Objective To explore the application values of magnetic resonance diffusion weighted imaging (DWI)and diffusion tensor imaging (DTI)in the early diagnosis of cerebral infarction.Methods 1 2 1 patients with single side cerebral infarction were di-vided into five groups by disease time,the brain examination was performed by conventional MRI,DWI and DTI in every case.The le-sions were observed and compared in different sequences imaging.Mean diffusivity(MD)and fractional anisotropy(FA)values of cere-bral infarction lesions and the symmetrical positions in normal hemispheres were measured and compared.The correlations between relative MD(rMD)value,relative FA(rFA)value and disease time were analyzed.Results The display rate on DWI in showing ultra-acute and acute cerebral infarction lesions was 100%,which was superior to that on other sequences of conventional MRI obviously (P<0.05).Compared with the healthy sides,MD values of infarction lesions were lower at ultra-acute and acute phase(P<0.001), but at sub-acute phase,there was no statistically difference between the affected and normal sides(P>0.05).MD value was higher at early chronic and late chronic phase(P<0.001);FA values had no consistent changes at ultra-acute phase(P>0.05),but at the later separate phases,FA values reduced successively(P<0.001).The rMD value of infarction lesions was positive correlated with disease time(rs=0.990,P<0.001).The rFA value of infarction lesions was negative correlated with disease time(rs=-0.994,P<0.001). Conclusion DWI is susceptive in showing cerebral infarction lesions at hyper-early phase.DTI can be used to determine the clinical phase and appraise the inj ured extent of cerebral infarction accurately by measuring the parameters.Combination of DWI and DTI can provide a basis for clinical individual treatment programs selection and prognostic evaluation.

Objective Analyze the causes of the conversion from off-pump coronary artery bypass (OPCAB) to on-pump coronary artery bypass grafting (ONCAB), in order to improve the operative survival rate. Methods From January 2000 to December 2003, 1952 patients underwent OPCAB. 29 patients (1.49%) required conversion from OPCAB to ONCAB. The causes of conversion included ventricular fibrillation in 5 cases, and hypotension in 24 cases. 26 patients received CABG under CPB. 8 patients under aortic cross clamping, and 3 patients needed only CPB support. Results The mean number of grafts was 2.9?0.6. 9 patients died, postoperatively with a mortality rate of 31.03%. In patients with the perioperative blood pressure lower than 80/40?mm?Hg, the mortality rate was 47.6%, and in patients with blood pressure higher than 80/40?mm?Hg, the mortality rate was 8.33% (P=0.043). No one with duration of hypotension less than 15min died, the mortality of the patients with hypotension times more than 15min was 42.86% (P=0.029). In the death group, all the patients had more than three vessel disease and severe vessel stenosis or occlusion. The mortality was hither in female patients. Conclusion Patients converting from OPCAB to ONCAB had a higher mortality. The severity and lasting time of hypotension is closely correlated with the mortality rate. The high risk factors included the surgeons with less OPCAB experience, the patients with more than three vessel diseases and severe coronary stenosis or occlusion, and female patients. The indication of OPCAB must be strictly controlled. Hypotension and severe ventricular fibrillation occurred during OPCAB must be corrected and eliminated immediately.

PurposeTo observe the effects of blocking the renin-Angiotensin-Aldosterone system at different sites in experimental congestive heart failure (CHF)rats. Methods Six weeks after coronary ligation, rats( n = 66)were randomized to benalapril, losartan, spironolactone, placebo, and treated for 6 weeks. Sham-operated rats( n = 18) served as controls. Six weeks later left ventricular hemodynamics were measured. Results In the hemodynamic variables, HR was not significantly different between groups. Compared four treatment groups with sham-operated group, LVEDP increased, LVPSP and ± dp/dtmax decreased (P＜0.05). Compared with placebo group,all data in spironolactone group were not significantly different, LVEDP, mortality in benalapril group and in losartan group decreased, LVPSP and ± dp/dtmax in benalapril group and in losartan group increased(P ＜ 0.05). ConclusionsAdministration of ACEI and Ag Ⅱ-AT1 antagonist are effective in preventing from cardiac function deterioration, while spironolactone treatments are not. Spironolactone has tendency in decreasing LVEDP.

Objective To investigate the clinical and CT manifestations of iatrogenic hepatic subcapsular biloma (HSB).Methods Seven cases with iatrogenic HSB confirmed by paracentesis in our hospital,and 18 reported in literatures were enrolled into this study.Their clinical and CT manifestations were retrospectively analyzed.Results Of the 25 cases,9 were secondary to laparoscopic cholecystectomy (LC),5 were secondary to percutaneous transhepatic choleductus drainage (PTCD),4 were secondary to percutaneous transhe-patic removal of bile duct stones,2 were secondary to open cholecystectomy,and 5 were secondary to other surgeries.CT showed localized or diffused hepatic subcapsular fluid collection with crescent-shaped or sac-shaped.The hepatic volume decreased and the surface was compressed in some of the cases with diffused fluid collection.Conclusion When localized or diffused hepatic subcapsular fluid collection was detected in CT imaging after liver or gallbladder surgeries (especially LC and PTCD),HSB should be considered.Paracentesis should be performed as soon as possible.

Objective To explore CT diagnosis of atypical meningioma .Methods 18 cases of atypical meningioma were undergone MR plan scans, among them,17 cases were examined by CT contrast scans. All cases were proved by operation and pathology.Results The tumors appeared as mixed density in 11 cases,cystic in 4 cases,complete enhancement in 3 cases.Conclusion The tumors to be comfirmed at external cerebra is the key in diagnosing atypical meningioma exactly by CT.Atypical manifestations can be seen in a few meningiomas,therefore, it is significant in differential diagnosis of meningioma.

Objective To compare the effects of forming atherosclerosis by conducting ballon injury operation after 1th, 2th and 3th week of Vitamin D3(VD3) i.p., exploring the best method for atherosclerosis modeling .Methods 36 male rats were selected for balloon-injured carotid artery .SD rats were divided into 4 groups randomly:control group ( n=6), Model group1 (n=10), Model group2(n=10), Model group3 (n=10).Control group were fed up with common diet.Model groups were fed up with high-fat diet and injected 4.0 ×105 IU/kg VD3 through enterocoelia in the beginning , followed by the balloon-injured left carotid artery operation after 1th, 2th and 3th week respectively and 1.0 ×105 IU/kg VD3injection at 0th, 2th week after operation.The rats were killed at 4th week after operation.The serum levels of TG, TC, HDL-C and LDL-C were checked .ELISA was used to detect the content of hsCRP , IL-6 and TNFα.HE staining was used to observe the pathological changes in the thoracic aorta , and the thoracic aorta thickness , plaque area ( PA) , cross-sectional area of vessel ( CVA) and the ratio of PA to CVA ( PA/CVA) were analyzed .Results After 4 weeks of operation , levels of TC and LDL-C were significantly increased in Model group 2 and 3 compared with that of the control group ( P<0.05).Furthermore, contents of hsCRP, IL-6 and TNFαof model groups were also seriously higher than that of the control group (P<0.05), and that of Model group 3 were the highest.Typical AS plagues were observed in different degrees in model groups, and thoracic aorta thickness and PA/CVA were obviously increased than that of control group (P<0.05). Model group 3 turned out masses of lipid foam cells accumulated , and PA, CVA and PA/CVA were significantly increased than that of Model group2 or 3.Conclusion The AS model can be established successfully in rats with ballon injury after 3 weeks of high-fat diet plus VD3 i.p., which is the ideal method to induced atherosclerosis model .

Objective:To investigate the diagnostic value of synthetic MRI methods in the differentiation of benign and malignant breast lesions.Methods:Clinical and imaging data of 93 breast patients confirmed by pathology in the Second Affifiliated Hospital of Xi′an Jiaotong University from May 2019 to April 2020 were analyzed retrospectively. All patients underwent synthetic MRI technique, and the quantitative parameters of T 1, T 2, and proton density (PD) values were measured. Independent samples t-test and Wilcoxon test were used to compare the differences in clinical and imaging characteristics between the benign and malignant breast lesions. ROC curve was used for the comparison of the diagnostic efficacy of the quantitative parameters in differentiating malignant from benign breast lesions. Results:Of the 93 patients with breast lesions, 62 cases were malignant and 31 cases were benign. The quantitative T 2 values for benign and malignant lesions were 103 (93, 126)ms and 83 (77, 90)ms respectively, and the quantitative PD values were 87.7 (72.7, 96.7)pu and 73.5(63.3, 79.4)pu respectively. There were statistically significant differences between benign and malignant lesion( P<0.05). Taking quantitative T 2 values of 90.5 ms and PD values of 84.8 pu as the cut-off value, the area under the ROC curve in differentiating benign from malignant breast lesions were 0.87 and 0.75, accuracy values were 80.6% and 78.5%, specificity values were 87.1% and 54.8%, sensitivity values were 77.4% and 90.3% respectively. Conclusion:Synthetic MRI methods can be applied in the examination of breast lesions and has the potential to be an effective diagnostic method for the differential diagnosis between benign and malignant lesions of breast.

Objective To investigate the value of diffusion tensor imaging(DTI)in the evaluation of diffuse microstructural changes in early stage of spinal cord injury (SCI)in rats.Methods Improved Allen's method was used to make SCI in rats model.The rats were divided in the group of four as control,mild,moderate and severe injury groups respectively.We used DTI parameters [fraction anisotropy (FA)and apparent diffusion coefficient(ADC)]values to observe the spinal cord at different stages (6,24 and 72 hours) after spinal injury in the rats.Results The FA value of the spinal cord began to decrease at 6 hours and reached the lowest at 24 hours after SCI (P<0.05).There were significant differences in FA values between mild,moderate,and severe injury groups (P<0.05). However,ADC value was seen decreased only in the severe injury group,which was lowest at 24 hours after SCI(P<0.05).Conclusion Compared with ADC value,FA value can better reflect the severity of spinal cord injury in rats with acute SCI.FA values are correlated with the degrees of injury of spinal cord.

Objective To study the distribution characteristics of myocardial fat infiltration and to analyze the function of the left ventricle (LV).Methods The images of patients who performed coronary CT angiography (CTA)in Siemens DSCT were reviewed retrospectively.The imaging characteristics and location of myocardial fat infiltration were recorded and the LV function was analyzed by Siemens Syngo.via software.Results Totally 4 477 patients were enrolled in this study.Among them,myocardial fat infiltration of the LV was found in 94 (accounting for 2.1%)patients.The fat infiltration was mainly located underlying the endocardium,including the inferior,anterior,lateral and posterior walls of the LV,as well as the inferior part of the interventricular septum.The enhancement image showed low intensity in the myocardium with fat infiltration.Conclusion The characteristics of myocardial fat infiltration can be well displayed by DSCT,as well as the LV function.DSCT can provide both morphological and functional information of the heart via one scan.

Objective To explore the clinical value of magnetic resonance time-resolved imaging of contrast kinetics (MR-TRICKS)in the assessment of lower extremity venous lesions in Klippel-Trenaunay syndrome (KTS).Methods Image data of 20 patients (total 21 affected limbs)diagnosed with KTS in our hospital were analyzed retrospectively.All patients underwent MR-TRICKS angiography and ascending phlebography of the lower extremities.The images acquired by these two methods were graded and compared.Kappa test was used to examine the consistency between the results of two inspection methods.Results The image quality of MR-TRICKS angiography and ascending phlebography graded on excellent proportion were 85.71％(18/21)and 80.95％(17/21)for the deep veins,95.24％(20/21)and 90.48％(19/21)for the superficial veins,and 90.48％(19/21)and 85.71％(18/21) for venous malformation,respectively.MR-TRICKS demonstrated that the deep veins were normal in 61.90％ (13/21),hypogenetic in 25.57％(7/21),atretic in 4.86％(1/21).Superficial vein diseases including varicosis of the great saphenous vein accounted for 25.57％(6/21), varicosis of the small saphenous vein accounted for 14.29％ (3/21 ),while marginal veins in venous malformation accounted for 100％ (21/21).Ascending phlebography of the lower limbs showed that the deep veins were normal in 57.14％(12/21)and dysplasia in 39.10％(8/21),while the other results were consistent with those of TRICKS.Consistency between results from the two methods were excellent (Kappa >0.75).Conclusion MR-TRICKS can accurately describe the angioarchitecture of the lower extremity vena in patients with KTS,and has an important clinical value in providing support for the assessment and treatment of KTS.