Low structure stress correlates positively with atherosclerotic plaque wall thickness: in vivo/ex vivo MRI-based 3D FSI models for human atherosclerotic plaques

2006 ◽  
Vol 39 ◽  
pp. S610
Author(s):  
C. Yang ◽  
D. Tang ◽  
V. Yarnykh ◽  
C. Yuan ◽  
T.S. Hatsukami ◽  
...  
Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 279
Author(s):  
Rik P. M. Moonen ◽  
Bram F. Coolen ◽  
Judith C. Sluimer ◽  
Mat J. A. P. Daemen ◽  
Gustav J. Strijkers

The purpose of our study was to monitor the iron oxide contrast agent uptake in mouse brachiocephalic artery (BCA) atherosclerotic plaques in vivo by quantitative T2-mapping magnetic resonance imaging (MRI). Female ApoE−/− mice (n = 32) on a 15-week Western-type diet developed advanced plaques in the BCA and were injected with ultra-small superparamagnetic iron oxides (USPIOs). Quantitative in vivo MRI at 9.4 T was performed with a Malcolm-Levitt (MLEV) prepared T2-mapping sequence to monitor the nanoparticle uptake in the atherosclerotic plaque. Ex vivo histology and particle electron paramagnetic resonance (pEPR) were used for validation. Longitudinal high-resolution in vivo T2-value maps were acquired with consistent quality. Average T2 values in the plaque decreased from a baseline value of 34.5 ± 0.6 ms to 24.0 ± 0.4 ms one day after injection and partially recovered to an average T2 of 27 ± 0.5 ms after two days. T2 values were inversely related to iron levels in the plaque as determined by ex vivo particle electron paramagnetic resonance (pEPR). We concluded that MRI T2 mapping facilitates a robust quantitative readout for USPIO uptake in atherosclerotic plaques in arteries near the mouse heart.


Author(s):  
Chun Yang ◽  
Joseph D. Petruccelli ◽  
Zhongzhao Teng ◽  
Chun Yuan ◽  
Gador Canton ◽  
...  

Atherosclerotic plaque rupture and progression have been the focus of intensive investigations in recent years. The mechanisms governing plaque progression and rupture process are not well understood. Using computational models based on patient-specific multi-year in vivo MRI data, our recent results indicated that 18 out of 21 patients studied showed significant negative correlation between plaque progression measured by vessel wall thickness increase (WTI) and plaque wall (structural) stress (PWS) [1]. In this paper, a computational procedure based on meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to simulate plaque progression. Participating patients were scanned three times (T1, T2, and T3, at intervals of approximately 18 months) to obtain plaque progression data. Vessel wall thickness (WT) changes were used as the measure for plaque progression. Starting from T2 plaque geometry, plaque progression was simulated by solving the solid model and adjusting wall thickness using plaque growth functions iteratively until time T3 is reached. Numerically simulated plaque progression showed very good agreement with actual plaque geometry at T3 given by MRI data. We believe this is the first time plaque progression simulation results based on multi-year patient-tracking data are reported. Multi-year tracking data and MRI-based progression simulation add time dimension to plaque vulnerability assessment and will improve prediction accuracy.


Author(s):  
Sayan Mondal ◽  
Chun Yang ◽  
Joseph D. Petruccelli ◽  
Chun Yuan ◽  
Fei Liu ◽  
...  

It has been well-accepted that atherosclerosis initiation and progression correlate positively with low and oscillating flow wall shear stresses. However, this shear stress mechanism cannot fully explain why advanced plaques continue to grow under elevated flow shear stress conditions. Our previous investigations using 3D computational models with fluid-structure interactions (FSI) based on in vivo/ex vivo magnetic resonance images (MRI) of human carotid atherosclerotic plaques indicated that there is a negative correlation between advanced plaque wall thickness and structural maximum principal stress (Stress-P1) in the plaque and a positive correlation between plaque wall thickness and flow shear stress [3].


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1838 ◽  
Author(s):  
Jessica Bridoux ◽  
Sara Neyt ◽  
Pieterjan Debie ◽  
Benedicte Descamps ◽  
Nick Devoogdt ◽  
...  

Since atherosclerotic plaques are small and sparse, their non-invasive detection via PET imaging requires both highly specific radiotracers as well as imaging systems with high sensitivity and resolution. This study aimed to assess the targeting and biodistribution of a novel fluorine-18 anti-VCAM-1 Nanobody (Nb), and to investigate whether sub-millimetre resolution PET imaging could improve detectability of plaques in mice. The anti-VCAM-1 Nb functionalised with the novel restrained complexing agent (RESCA) chelator was labelled with [18F]AlF with a high radiochemical yield (>75%) and radiochemical purity (>99%). Subsequently, [18F]AlF(RESCA)-cAbVCAM1-5 was injected in ApoE−/− mice, or co-injected with excess of unlabelled Nb (control group). Mice were imaged sequentially using a cross-over design on two different commercially available PET/CT systems and finally sacrificed for ex vivo analysis. Both the PET/CT images and ex vivo data showed specific uptake of [18F]AlF(RESCA)-cAbVCAM1-5 in atherosclerotic lesions. Non-specific bone uptake was also noticeable, most probably due to in vivo defluorination. Image analysis yielded higher target-to-heart and target-to-brain ratios with the β-CUBE (MOLECUBES) PET scanner, demonstrating that preclinical detection of atherosclerotic lesions could be improved using the latest PET technology.


Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3499 ◽  
Author(s):  
Devel ◽  
Almer ◽  
Cabella ◽  
Beau ◽  
Bernes ◽  
...  

Atherosclerosis is a major cardiovascular disease worldwide, that could benefit from innovative nanomedicine imaging tools and treatments. In this perspective, we here studied, by fluorescence imaging in ApoE-/- mice, the biodistribution of non-functionalized and RXP470.1-targeted nanostructured lipid carriers (NLC) loaded with DiD dye. RXP470.1 specifically binds to MMP12, a metalloprotease that is over-expressed by macrophages residing in atherosclerotic plaques. Physico-chemical characterizations showed that RXP-NLC (about 105 RXP470.1 moieties/particle) displayed similar features as non-functionalized NLC in terms of particle diameter (about 60-65 nm), surface charge (about −5 — −10 mV), and colloidal stability. In vitro inhibition assays demonstrated that RXP-NLC conserved a selectivity and affinity profile, which favored MMP-12. In vivo data indicated that NLC and RXP-NLC presented prolonged blood circulation and accumulation in atherosclerotic lesions in a few hours. Twenty-four hours after injection, particle uptake in atherosclerotic plaques of the brachiocephalic artery was similar for both nanoparticles, as assessed by ex vivo imaging. This suggests that the RXP470.1 coating did not significantly induce an active targeting of the nanoparticles within the plaques. Overall, NLCs appeared to be very promising nanovectors to efficiently and specifically deliver imaging agents or drugs in atherosclerotic lesions, opening avenues for new nanomedicine strategies for cardiovascular diseases.


2013 ◽  
Vol 59 (12) ◽  
pp. 1708-1721 ◽  
Author(s):  
Emma Raitoharju ◽  
Niku Oksala ◽  
Terho Lehtimäki

BACKGROUND MicroRNAs (miRNA, miR) are noncoding RNAs that regulate gene expression by hindering translation. miRNA expression profiles have been shown to differ in vivo and in vitro in many cellular processes associated with cardiovascular diseases (CVDs). The progression of CVDs has also been shown to alter the blood miRNA profile in humans. CONTENT We summarize the results of animal and cell experiments concerning the miRNA profile in the atherosclerotic process and the changes which occur in the blood miRNA profile of individuals with CVD. We also survey the relationship of these CVD-related miRNAs and their expression in the human advanced atherosclerotic plaque, thereby providing more insight into miRNA function in human atherosclerotic lesions. The miRNAs miR-126, -134, -145, -146a, -198, -210, -340*, and -92a were found to be expressed differently in the blood of individuals affected and unaffected by CVD. These differences paralleled those seen in tissue comparisons of miRNA expression in advanced atherosclerotic plaques and healthy arteries. Furthermore, several miRNAs associated with atherosclerosis in in vitro studies (such as miR-10a, -126, -145, -146a/b, -185, -210, and -326) were expressed in plaques in a similar pattern as was predicted by the in vitro experiments. The clinical implications of miRNAs in atherosclerosis as biomarkers and as possible drug targets are also reviewed. SUMMARY miRNA profiles in in vitro and in vivo studies as well as in human peripheral blood are quite representative of the miRNA expression in human atherosclerotic plaques. miRNAs appear promising in terms of future clinical applications.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaowei Zhao ◽  
Ohad Ziv ◽  
Reza Mohammadpour ◽  
Benjamin Crosby ◽  
Walter J. Hoyt ◽  
...  

AbstractRadiofrequency ablation (RFA) is commonly used to treat atrial fibrillation (AF). However, the outcome is often compromised due to the lack of direct real-time feedback to assess lesion transmurality. In this work, we evaluated the ability of polarization-sensitive optical coherence tomography (PSOCT) to measure cardiac wall thickness and assess RF lesion transmurality during left atrium (LA) RFA procedures. Quantitative transmural lesion criteria using PSOCT images were determined ex vivo using an integrated PSOCT-RFA catheter and fresh swine hearts. LA wall thickness of living swine was measured with PSOCT and validated with a micrometer after harvesting the heart. A total of 38 point lesions were created in the LA of 5 living swine with the integrated PSOCT-RFA catheter using standard clinical RFA procedures. For all lesions with analyzable PSOCT images, lesion transmurality was assessed with a sensitivity of 89% (17 of 19 tested positive) and a specificity of 100% (5 of 5 tested negative) using the quantitative transmural criteria. This is the first report of using PSOCT to assess LA RFA lesion transmurality in vivo. The results indicate that PSOCT may potentially provide direct real-time feedback for LA wall thickness and lesion transmurality.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1072 ◽  
Author(s):  
Sanna Hellberg ◽  
Johanna Silvola ◽  
Heidi Liljenbäck ◽  
Max Kiugel ◽  
Olli Eskola ◽  
...  

Atherosclerosis is characterized by the accumulation of oxidized lipids in the artery wall, which triggers an inflammatory response. Oxidized low-density lipoprotein (ox-LDL) presents amyloid-like structural properties, and different amyloid species have recently been recognized in atherosclerotic plaques. Therefore, we studied the uptake of the amyloid imaging agent [18F]Flutemetamol in atherosclerotic plaques. The binding of [18F]Flutemetamol to human carotid artery plaque was studied in vitro. In vivo uptake of the tracer was studied in hypercholesterolemic IGF-II/LDLR−/−ApoB100/100 mice and C57BL/6N controls. Tracer biodistribution was studied in vivo with PET/CT, and ex vivo by gamma counter and digital ex vivo autoradiography. The presence of amyloid, ox-LDL, and macrophages in the plaques was examined by immunohistochemistry. [18F]Flutemetamol showed specific accumulation in human carotid plaque, especially in areas positive for amyloid beta. The aortas of IGF-II/LDLR−/−ApoB100/100 mice showed large thioflavin-S-positive atherosclerotic plaques containing ox-LDL and macrophages. Autoradiography revealed 1.7-fold higher uptake in the plaques than in a lesion-free vessel wall, but no difference in aortic tissue uptake between mouse strains were observed in the in vivo PET/CT. In conclusion, [18F]Flutemetamol binds to amyloid-positive areas in human atherosclerotic plaques. Further studies are warranted to clarify the uptake mechanisms, and the potential of the tracer for in vivo imaging of atherosclerosis in patients.


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