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The occurrence of earthquakes has been recognized as a natural disaster capable of significantly impacting land use/cover change (LUCC) patterns. During the post-earthquake recovery and reconstruction phase, obtaining an accurate and scientific grounded understanding of the LUCC process in the affected area is essential for analyzing the subsequent changes in recovery and identifying the underlying driving forces. In this study, we selected the 2014 Ludian Ms6.5 earthquake as the focal point of our research. Through the utilization of Google Earth Engine and Landsat 8 OLI remote sensing image, we employed the Random Forest classification algorithm to analyze the structural and transformational changes of LUCC in Ludian County prior to and post the earthquake. In addition, we produced comprehensive post-earthquake damage map and recovery map through the LUCC transfer amount to analyze each township's damage and recovery degree quantitatively. Finally, we employed the geographic detector to investigate the driving factors contributing to the post-earthquake recovery degree. As is demonstrated by our results, the earthquake inflicted substantial damage on cropland, grassland, and built-up areas, with Longtoushan Town and Huodehong Town suffering the most severe damage. After three years, we found that cropland and built-up areas had been restored, while previously unused land had been successfully treated, yielding initial restoration progress. Upon reaching the six-year mark, built-up areas continued to expand, while cropland acreage exhibited a decline in comparison to the P1 and P2 phases. Concurrently, forest and grassland areas increased relative to the P1 and P2 phases, signifying Ludian County's successful restoration. The factor detection results show that socio-economic factors are potent factors that promote post-earthquake recovery, and the earthquake factors also have a continuous impact. The research results can serve as a valuable reference for informing local disaster area reconstruction planning as well as ensuring effective protection of ecological environment. [ABSTRACT FROM AUTHOR]

Objective: To analyze the relationship between the collateral flow of coronary chronic total occlusion (CTO) and myocardial viability detected by 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging.Methods: A prospective analysis of 104 patients diagnosed by coronary angiography. All patients underwent resting myocardial perfusion imaging and PET/CT within 1 week. The collateral circulation was graded with Rentrop classification as no or poor collateral circulation in 16 CTO vessels, moderate collateral circulation in 34 CTO vessels, and good collateral circulation in 69 CTO vessels. Myocardial viability was determined with myocardial perfusion imaging and PET. The patterns were interpreted as mismatch, match and normal perfusion and 18F-FDG uptake.Results: There was no significant correlation between the severity and extent of perfusion defect, myocardial viability and collateral circulation grade. The myocardial viability was normal in mild and moderate hypokinetic regions and decreased in severe hypokinetic and akinesis-dyskinesis regions. The presence of collateral circulation was a sensitive (89%) but not a specific (31%) sign of myocardial viability.Conclusions: In patients with CTO, collateral circulation does not seem to be an effective way for predicting myocardial viability. Further analysis of PET patterns of viable myocardium is needed to guide further revascularization and predict functional improvement and survival benefit. [ABSTRACT FROM AUTHOR]

A translocator protein 18 kDa targeted radiotracer, N,N-diethyl-2-(2-(4-[18F]fluorophenyl)-5,7-dimethylpyrazolo[1,5-a] pyrimidin-3-yl) acetamide ([18F]FDPA), was automated synthetized and evaluated for cardiac inflammation imaging. Various reaction conditions for an automated synthesis were systematically optimized. MicroPET/CT imaging were performed on normal rats and rats with myocardial infarction (MI). Normalized SUV ratios of [18F]FDPA to [13N]NH3 (NSRs) in different regions were calculated to normalize the uptake of [18F]FDPA to perfusion. The amount of TBAOMs and the volume/proportion of water were crucial for synthesis. After optimization, the total synthesis time was 68 min. The non-decay corrected radiochemical yields (RCYs) and molar activities were 19.9 ± 1.7% and 169.7 ± 46.5 GBq/μmol, respectively. In normal rats, [18F]FDPA showed a high and stable cardiac uptake and fast clearance from other organs. In MI rats, NSRs in the peri-infarct and infarct regions, which were infiltrated with massive inflammatory cells revealed by pathology, were higher than that in the remote region (1.20 ± 0.01 and 1.08 ± 0.10 vs. 0.89 ± 0.05, respectively). [18F]FDPA was automated synthesized with high RCYs and molar activities. It showed a high uptake in inflammation regions and offered a wide time window for cardiac imaging, indicating it could be a potential cardiac inflammation imaging agent. [ABSTRACT FROM AUTHOR]

Background: Magnetocardiography (MCG) is a novel non-invasive technique that detects subtle magnetic fields generated by cardiomyocyte electrical activity, offering sensitive detection of myocardial ischemia. This study aimed to assess the ability of MCG to predict impaired myocardial perfusion using single-photon emission computed tomography (SPECT)., Methods: A total of 112 patients with chest pain underwent SPECT and MCG scans, from which 65 MCG output parameters were analyzed. Using least absolute shrinkage and selection operator (LASSO) regression to screen for significant MCG variables, three machine learning models were established to detect impaired myocardial perfusion: random forest (RF), decision tree (DT), and support vector machine (SVM). The diagnostic performance was evaluated based on the sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC)., Results: Five variables, the ratio of magnetic field amplitude at R-peak and positive T-peak (RoART+), R and T-peak magnetic field angle (RTA), maximum magnetic field angle (MAmax), maximum change in current angle (CCAmax), and change positive pole point area between the T-wave beginning and peak (CPPPATbp), were selected from 65 automatic output parameters. RTA emerged as the most critical variable in the RF, DT, and SVM models. All three models exhibited excellent diagnostic performance, with AUCs of 0.796, 0.780, and 0.804, respectively. While all models showed high sensitivity (RF = 0.870, DT = 0.826, SVM = 0.913), their specificity was comparatively lower (RF = 0.500, DT = 0.300, SVM = 0.100)., Conclusions: Machine learning models utilizing five key MCG variables successfully predicted impaired myocardial perfusion, as confirmed by SPECT. These findings underscore the potential of MCG as a promising future screening tool for detecting impaired myocardial perfusion., Clinical Trial Registration: ChiCTR2200066942, https://www.chictr.org.cn/showproj.html?proj=187904., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2024 The Author(s). Published by IMR Press.)

Inflammation induced by activated macrophages within vulnerable atherosclerotic plaques (VAPs) constitutes a significant risk factor for plaque rupture. Translocator protein (TSPO) is highly expressed in activated macrophages. This study investigated the effectiveness of TSPO radiotracers, 18 F-FDPA, in detecting VAPs and quantifying plaque inflammation in rabbits. 18 New Zealand rabbits were divided into 3 groups: sham group A, VAP model group B, and evolocumab treatment group C. 18 F-FDPA PET/CTA imaging was performed at 12, 16, and 24 weeks in all groups. Optical coherence tomography (OCT) was performed on the abdominal aorta at 24 weeks. The VAP was defined through OCT images, and ex vivo aorta PET imaging was also performed at 24 weeks. The SUV max and SUV mean of 18 F-FDPA were measured on the target organ, and the target-to-background ratio (TBR max ) was calculated as SUV max /SUV blood pool . The arterial sections of the isolated abdominal aorta were analyzed by HE staining, CD68 and TSPO immunofluorescence staining, and TSPO Western blot. The results showed that at 24 weeks, the plaque TBR max of 18 F-FDPA in group B was significantly higher than in groups A and C. Immunofluorescence staining of CD68 and TSPO, as well as Western blot, confirmed the increased expression of macrophages and TSPO in the corresponding regions of group B. HE staining revealed an increased presence of the lipid core, multiple foam cells, and inflammatory cell infiltration in the area with high 18 F-FDPA uptake. This indicates a correlation between 18 F-FDPA uptake, inflammation severity, and VAPs. The TSPO-targeted tracer 18 F-FDPA shows specific uptake in macrophage-rich regions of atherosclerotic plaques, making it a valuable tool for assessing inflammation in VAPs.