S Petteri Kauhanen1,2, Marja Hedman2, Elina Kariniemi3, Pekka Jaakkola4, Ritva Vanninen2, Petri Saari2, Timo Liimatainen2,5,6. 1. School of Medicine, Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland. 2. Department of Clinical Radiology, Kuopio University Hospital, Imaging Center, Kuopio, Finland. 3. Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Imaging Center, Kuopio, Finland. 4. Department of Heart and Thoracic Surgery, Kuopio University Hospital, Heart Center, Kuopio, Finland. 5. Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland. 6. Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
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. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:136-145.
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. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:136-145.
Authors: Pavlo Yevtushenko; Florian Hellmeier; Jan Bruening; Sarah Nordmeyer; Volkmar Falk; Christoph Knosalla; Marcus Kelm; Titus Kuehne; Leonid Goubergrits Journal: Biophys J Date: 2019-07-22 Impact factor: 4.033
Authors: Tarmo Korpela; S Petteri Kauhanen; Elina Kariniemi; Petri Saari; Timo Liimatainen; Pekka Jaakkola; Ritva Vanninen; Marja Hedman Journal: Eur J Cardiothorac Surg Date: 2022-01-24 Impact factor: 4.191
Authors: M J P van Hout; J F Juffermans; H J Lamb; E S J Kröner; P J van den Boogaard; M J Schalij; I A Dekkers; A J Scholte; J J Westenberg Journal: Int J Cardiol Heart Vasc Date: 2021-12-13
Authors: Miika Kiema; Jaakko K Sarin; S Petteri Kauhanen; Jari Torniainen; Hanna Matikka; Emma-Sofia Luoto; Pekka Jaakkola; Petri Saari; Timo Liimatainen; Ritva Vanninen; Seppo Ylä-Herttuala; Marja Hedman; Johanna P Laakkonen Journal: Front Physiol Date: 2022-07-07 Impact factor: 4.755
Authors: Charlotte Schubert; Jan Brüning; Leonid Goubergrits; Anja Hennemuth; Felix Berger; Titus Kühne; Marcus Kelm Journal: Sci Rep Date: 2020-11-03 Impact factor: 4.379