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Objective:To investigate the characteristics of early myocardial mechanics changes in diabetic cardiomyopathy (DCM).Method:Sixty healthy 4-week-old male C57BL/6J mice were randomly divided into the T2DM group ( n=30) and the control group ( n=30). The T2DM group was fed with high-fat diet for 4 weeks, and accepted injection of a single high-dose of streptozotocin (STZ) intraperitoneally. Finally, the model was established successfully in 23 mice. The control group was fed with a normal diet and treated with citrate buffer liquid at an equal dose as T2DM group. Then, nine mice were randomly selected from each of the two groups every 4 weeks until the end of the 24th week. Six of the nine mice were randomly selected to perform 7.0 T MR scanning after measuring blood glucose and body weight. Cine images were acquired through cardiovascular MR feature tracking (CMR-FT). The obtained parameters included the left ventricle global peak circumferential strain (LV-GPCS), left ventricle global peak radial strain(GPRS) and the ejection fraction (EF), etc. The rest three mice were sacrificed for observation of the changes of interstitial fibers and micro-vessels in myocardial tissue with Sirius red staining. One-way analysis of variance (ANOVA) and t test were used for comparison. Results:There were significant differences in blood glucose levels between the two groups during the observation period ( P<0.05). In the 4 th-24 th week, the value of GPCS in T2DM group showed a downward trend, and the difference was statistically significant ( F = 8.23, P<0.001). Compared with the control group, the value of GPCS in T2DM group was statistically significant at the 20 th and 24 th week (the 20 th week: -11.4%±2.1% in the T2DM group vs. -14.3%±1.9% in the control group, t=2.54, P=0.029;the 24 th week: -12.3%±1.7% in the T2DM group vs. -14.6%±1.8% in the control group, t=2.35 , P=0.040), while the EF value was different at the 24 th week (51%±5% in the T2DM group vs. 62%±6% in the control group, t=3.38, P=0.007). There was no significant difference in the GPRS of the T2DM mice group over time or compared with the controls ( P>0.05). Moreover, the pathological results showed that the myocardial interstitial fibers in the T2DM group had remarkably increased since the 12 th week. Conclusions:The alterations in myocardial interstitial fibers and myocardial contractility appeared early in T2DM mice. Especially, the left ventricle global peak circumferential strain value is superior to the EF value in reflecting the early changes in DCM.
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ObjectiveThe purpose of this paper is to grade hypervascularized mass lesions in CE MR imaging of the breast by analyzing morphology and dynamic characteristics.MethodsCriteria for the evaluation of breast MR findings were used,including the analysis of shape,margin,internal enhancement characteristics,initialenhancementphase,anddelayedphaseenhancementpattern.Atotalof 188 hypervascularized mass lesions were analyzed,and scores were given from 1 to 10 points and then the mass was classified into one of five categories.Next,the score results and pathology results were used to calculate the ROC curve and to find out the optimal benign and malignant diagnosis points.According to these results,the lesions were classified as benign or malignant.The sensitivity and specificity of this classification system were also calculated.ResultsOut of the 188 hypervascularized mass lesions,91 lesions were confirmed to be malignant by pathologic diagnosis and 97 to be benign.The area under the ROC curve was 0.938 ± 0.016.This curve was used to calculate the optimal point of differentiation diagnosis,and it was found to be a score of 5.The 188 lesions were classified into grade Ⅱ of 24 lesions,grade Ⅲ of 72,grade Ⅳ of 54,and grade Ⅴ of 38.Sensitivity for the detection of malignancy using this classification system was 87.91％ and specificity was 87.62％.If the three cases with false negative results of ductal carcinoma in situ of grade Ⅲ were excluded,the specificity increased to 90.90％.Conclusion The classification based on a multifactorial analysis is very helpful in the objective interpretation of breast CE MRI.