Self‐gated, dynamic contrast‐enhanced magnetic resonance imaging with compressed‐sensing reconstruction for evaluating endothelial permeability in the aortic root of atherosclerotic mice. (23rd September 2022)

• Record Type: Journal Article
• Authors: Calcagno, Claudia; David, John A.; Motaal, Abdallah G.; Coolen, Bram F.; Beldman, Thijs; Corbin, Alexandra; Kak, Arnav; Ramachandran, Sarayu; Pruzan, Alison; Sridhar, Arthi; Soler, Raphael; Faries, Christopher M.; Fayad, Zahi A.; Mulder, Willem J. M.; Strijkers, Gustav J.
• Is Part Of: NMR in biomedicine. Volume 36:Number 1(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-23
• Subjects: atherosclerosis -- DCE‐MRI -- inflammation -- microvascularization -- mouse -- self‐gated; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.4823
• Languages: English
• ISSNs: 0952-3480

Abstract

Abstract : High‐risk atherosclerotic plaques are characterized by active inflammation and abundant leaky microvessels. We present a self‐gated, dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) acquisition with compressed sensing reconstruction and apply it to assess longitudinal changes in endothelial permeability in the aortic root of Apoe −/− atherosclerotic mice during natural disease progression. Twenty‐four, 8‐week‐old, female Apoe −/− mice were divided into four groups (n = 6 each) and imaged with self‐gated DCE‐MRI at 4, 8, 12, and 16 weeks after high‐fat diet initiation, and then euthanized for CD68 immunohistochemistry for macrophages. Eight additional mice were kept on a high‐fat diet and imaged longitudinally at the same time points. Aortic‐root pseudo‐concentration curves were analyzed using a validated piecewise linear model. Contrast agent wash‐in and washout slopes ( b 1 and b 2 ) were measured as surrogates of aortic root endothelial permeability and compared with macrophage density by immunohistochemistry. b 2, indicating contrast agent washout, was significantly higher in mice kept on an high‐fat diet for longer periods of time ( p = 0.03). Group comparison revealed significant differences between mice on a high‐fat diet for 4 versus 16 weeks ( p = 0.03). Macrophage density also significantly increased with diet duration ( p = 0.009). Spearman correlation between b 2 from DCE‐MRI and macrophage density indicated a weak relationship between the two parameters (r = 0.28, p = 0.20). Validated piecewise linear modeling of the DCE‐MRI data showed that the aortic root contrast agent washout rate is significantly different during disease progression. Further development of this technique from a single‐slice to a 3D acquisition may enable better investigation of the relationship between in vivo imaging of endothelial permeability and atherosclerotic plaques' genetic, molecular, and cellular makeup in this important model of disease. Abstract : Atherosclerotic plaques at high risk of causing cardiovascular events are characterized by a prominent inflammatory infiltrate accompanied by the presence of an extensive network of leaky microvessels. In this paper, we present a dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) acquisition and compressed sensing reconstruction to aortic root in mouse models of atherosclerosis. In a longitudinal study, we find that the contrast agent washout slope, calculated from this acquisition, is significantly different during the disease natural progression.