The influence of flow distribution strategy for the quantification of pressure- and wall shear stress-derived parameters in the coronary artery: A CTA-based computational fluid dynamics analysis.

For image-based computational fluid dynamics (CFD) analysis to characterize the local coronary hemodynamic environment, the accuracy depends on the flow rate which is in turn associated with outlet branches' morphology. A good flow distribution strategy is important to mitigate the effect when certain branches cannot be considered. In this study, stenotic coronary arteries from 13 patients were used to analyze the effect of missing branches and different flow distribution strategies. Pressure- and wall shear stress (WSS)-derived parameters around the stenotic region (ROI) were compared, including fractional flow reserve (CT-FFR), instantaneous wave-free ratio (CT-iFR), resting distal to aortic coronary pressure (CT-Pd/Pa), time-averaged WSS, oscillatory shear index (OSI) and relative residence time (RRT). Three flow distribution strategies were the Huo-Kassab model at distal outlets (Type I), flow distribution based on outlet resistances (Type II), and a developed algorithm distributing flow at each bifurcation until the final outlets (Type III). Results showed that Type III strategy for models with truncated branch(es) had a good agreement in both pressure- and WSS-related results (interquatile range less than 0.12% and 4.02%, respectively) with the baseline model around the ROI. The relative difference of pressure- and WSS-related results were correlated with the flow differences in the ROI to the baseline mode. Type III strategy had the best performance in maintaining the flow in intermediate branches. It is recommended for CFD analysis. Removal of branches distal to a stenosis can be undertaken with an improved performance and maintained accuracy, while those proximal to the ROI should be kept.

Multimodal imaging study of hepatic perivascular epithelioid cell tumors: a case report.

Hepatic perivascular epithelioid cell tumors (PEComas) are rare interstitial tumors that are often misdiagnosed as hepatocellular carcinomas due to their unique vascular enhancement patterns. Herein, we present a case of a 61-year-old man who was incidentally found to have a lesion in the left medial segment of the liver during a chest computed tomography (CT) examination performed 4 days prior to his presentation for chest discomfort. Imaging revealed solid components with density similar to that of normal liver tissue and areas of low-density adipose tissue within the lesion. The solid components exhibited increased uptake of fluorine-18 fluorodeoxyglucose on positron emission tomography/CT. Magnetic resonance imaging demonstrated areas with unevenly high signal intensity in both T1-weighted imaging (T1WI) in-phase and T2-weighted imaging (T2WI) sequences, while T2WI in the opposite phase displayed areas with unevenly low signal intensity, indicating the presence of fatty components. Contrast-enhanced T1WI displayed a "fast in and fast out" enhancement pattern. These distinct imaging features contribute to the diagnosis of hepatic PEComas and distinguish it from hepatocellular carcinoma.

[Effects of Salvia miltiorrhiza on oxidative stress and microinflammatory state in patients undergoing continuous hemodialysis].

OBJECTIVE: To investigate the effects of Salvia miltiorrhiza (SM) on oxidative stress and microinflammatory state in patients undergoing continuous hemodialysis (CHD). METHODS: Thirty-six patients who had received CHD for over half a year were assigned into the routine CHD group (18 cases) and the treated group treated with routine CHD plus SM (18 cases). Meanwhile, 18 healthy adults were taken as the normal control. Indexes related with oxidative stress [malondialdehyde (MDA), advanced oxidative protein products (AOPP) and superoxide dismutase (SOD)) and microinflammation C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were detected before and after 1, 2 and 3 months of treatment. RESULTS: The levels of AOPP, MDA, CRP, IL-6 and TNF-alpha in patients were higher and SOD was lower than those in the normal control at all the time points (P < 0.01). Compared with the baseline, the levels of AOPP and MDA in the routine CHD group significantly increased and SOD decreased after 3 months of treatment (P < 0.05), but changes of CRP, IL-6 and TNF-alpha showed no significance though there were somewhat increment (P > 0.05). The levels of AOPP and MDA were lower and SOD was higher after 1, 2 and 3 months of SM combined treatment, and CRP was lower after 3 months of treatment in the treated group than those of baselines and those at the corresponding time points in the routine CHD group (P < 0.01), but IL-6 and TNF-alpha reduced insignificantly (P > 0.05). CONCLUSION: Hemodialysis may aggravate the oxidative stress and microinflammation in patients, which could be obviously alleviated by SM.