Histological validation of simultaneous non-contrast angiography and intraplaque hemorrhage imaging (SNAP) for characterizing carotid intraplaque hemorrhage

The purpose of this study was to assess the vulnerability of plaque using a combination of simultaneous non-contrast angiography, intraplaque hemorrhage (SNAP) sequence, and local hemodynamic analysis in an intraplaque hemorrhage (IPH), and to evaluate the association between morphological and hemodynamic factors and IPH by comparing the IPH (presence of IPH) and non-IPH (plaque with absence of IPH) groups. In total, 27 IPH patients and 27 non-IPH patients were involved in this study, and baseline characteristics were collected. For morphological factors, diameters, and areas of the internal carotid artery (ICA), external carotid artery, and common carotid artery were measured, and bifurcation angle (α) and ICA angle (β) were also measured for comparison between the IPH group and non-IPH group. For hemodynamic factors, time-averaged wall shear stress (WSS), minimum WSS, maximum WSS, and oscillatory shear index were calculated using computational fluid dynamics (CFD) simulations. For the qualitative analysis, cross-sectional images with analyzed WSS and SNAP sequences were combined to precisely assess local hemodynamics. Bifurcation angle (α) was significantly different between the IPH and non-IPH groups (39.47 degrees vs. 47.60 degrees, p = 0.041). Significantly higher time-averaged WSS, minimum WSS, and maximum WSS were observed in the IPH group compared to the non-IPH group. In the IPH group, when using the combined analysis with SNAP sequences and WSS, the WSS of the region with IPH was significantly higher than the region without IPH (2.32 vs. 1.21 Pa, p = 0.005). A smaller bifurcation angle (α) and higher time-averaged WSS, minimum WSS, and maximum WSS were associated with IPH. The combined analysis of SNAP sequences and WSS might help to evaluate the risk of carotid IPH.

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Clinical and histological validation of rapid magnetic resonance myelin imaging in multiple sclerosis

10.26226/morressier.5b7578635aff7400151f38d2 ◽

2018 ◽

Author(s):

Russell Ouellette ◽

Tobias Granberg

Keyword(s):

Multiple Sclerosis ◽

Magnetic Resonance ◽

Myelin Imaging ◽

Histological Validation

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Faculty Opinions recommendation of Use of spiral computed tomography contrast angiography and ultrasonography to exclude the diagnosis of pulmonary embolism in the emergency department.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1099403.555654 ◽

2008 ◽

Author(s):

Paul Stein

Keyword(s):

Computed Tomography ◽

Emergency Department ◽

Pulmonary Embolism ◽

Spiral Computed Tomography ◽

Spiral Computed ◽

Contrast Angiography

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Colocalization of Erythrocytes and Vascular Calcification in Human Atherosclerosis: A Systematic Histomorphometric Analysis

TH Open ◽

10.1055/s-0041-1725042 ◽

2021 ◽

Vol 05 (02) ◽

pp. e113-e124

Author(s):

Elsa Wilma Böhm ◽

Maria Pavlaki ◽

Georgios Chalikias ◽

Dimitrios Mikroulis ◽

George S. Georgiadis ◽

...

Keyword(s):

Calcium Phosphate ◽

Aortic Valve ◽

Carotid Artery ◽

Vascular Tissue ◽

Osteoblastic Differentiation ◽

Aortic Aneurysms ◽

Vascular Lesions ◽

Erythrocyte Membranes ◽

Intraplaque Hemorrhage ◽

Alizarin Red

Abstract Background Intimal calcification typically develops in advanced atherosclerosis, and microcalcification may promote plaque progression and instability. Conversely, intraplaque hemorrhage and erythrocyte extravasation may stimulate osteoblastic differentiation and intralesional calcium phosphate deposition. The presence of erythrocytes and their main cellular components (membranes, hemoglobin, and iron) and colocalization with calcification has never been systematically studied. Methods and Results We examined three types of diseased vascular tissue specimens, namely, degenerative aortic valve stenosis (n = 46), atherosclerotic carotid artery plaques (n = 9), and abdominal aortic aneurysms (n = 14). Biomaterial was obtained from symptomatic patients undergoing elective aortic valve replacement, carotid artery endatherectomy, or aortic aneurysm repair, respectively. Serial sections were stained using Masson–Goldner trichrome, Alizarin red S, and Perl's iron stain to visualize erythrocytes, extracelluar matrix and osteoid, calcium phosphate deposition, or the presence of iron and hemosiderin, respectively. Immunohistochemistry was employed to detect erythrocyte membranes (CD235a), hemoglobin or the hemoglobin scavenger receptor (CD163), endothelial cells (CD31), myofibroblasts (SMA), mesenchymal cells (osteopontin), or osteoblasts (periostin). Our analyses revealed a varying degree of intraplaque hemorrhage and that the majority of extravasated erythrocytes were lysed. Osteoid and calcifications also were frequently present, and erythrocyte membranes were significantly more prevalent in areas with calcification. Areas with extravasated erythrocytes frequently contained CD163-positive cells, although calcification also occurred in areas without CD163 immunosignals. Conclusion Our findings underline the presence of extravasated erythrocytes and their membranes in different types of vascular lesions, and their association with areas of calcification suggests an active role of erythrocytes in vascular disease processes.

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