👤 Jan Pennig

To compare a flow-independent, 3D isotropic non-contrast MRA (REACT), with time-resolved contrast-enhanced MRA (4D CE-MRA) for postoperative assessment of the pulmonary arteries in patients with congenital heart disease (CHD), with emphasis on different implant types. In this retrospective single-center study, 53 patients with CHD underwent clinically indicated cardiovascular magnetic resonance (CMR) including both 4D CE-MRA and REACT at 1.5T. Three radiologists independently scored image quality (IQ) as well as motion and susceptibility artifacts on 5-point Likert scales and measured the diameters of the pulmonary arteries (PAs) [main (MPA), left (LPA) and right pulmonary artery (RPA)]. Subgroup analysis was performed for stents, conduit/patch/valve (CPV), and no implant. Pooled across readers and PA segments, REACT achieved higher overall IQ than 4D CE-MRA (median 3.67 [3.00-4.17] vs. 3.00 [2.33-3.33]; p < 0.001) and provided significantly better motion scores (p < 0.001), whereas susceptibility scores were comparable between techniques. The proportion of fully diagnostic studies (3/3 segments) was similar (REACT 77.4%, 41/53; 4D CE-MRA 83.0%, 44/53; McNemar, p = 0.38). Diameter measurements showed excellent inter-reader agreement (ICC ≈ 0.89-0.95) and minimal bias between techniques; only the RPA yielded slightly smaller diameters in REACT (mean difference -0.85 ± 1.51mm, p < 0.001). In subgroup analysis, stented segments showed no IQ advantage of REACT (p > 0.99) with IQ being limited due to susceptibility artifacts in both 4D CE-MRA and REACT. In the CPV and the no implant group, REACT yielded a one point higher median IQ score (both p = 0.002) and one point less impaired by motion artifacts (CPV: p < 0.001; no implant: p = 0.002), while both techniques provided very high shares of diagnostic image quality (defined as IQ ≥ 2; both > 90%; p > 0.99). REACT enables robust, contrast-free postoperative imaging of the pulmonary arteries in patients with CHD with superior IQ and reduced motion artifacts compared to 4D CE-MRA, while maintaining highly reproducible diameter measurements. Stented segments remain a shared limitation. Show less

The repertoire of adhesion receptors and ligands is supported by molecules, which are primarily recognized for their roles in immunity. We have recently shown that the co-stimulatory molecule CD40 ligand (CD154/CD40L) is pro-atherogenic and serves as an adhesive ligand for cells expressing the integrin Mac-1 (CD11b/CD18). Here, we studied the role of endothelial CD40L in several models of cardiovascular inflammation. We generated mice with an endothelial cell-specific deficiency of CD40L, Bmx-Cre In this functional validation study, we demonstrate that endothelial cell-expressed CD40L serves as an adhesion molecule in different models of acute inflammation in the aortic, peritoneal, mesenteric, and coronary vasculature. CD40L may therefore represent a promising therapeutic target at the interface of adaptive immunity and myeloid inflammation. Show less