Objective To evaluate the application of measurement of T2*value,width of substantia nigra pars compacta (SNc) and the ratio of the width to the midbrain diameter in diagnosing Parkinson disease (PD) in early stage with susceptibility weighted imaging ( SWI) by 3T MR. Methods 59 patients with early stage idiopathic PD patients and 59 healthy controls,ranging in same ages and gender,had been scanned with routine sequences and SWI sequences by 3T MR. T2*value,width and the ratio of the width to the midbrain diameter of SNc were measured. The results of measurement were analyzed and compared. Results (1) The T2*values, width and the ratio of the width to the midbrain diameter was decreased in homolateral side SNc of symptoms of subjects with PD compared with the healthy controls ( <0.05) . (2) There was a significant reduction in the T2*values and the ratio of the width to the midbrain diameter in contralateral side SNc symptoms of subjects with PD compared with the healthy controls (P<0.05) . There was no differences in width of SNc ( >0.05) . Conclusion Measurement of T2*value, width and the ratio of the width to the midbrain diameter of SNc with SWI is reliable to diagnose PD.

Objective To evaluate MRI diagnostic value for single lesion characteristics in the splenium of corpus callosum.Methods MRI features,clinical data,and parts of follow-up results of 9 cases with single lesion in the splenium of corpus callosum were analyzed retrospectively.Results (1)Clinical manifestations:headache and dizziness occurred in 4 cases,syncope in 3 cases,fever in 2 cases, physical activity barriers in 2 cases.(2)Clinical diagnosis:hypoglycemic encephalopathy were rescaned one month later in 3 cases, in which the previous lesion completely disappeared.Clinical experience of encephalitis were improved after treatment in 2 cases. Cerebral infarction,epilepsy,brain injury and degeneration were diagnosed respectively in each one case,in which lesion still existed after treatmented.(3)Image findings:despite the different clinical manifestations,image features of all cases were quite similar. Round or foliated like lesions of slightly long T1 and long T2 signals in the splenium of corpus callosum were presented in all cases. High signals on diffusion weighted imaging and low signals on the ADC were showed with same lesions,andno obvious enhancement after contract media injected was seen.Conclusion Single lesions in the splenium of corpus callosum are showed in many diseases. The image features of hypoglycemic encephalopathy or encephalitis have certain characteristics (single lesion is reversible).Accurate diagnosis need to combine with clinical data and medical history.

Objective To explore the feasibility of differential diagnosis of Gleason score (GS)(3+4)and (4+3)in prostate cancer (PCa) based on texture parameters of T2 WI and ADC maps.Methods A total of 77 patients with GS 7 points in PCa confirmed by pathology were enrolled in this retrospective study,including 45 GS(3+4)cases and 32 GS(4+3)cases.ROI was manually drew on the largest section of tumor on the axial T2 WI and ADC maps,and five texture parameters were extracted,namely,angular second moment (ASM),contrast, correlation,inverse difference moment and entropy,and the texture parameters between groups were analyzed statistically,then ROC curve was used to evaluate the diagnostic efficiency of texture parameters with statistical differences.Results There was no significant difference in age and prostate specific antigen (PSA)between GS (3 + 4)and GS (4 + 3)groups (P＞0.05).There were significant differences in ASM and entropy between T2 WI and ADC (P＜0.05),but there was no statistical difference in contrast,correlation and inverse difference moment (P＞0.05).Except for the AUC of T2 WIASM,there were statistical differences among T2 WIentropy ,ADCASM and ADCentropy.The AUC of ADCASM and ADCentropy were larger than that of T2 WIASM and T2 WIentropy.The AUC of ADCentropy had the largest AUC (0.732),the cut off value was 5.71 ,with the sensitivity was 97.6% and specificity was 5 9.5%.Conclusion MRI texture analysis can be used to differentiate GS (3 + 4)from GS (4 + 3)in PCa,and the ADCentropy have the best diagnostic efficacy.