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Objective:To synthesize non-contrast-enhanced CT images from enhanced CT images using deep learning method based on convolutional neural network, and to evaluate the similarity between synthesized non-contrast-enhanced CT images by deep learning(DL-SNCT) and plain CT images considered as gold standard subjectively and objectively, as well as to explore their potential clinical value.Methods:Thirty-four patients who underwent conventional plain scan and enhanced CT scan at the same time were enrolled. Using deep learning model, DL-SNCT images were generated from the enhanced CT images for each patient. With plain CT images as gold standard, the image quality of DL-SNCT images was evaluated subjectively. The evaluation indices included anatomical structure clarity, artifacts, noise level, image structure integrity and image deformation using a 4-point system). Paired t-test was used to compare the difference in CT values of different anatomical parts with different hemodynamics (aorta, kidney, liver parenchyma, gluteus maximus) and different liver diseases with distinct enhancement patterns (liver cancer, liver hemangioma, liver metastasis and liver cyst) between DL-SNCT images and plain CT images. Results:In subjective evaluation, the average scores of DL-SNCT images in artifact, noise, image structure integrity and image distortion were all 4 points, which were consistent with those of plain CT images ( P>0.05). However, the average score of anatomical clarity was slightly lower than that of plain CT images (3.59±0.70 vs. 4) with significant difference ( Z = -2.89, P<0.05). For different anatomical parts, the CT values of aorta and kidney in DL-SNCT images were significantly higher than those in plain CT images ( t=-12.89, -9.58, P<0.05). There was no statistical difference in the CT values of liver parenchyma and gluteus maximus between DL-SNCT images and plain CT images ( P>0.05). For liver lesions with different enhancement patterns, the CT values of liver cancer, liver hemangioma and liver metastasis in DL-SNCT images were significantly higher than those in plain CT images( t=-10.84, -3.42, -3.98, P<0.05). There was no statistical difference in the CT values of liver cysts between DL-SNCT iamges and plain CT images ( P>0.05). Conclusions:The DL-SNCT image quality as well as the CT values of some anatomical structures with simple enhancement patterns is comparable to those of plain CT images considered as gold-standard. For those anatomical structures with variable enhancement and those liver lesions with complex enhancement patterns, there is still vast space for DL-SNCT images to be improved before it can be readily used in clinical practice.
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Objective To investigate the association between the single nucleotide polymorphisms (SNPs) rs894278 and rs11931074 of α-synuclein (SNCA) and non motor symptoms in Parkinson' s disease (PD).Methods One hundred and twenty PD patients and 100 healthy controls enrolled from Tonglu Hospital Affiliated to Ruijin Hospital and Ruijin Hospital,Shanghai Jiaotong University School of Medicine from 2012 to 2014 were recruited and the motor subscale of the Unified Parkinson' s Disease Rating Scale Ⅲ (UPDRS-Ⅲ) was used to evaluate motor function.The Mini-Mental State Examination (MMSE),17-item Hamilton Rating Scale (HAMD-17),the Rapid Eye Movement Behavior Disorder Screening Questionnaire (RBDSQ) and the ROME-Ⅲ criteria for chronic constipation were used to evaluate non motor symptoms.SNCA SNPs (rs894278,rs11931074) were genotyped by direct sequencing.Results There was no statistically significant difference in age,sex,non motor symptoms scores among the three genotypes of the two SNPs in control group.There was no statistically significant difference in age,sex,UPDRS-Ⅲ scores and Hoehn-Yahr stage among the three genotypes of the two SNPs in PD group.The results demonstrated that there was no association between the two SNPs and RBDSQ scores,HAMD-17 scores,MMSE scores and constipation in PD patients.However,additional analysis showed that patients with GG rs894278 had a greater proportion of clinical probable RBD than those with GT and TT types (GG 52.2％,12/23;GT 18.2％,10/55;TT 21.4％,9/42;x2 =9.254,P=0.002;x2 =6.424,P=0.005).In Logistic regression analyses adjusting for age and sex,we observed that rs894278 GG genotype could increase the risk of RBD in PD patients (OR =5.367,95％ CI =1.607-17.925,P =0.006).There was no association of RBD with allelic and genotypic distributions of SNCA rs11931074.Conclusion The results indicate that the rs894278 polymorphism correlates with RBD,while rs11931074 does not.
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Objective To investigate the relationship between apparent diffusion coefficient (ADC)value of rectal adenocarcinoma on DWI and its pathological grading.Methods The ADC values of 46 rectal adenocarcinomas were measured and compared with their histopathological grades.Results The 46 rectal adenocarcinomas included well differentiated adenocarcinomas in 14,moderate-ly differentiated ones in 20,and poorly differentiated ones in 12.The ADC values of well,moderately and poorly differentiated ade-nocarcinomas were (1.125±0.103)×10 -3 mm2/s,(1.030±0.098)×10 -3 mm2/s and (0.922±0.091)×10 -3 mm2/s,respective-ly,exhibiting a statistical difference (χ2 =1 7.35 1,P =0.000).Mann-Whitney U test showed that difference in ADC value between different histopathological grades was statistically significant.Conclusion ADC value of rectal adenocarcinoma can be used as a bio-marker for cell grading to guide treatment decision and prognosis assessment.