University of Oulu

Kauhanen, S. P., Hedman, M., Kariniemi, E., Jaakkola, P., Vanninen, R., Saari, P., & Liimatainen, T. (2019). Aortic dilatation associates with flow displacement and increased circumferential wall shear stress in patients without aortic stenosis: A prospective clinical study. Journal of Magnetic Resonance Imaging, 50(1), 136–145. https://doi.org/10.1002/jmri.26655

Aortic dilatation associates with flow displacement and increased circumferential wall shear stress in patients without aortic stenosis : a prospective clinical study

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Author: Kauhanen, S. Petteri1,2; Hedman, Marja2; Kariniemi, Elina3;
Organizations: 1School of Medicine, Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
2Department of Clinical Radiology, Kuopio University Hospital, Imaging Center, Kuopio, Finland
3Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital,Imaging Center, Kuopio, Finland
4Department of Heart and Thoracic Surgery, Kuopio University Hospital, Heart Center, Kuopio, Finland
5Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
6Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
Format: article
Version: accepted version
Access: embargoed
Persistent link: http://urn.fi/urn:nbn:fi-fe2019091227996
Language: English
Published: John Wiley & Sons, 2019
Publish Date: 2020-01-18
Description:

Abstract

Background: The relationship between blood flow characteristics and ascending aortic (AA) dilatation has not been studied in patients with a tricuspid aortic valve (TAV) without aortic stenosis.

Purpose: To evaluate whether 4D flow characteristics determined in MRI are related to AA dilatation by comparing dilated AA and nondilated AA subjects with TAV.

Study Type: Prospective.

Population: Twenty patients with dilated AA and 20 age‐matched patients with nondilated AA.

Field Strength/Sequence: 1.5T/4D flow, 2D flow, and anatomic images.

Assessment: Altogether, 16 different 4D flow parameters were assessed in 10 planes in the thoracic aorta. Intra‐ and interobserver reproducibility were analyzed.

Statistical Tests: Independent t‐test for normally distributed and the Mann–Whitney test for skewed distributed parameters were used. A paired‐samples t‐test was used to compare 2D and 4D flow parameters. Intraclass correlation coefficient (ICC) was used in intra‐ and interobserver reproducibility analysis.

Results: Aortic flow was displaced from the centerline of the aorta in the proximal and tubular planes. Flow displacement (FD) was greatest in the proximal plane of AA and was higher in dilated AA (4.5%, range 3.0–5.8%) than in nondilated AA (2.0%, 1.0–3.0%, P < 0.001). Total wall shear stress (WSS) values were 1.3 ± 0.4 times higher on the displaced side than on the opposite side of the aorta (P < 0.01). The circumferential WSS (WSSC) ratio to total WSS was greater in dilated AA, being 0.48 ± 0.11 vs. 0.32 ± 0.09 in the inner curvature of the proximal AA (P < 0.001) and 0.37 ± 0.11 vs. 0.26 ± 0.07 in the whole aortic ring in the distal AA (P < 0.001). Depending on 4D flow parameters, reproducibility varied from excellent (ICC = 0.923) to very low (ICC = 0.204).

Data Conclusion: The present study demonstrates that 4D flow measurements help to visualize the pathological flow patterns related to aortic dilatation. Flow displacement and an increased WSSc/WSS ratio are significantly associated with AA dilatation.

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Series: Journal of magnetic resonance imaging
ISSN: 1053-1807
ISSN-E: 1522-2586
ISSN-L: 1053-1807
Volume: 50
Issue: 1
Pages: 136 - 145
DOI: 10.1002/jmri.26655
OADOI: https://oadoi.org/10.1002/jmri.26655
Type of Publication: A1 Journal article – refereed
Field of Science: 3121 General medicine, internal medicine and other clinical medicine
Subjects:
Funding: Contract grant sponsor: Personal grant from the will of OivaVaittinen and the Rättimäki Cardiovascular Society (to S.P.K.).
Copyright information: © 2019 International Society for Magnetic Resonance in Medicine. This is the peer reviewed version of the following article: Kauhanen, S. P., Hedman, M., Kariniemi, E., Jaakkola, P., Vanninen, R., Saari, P., & Liimatainen, T. (2019). Aortic dilatation associates with flow displacement and increased circumferential wall shear stress in patients without aortic stenosis: A prospective clinical study. Journal of Magnetic Resonance Imaging, 50(1), 136–145. https://doi.org/10.1002/jmri.26655, which has been published in final form at https://doi.org/10.1002/jmri.26655. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.