Last updated: 2019-04-17
In thesis
1. Improving Assessments of Hemodynamics and Vascular Disease
Open this publication in new window or tab >>Improving Assessments of Hemodynamics and Vascular Disease
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Blood vessels are more than simple pipes, passively enabling blood to pass through them. Their form and function are dynamic, changing with both aging and disease. This process involves a feedback loop wherein changes to the shape of a blood vessel affect the hemodynamics, causing yet more structural adaptation. This feedback loop is driven in part by the hemodynamic forces generated by the blood flow, and the distribution and strength of these forces appear to play a role in the initiation, progression, severity, and the outcome of vascular diseases.

Magnetic Resonance Imaging (MRI) offers a unique platform for investigating both the form and function of the vascular system. The form of the vascular system can be examined using MR-based angiography, to generate detailed geometric analyses, or through quantitative techniques for measuring the composition of the vessel wall and atherosclerotic plaques. To complement these analyses, 4D Flow MRI can be used to quantify the functional aspect of the vascular system, by generating a full time-resolved three-dimensional velocity field that represents the blood flow.

This thesis aims to develop and evaluate new methods for assessing vascular disease using novel hemodynamic markers generated from 4D Flow MRI and quantitative MRI data towards the larger goal of a more comprehensive non-invasive examination oriented towards vascular disease. In Paper I, we developed and evaluated techniques to quantify flow stasis in abdominal aortic aneurysms to measure this under-explored aspect of aneurysmal hemodynamics. In Paper II, the distribution and intensity of turbulence in the aorta was quantified in both younger and older men to understand how aging changes this aspect of hemodynamics. A method to quantify the stresses generated by turbulence that act on the vessel wall was developed and evaluated using simulated flow data in Paper III, and in Paper V this method was utilized to examine the wall stresses of the carotid artery. The hemodynamics of vascular disease cannot be uncoupled from the anatomical changes the vessel wall undergoes, and therefore Paper IV developed and evaluated a semi-automatic method for quantifying several aspects of vessel wall composition. These developments, taken together, help generate more valuable information from imaging data, and can be pooled together with other methods to form a more comprehensive non-invasive examination for vascular disease.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2019. p. 64
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1675
National Category
Medical Image Processing Biomedical Laboratory Science/Technology
Identifiers
urn:nbn:se:liu:diva-156311 (URN)10.3384/diss.diva-156311 (DOI)9789176850985 (ISBN)
Public defence
2019-05-31, Hugo Theorell, Norra Entrén, Campus US, Linköping, 13:00 (English)
Opponent
Supervisors
Funder
Swedish Research Council, 2013-06077Swedish Research Council, 2017-03857Region Östergötland, LIO-752951
Available from: 2019-04-17 Created: 2019-04-12 Last updated: 2019-04-24Bibliographically approved

Open Access in DiVA

fulltext(1608 kB)52 downloads
File information
File name FULLTEXT01.pdfFile size 1608 kBChecksum SHA-512
025895f778312329a0ff7a43b9c77d3169eec331421f9c80bc43f286757b7ad0f1cffa1cf61d08ad9b2e047e7c7598505cbb7f90b8e6a5f1d96046b10a2cc3f8
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Ziegler, MagnusWelander, MartinLantz, JonasLindenberger, MarcusBjarnegård, NiclasKarlsson, MattsEbbers, TinoLänne, TosteDyverfeldt, Petter
By organisation
Division of Cardiovascular MedicineFaculty of Medicine and Health SciencesDepartment of Thoracic and Vascular SurgeryDepartment of Cardiology in LinköpingApplied Thermodynamics and Fluid MechanicsFaculty of Science & EngineeringCenter for Medical Image Science and Visualization (CMIV)Department of Clinical Physiology in Linköping
In the same journal
Magnetic Resonance Imaging
Medical Laboratory and Measurements Technologies

Search outside of DiVA

GoogleGoogle Scholar
Total: 52 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
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 83 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