Objective To measure changes in the basal ganglia volume,characteristics of neu-romelanin in substantia nigra-1 and iron deposition using susceptibility-weighted imaging(SWI)in Parkinson's disease(PD)patients with freezing of gait at different stages,and to explore their value in evaluating these stages.Methods A total of 178 PD patients with freezing of gait were enrolled.According to Hoehn-Yahr stage,the patients were divided into stage Ⅰ to Ⅱ group(112 cases)and divided into stage Ⅲ to Ⅴ group(66 cases).Additionally,70 healthy volunteers undergoing routine physical examinations were randomly selected as control group.SWI was used to measure basal gan-glia volumes(globus pallidus,putamen and caudate nucleus),disappearance rate of substantia nigra-1(including bilateral display,unilateral display and bilateral non-display),and iron deposition(phase shift values)among groups.Multivariate logistic regression analysis was conducted to identify imaging factors associated with different stages.Receiver operating characteristic(ROC)curve analy-sis was performed to calculate the area under the curve(AUC)for assessing the predictive perform-ance of imaging factors.Results The course of disease in stage Ⅲ to Ⅴ group was significantly lon-ger,and the Parkinson's Comprehensive Assessment Scale(UPDRS)score was significantly higher than that in stage Ⅰ to Ⅱ group(P＜0.05).The volume of pallidum,putamen and caudate nucleus in stage Ⅰ to Ⅱ and stage Ⅲ to Ⅴ groups were significantly lower,and those in stage Ⅲ to Ⅴgroup were significantly lower than that in stage Ⅰ to Ⅱ group(P＜0.05);the disappearance rate of substantia nigra-1 and the deposition amount of pallidum iron,putaminal iron as well as caudate i-ron in stage Ⅰ to Ⅱ and stage Ⅲ to Ⅴ groups were significantly higher,and those in stage Ⅲ to Ⅴgroup were significantly higher than that in stage Ⅰ to Ⅱ group(P＜0.05).Logistic regression analysis indicated that decreased caudate nucleus volume(OR=1.856,95％CI,1.234 to 2.564,P＜0.001),disappearance of substantia nigra-1(OR=2.235,95％CI,1.657 to 2.659,P＜0.001)and increased iron deposition in the globus pallidus(OR=1.562,95％CI,1.234 to 1.989,P＜0.001)were predictors of Hoehn-Yahr staging.ROC showed that the AUC of Hoehn-Yahr stage was 0.889 based on the combination of caudate volume,disappearance of substantia nigra-1 and depo-sition of pallidum.Conclusion SWI is an important non-invasive imaging tool for assessing different stages in PD patients with freezing of gait.Caudate nucleus volume,substantia nigra-1 and iron depo-sition in the globus pallidus are key indicators for predicting Hoehn-Yahr staging.

Objective To investigate the value of standardized iodine concentration and energy spectrum curve of dual-source CT in diagnosis of metastatic lymph nodes of gastric cancer.Methods The clinical data of 60 patients diagnosed as gastric cancer were collected in our hospital.All patients underwent dual-source CT routine abdominal scanning and dual-phase energy spectrum enhancement.According to the pathologic results,the lymph nodes were divided into metastatic and non-metastatic groups.Then the enhanced degree,dual-phase normalized iodine concentration (NIC)were measured and compared between metastatic lymph nodes and non-metastatic lymph nodes.The slope of the energy spectrum curve of metastatic lymph nodes and non-metastatic lymph nodes were calculated by dual-energy software.Results When the enhanced degree was higher than 80 HU,the sensitivity (82.4%)and specificity (78.6%)were higher. The artery-phase NIC values of metastatic lymph node and non-metastatic lymph node were(0.546±0.086)and(0.144±0.077),respectively. The difference was statistically significant (P<0.05).The venous-phase NIC values of metastatic lymph node and non-metastatic lymph nodes were (0.479±0.013)and (0.307±0.082),respectively.The difference was statistically significant (P<0.05).The dual-phase energy spectrum curves of metastatic and non-metastatic lymph nodes were all descending patterns.The difference was obvious at 40-80 keV and minimal at 80-140 keV.The sensitivity of diagnosing metastatic lymph nodes was 83.5%,and the specificity was 85.6%when the arterial curve slope was 6.87.The sensitivity of diagnosing metastatic lymph nodes was 63.6% and the specificity was 96.7%when the venous curve slope was 6.67.Conclusion The multiple parameters provided by dual-source CT dual-energy imaging are helpful to the qualitative and quantitative diagnosis of metastatic lymph nodes in gastric cancer.

Objective To explore the accuracy and feasibility of dual-source CT(DSCT)in evaluating the left ventricular function compared with echocardiography.Methods 30 cases of coronary heart disease were continuously collected in our hospital ,and dual-source CT and echocardiography were examined in a week.Left ventricular function parameters (LVEDV,LVESV,LVSV)were measured,and paired sample t test was compared to show whether there was any difference between the two methods,Rates betweengroups were compared with Chi-square test,Pearson correlation analysis method was applied to calculate the correlation between the two methods.Results There was no statistically significant difference for LVEDV,LVESV,LVSV,LVEF parameters between the two methods (t test,P >0.05).By Pearson test,the correlation coefficient was r=0.770-0.938(P <0.05),in which the high relation between the two methods was showed.Conclusion A strong accuracy of dual-source CT in evaluating left ventricular function is demonstrated.Dual-source CT angiography is a noninvasive assessment of coronary tree,whereas the analysis of the left ventricular parameters provides additional information of cardiac function without further radiation exposure or scan time,which can provide a more intuitive and system information for clinical.