Purpose: To characterize the non-laminar flow dynamics and resultant decreased wall shear stress (WSS) and high oscillatory shear index (OSI) of the infrarenal abdominal aortic dilatation, cardiac phase-resolved 3D phase-contrast MRI (4D-flow MRI) was performed.
Methods: The prospective single-arm study was approved by the Institutional Review Board and included 18 subjects (median 67.5 years) with the dilated infrarenal aorta (median diameter 35 mm). 4D-flow MRI was conducted on a 1.5T MRI system. On 3D streamline images, laminar and non-laminar (i.e., vortex or helical) flow patterns were visually assessed both for the dilated aorta and for the undilated upstream aorta. Cardiac phase-resolved flow velocities, WSS and OSI, were also measured for the dilated aorta and the upstream undilated aorta.
Results: Non-laminar flow represented by vortex or helical flow was more frequent and overt in the dilated aorta than in the undilated upstream aorta (P < 0.0156) with a very good interobserver agreement (weighted kappa: 0.82-1.0). The WSS was lower, and the OSI was higher on the dilated aortic wall compared with the proximal undilated segments. In mid-systole, mean spatially-averaged WSS was 0.20 ± 0.016 Pa for the dilated aorta vs. 0.68 ± 0.071 Pa for undilated upstream aorta (P < 0.0001), and OSI on the dilated aortic wall was 0.093 ± 0.010 vs. 0.041 ± 0.0089 (P = 0.013). The maximum values and the amplitudes of the WSS at the dilated aorta were inversely proportional to the ratio of dilated/undilated aortic diameter (r = -0.694, P = 0.0014).
Conclusion: 4D-flow can characterize abnormal non-laminar flow dynamics within the dilated aorta in vivo. The wall of the infrarenal aortic dilatation is continuously and increasingly affected by atherogenic stimuli due to the flow disturbances represented by vortex or helical flow, which is reflected by lower WSS and higher OSI.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7553816 | PMC |
| http://dx.doi.org/10.2463/mrms.mp.2019-0188 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Distribution and Maturity of Medial Collagen Fibers in Thoracoabdominal Post-Dissection Aortic Aneurysms: A Comparative Study of Marfan and Non-Marfan Patients.
Int J Mol Sci
December 2024
Department of Vascular Surgery, RWTH Aachen University Hospital, 52074 Aachen, Germany.
Thoracoabdominal aortic aneurysms (TAAAs) are rare but serious conditions characterized by dilation of the aorta characterized by remodeling of the vessel wall, with changes in the elastin and collagen content. Individuals with Marfan syndrome have a genetic predisposition for elastic fiber fragmentation and elastin degradation and are prone to early aneurysm formation and progression. Our objective was to analyze the medial collagen characteristics through histological, polarized light microscopy, and electron microscopy methods across the thoracic and abdominal aorta in twenty-five patients undergoing open surgical repair, including nine with Marfan syndrome.
View Article and Find Full Text PDFUnderstanding the Mechanisms of Main Bronchial Compression in Patients with Intracardiac Anomalies.
Ann Thorac Surg Short Rep
September 2024
Department of Pediatric Cardiovascular Surgery, Kanazawa Medical University, Ishikawaken, Japan.
Background: The study focuses on vascular compression of the main bronchus in the aortopulmonary space, examining potential contributors within the same axial plane. Its goal is to uncover mechanisms of bronchial compression in patients with intracardiac anomalies and review surgical outcomes, aiming to enhance future results.
Methods: The morphology and topology of structures within the axial plane of the aortopulmonary space were objectively analyzed, including the sternum, ascending aorta, heart, pulmonary artery, descending aorta, and other relevant elements.
Aortopathy in repaired tetralogy of Fallot and David procedure.
Cardiovasc Diagn Ther
December 2024
Department of Cardiology, St. Luke's International Hospital, Tokyo, Japan.
Tetralogy of Fallot (TOF) is a condition that often leads to long-term enlargement of the aortic root in after surgery. The aortic dilation is believed to be caused by histological abnormalities of the aortic media and the hemodynamic characteristics of increased aortic flow, compared to pulmonary flow. Severe cyanosis, severe right ventricular outflow tract (RVOT) obstruction, older age at repair, a larger aortic size at the time of repair, and a history of an aortopulmonary shunt parameters related to long-standing volume overload of the aortic root were the reported risk factors.
View Article and Find Full Text PDFZ-score evaluation and inferences for management of aortopathy patients.
Cardiol Young
January 2025
Department of Pediatrics, Oregon Health and Science University, Portland, OR, USA.
Echocardiographic Z-score models play a crucial role in defining cardiac pathology in paediatric patients. There are multiple models that practitioners utilize in the United States without guiding principles to standardize their use. Discrepant interpretations can occur depending on the model chosen, even if standardized Z-score cutoffs are applied.
View Article and Find Full Text PDFTopsy-Turvy Heart: Exceedingly Rare Congenital Rotational Heart Disease With Large Aorticopulmonary Window and Severe Tracheobroncial Malacia.
Echocardiography
January 2025
Radiology Department, Hacettepe University Faculty of Medicine, Ankara, Turkey.
Left images: Top: (A) Echocardiography shows a dilated pulmonary artery, large aortopulmonary window (dotted line), and abnormally positioned aortic arch. (B) MIP image reveals superior RV, inferior LV, and elongated arch vessels (arrows). Bottom: MinIP shows a thin left main bronchus and non-aerated RML (asterisk).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!