Objective To observe the protective effect of total flavonoids from hawthorn leaf on ligation-induced acute myocardial ischemia in anesthetized dogs. Methods The coronary arteries of anesthetized dogs were ligated to induce the model of acute myocardial ischemia. The indexes including the changes of ST segment in electrocardiogram (∑-ST and N-ST) and the release of LDH and CK were measured after treatment. Meanwhile,the size of myocardial ischemia was observed by TTC staining method. Result Total flavonoids from hawthorn leaf depressed the increase of ∑-ST and N-ST,decreased the release of LDH and CK,and reduced the myocardial ischemic size. Conclusion Total flavonoids from hawthorn leaf has an effect on relieving myocardial ischemia.

OBJECTIVETo propose a new method for automatic segmentation of manually determined knee articular cartilage into 9 subregions for T2 measurement.

METHODSThe middle line and normal line were automatically obtained based on the outline of articular cartilage manually drawn by experienced radiologists. The region of articular cartilage was then equidistantly divided into 3 layers along the direction of the normal line, and each layer was further equidistantly divided into 3 segments along the direction of the middle line. Finally the mean T2 value of each subregion was calculated. Bland-Altman analysis was used to evaluate the agreement between the proposed and manual subregion segmentation methods.

RESULTSThe 95% limits of agreement of manual and automatic methods ranged from -3.04 to 3.20 ms, demonstrating a narrow 95% limits of agreement (less than half of the minimum average). The coefficient of variation between the manual and proposed subregion methods was 4.04%.

CONCLUSIONThe proposed subregion segmentation method shows a good agreement with the manual segmentation method and minimizes potential subjectivity of the manual method.

Adult ; Cartilage, Articular ; anatomy & histology ; Humans ; Knee Joint ; anatomy & histology ; Magnetic Resonance Imaging ; methods ; Young Adult

ObjectiveTo explore the diagnostic value of dual-energy computed tomography （DECT） for left atrial appendage thrombosis/spontaneous echocardiographic contrast （LAAT/SEC）. MethodsA retrospective analysis was done on 64 non-valvular atrial fibrillation patients who planned to undergo radiofrequency ablation between November 2020 and November 2021. All patients underwent DECT and transesophageal echocardiography （TEE）， and then were divided into LAAT/SEC group and non-LAAT/SEC group based on the TEE results. The clinical data and imaging parameters of the two groups were compared and analyzed. Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors for LAAT/SEC， and a prediction model was constructed. ResultsA total of 64 patients with atrial fibrillation were enrolled in this study， including 42 non-LAAT/SEC patients and 22 LAAT/SEC patients. There was no statistically significant difference in gender and body mass index （BMI） between the two groups （P > 0.05）. CHA₂DS₂-VASc score and left atrial diameter were higher in the LAAT/SEC group than in the non-LAAT/SEC group （P = 0.047； P < 0.001）. Significant differences （P < 0.001） were observed in the ratio of Hounsfield unit of LAA and ascending aorta （LAA/AA HU ratio） at the first phase of DECT and quantitative parameters such as Zeff， Rho， λHu， and nIC. Multivariate logistic regression showed that Zeff and Rho were the independent factors for the diagnosis of LAAT/SEC. A Zeff-Rho based model predicting LAAT/SEC was subsequently developed， with Area Under the Curve （AUC） of 0.96 （95% CI： 0.92， 1.00） and the accuracy of 0.92 （95% CI： 0.83， 0.97）. ConclusionsThe two quantitative parameters Zeff and Rho are independent risk factors for the diagnosis of LAAT/SEC. The DECT derived Zeff and Rho may have better diagnostic performance than single parameter and conventional CT in detecting LAAT/SEC.