Value of four-dimensional automatic right ventricular quantitative analysis in evaluating right ventricular function in patients with dilated cardiomyopathy / 中华超声影像学杂志

Objective:To evaluate the right ventricular function in patients with dilated cardiomyopathy (DCM) by four-dimensional automatic right ventricular quantitative analysis (4D Auto RVQ), and compare with the right ventricular ejection fraction measured by cardiac magnetic resonance (CMR-RVEF), and to explore the clinical application value of 4D Auto RVQ technique in evaluating the right ventricular function of patients with DCM.Methods:A prospective study was conducted to select 52 patients with DCM who were treated in Fuwai Central China Cardiovascular Hospital of Zhengzhou University from March to October 2022 as DCM group, and 52 healthy volunteers were selected as the control group during the same period. The four-dimensional right ventricular ejection fraction (4D-RVEF), right ventricular stroke volume index (RVSVI), right ventricular end-diastolic volume index (RVEDVI), right ventricular end-systolic volume index (RVESVI), four-dimensional right ventricular basal diameter (4D-RVDd-base), four-dimensional right ventricular middle diameter (4D-RVDd-mid), four-dimensional right ventricular long axis diameter (4D-RVLd), four-dimensional tricuspid annular plane systolic excursion (4D-TAPSE) and four-dimensional right ventricular fractional area change (4D-RVFAC) were obtained by 4D Auto RVQ technique. The differences of the above parameters between DCM group and control group were compared.Pearson linear correlation analysis was used to evaluate the correlation between echocardiographic parameters and CMR-RVEF. The ROC curve was used to find the most sensitive parameters for evaluating right ventricular function, and the area under the ROC curve ( AUC ) was calculated and compared.Results:Compared with the control group, RVEDVI, RVESVI, 4D-RVDd-base and 4D-RVDd-mid in the DCM group were increased, and the absolute values of 4D-RVEF, 4D-TAPSE, 4D-RVFAC, right ventricular global longitudinal strain(RVGLS) and right ventricular free wall longitudinal strain(RVFWLS) were decreased (all P<0.05). Correlation analysis showed that 4D-RVEF was positively correlated with CMR-RVEF ( r=0.711, P<0.05). ROC curve analysis showed that 4D-RVEF was superior to other parameters in evaluating right ventricular function in DCM patients (AUC: 0.916). Conclusions:4D Auto RVQ technique can quantitatively evaluate right ventricular function in DCM patients. 4D-RVEF has a significant correlation with CMR-RVEF, and 4D-RVEF has the best efficacy in evaluating right ventricular function in DCM patients.

Analysis of neural fragility in epileptic zone based on stereoelectroencephalography / 生物医学工程学杂志

There are some limitations in the localization of epileptogenic zone commonly used by human eyes to identify abnormal discharges of intracranial electroencephalography in epilepsy. However, at present, the accuracy of the localization of epileptogenic zone by extracting intracranial electroencephalography features needs to be further improved. As a new method using dynamic network model, neural fragility has potential application value in the localization of epileptogenic zone. In this paper, the neural fragility analysis method was used to analyze the stereoelectroencephalography signals of 35 seizures in 20 patients, and then the epileptogenic zone electrodes were classified using the random forest model, and the classification results were compared with the time-frequency characteristics of six different frequency bands extracted by short-time Fourier transform. The results showed that the area under curve (AUC) of epileptic focus electrodes based on time-frequency analysis was 0.870 (delta) to 0.956 (high gamma), and its classification accuracy increased with the increase of frequency band, while the AUC by using neural fragility could reach 0.957. After fusing the neural fragility and the time-frequency characteristics of the γ and high γ band, the AUC could be further increased to 0.969, which was improved on the original basis. This paper verifies the effectiveness of neural fragility in identifying epileptogenic zone, and provides a theoretical reference for its further clinical application.

Effects of Magnetic Rewarming on Mechanical Properties of Vitrified Umbilical Artery / 医用生物力学

Objective To study the effect of magnetic rewarming on the morphology and biomechanical properties of vitrified umbilical artery. Methods The vitrified umbilical artery was rewarmed by magnetothermal method and traditional water bath. The temperature distribution and stress in the solution system were analyzed, and the rewarming effect was evaluated by tissue staining and mechanical test. Results Compared with water bath rewarming, the temperature gradient and thermal stress generated by magnetic rewarming were smaller, which could effectively reduce the thermal stress damage during the rewarming stage and achieve rapid and uniform rewarming. Magnetic rewarming could effectively avoid umbilical artery fractures and micro-cracks. After rewarming, the extracellular matrix, collagen fibers, elastic fibers and muscle fibers of the umbilical artery were evenly distributed, which preserved the macro and micro structures of the umbilical artery. The umbilical artery showed different degrees of hardening after water bath and magnetic rewarming, but the elastic modulus and limit stress of the latter were not significantly different from those of fresh umbilical artery, and the latter had unidirectional stretching characteristics similar to that of fresh umbilical artery, showing good elasticity and toughness. Conclusions Compared with water bath rewarming, magnetothermal method can effectively reduce the damage of rewarming stage, ensure the macroscopic, microscopic structure integrity of umbilical artery and better biomechanical properties. The research findings provide important references for cryopreservation of large tissues or organs such as umbilical artery.