Objective Using 3.0T magnetic resonance imaging and diffusion tensor magnetic resonance imaging, quantitative analysis of nerve fibers in region of interest was conducted in patients with psychosis associated with parkinson disease (PDPsy), PD patients without psychotic symptoms and normal control group, then investigate the relationship between FA value change in the region of interest and PDPsy, and the pathogenesis of PDPsy. Methods Sixteen patients with PDPsy, 24 PD patients without psychotic symptoms and 20 healthy persons with the corresponding age and sex (normal control group) were enrolled in this study. The patients with PDPsy and patients without psychotic symptoms have the matched gender, age and disease duration. All patients were underwent routine MR plain scan and DTI scan. The FA graph was reestablished, and the FA values of the bilateral substantia nigra-striatum fiber loop through the site (substantia nigra, red nucleus, nucleus, globus pallidus), frontal, occipital lobe and cingulate associated with schizophrenia were statistical analyzed. Results The nigral FA values in PDPsy and PD groups were significantly lower than that in control group. The frontal lobe and occipital lobe FA values in PDPsy group were significantly lower than those in control group. The frontal lobe, occipital lobe and cingulate FA values in PDPsy group were lower than those in PD group, but there were no significant differences between the two groups. The frontal lobe and occipital lobe FA values in PD group were lower than those in the control group, but there were no significant differences between the two groups. Conclusion DTI is a noninvasive and quantitative measurement for FA values of various brain regions in patients with PDPsy. It can reveal the PDPsy corresponding neural loop changes at the molecular imaging level, and can provide more information for the pathogenesis and clinical manifestations of PDPsy.

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:In order to improve medical undergraduates' ability to interpret medical images and clinical application competencies, this study aimed to explore the effects of case-based learning (CBL) combined with seminars for integrated medical imaging teaching as well as its application value.Methods:We assigned 40 medical undergraduates of grade 2016 of Chongqing Medical University to learn imaging of liver diseases using either a traditional teaching model (control group, n=20) or the combined teaching model (experimental group, n=20), in the form of classroom teaching in our hospital. The teaching effects were evaluated through a theoretical assessment, image reading assessment, and questionnaire survey. SPSS 23.0 software was used for statistical analysis. Continuous data were compared using the t test, and categorical data were compared using the chi-square test. Results:The total theoretical score and total image reading score of the experimental group were (76.35±8.63) and (79.80±10.60), respectively, which were significantly higher than those of the control group ( P<0.05). Specifically, for the experimental group, the scores of theoretical analysis and comprehensive application were (22.85±3.63) and (22.15±2.92), respectively; the scores of image interpretation and report writing were (48.55±6.81) and (31.25±4.15), respectively; the scores for medium questions and hard questions in the image reading test were (24.85±3.12) and (22.50±2.91), respectively; and the pass rate and excellence rate for image reading were 100.00% and 50.00%, respectively, all significantly higher than those of the control group ( P<0.05). The degree of satisfaction with teaching in the experimental group was significantly higher than that of the control group ( P<0.05). In terms of improving learning desire, independent learning ability, innovation and expansion ability, literature search ability, communication and collaboration ability, and image interpretation ability, the experimental group showed significantly higher self-evaluated scores than the control group ( P<0.05). Conclusions:The CBL+seminar model can effectively improve students' academic performance in theoretical and image reading assessments, strengthen their ability to analyze and solve difficult problems, increase their enthusiasm and initiative in learning, and improve their comprehensive quality and image interpretation competency, which is worth promotion and application.