Objective To evaluate the clinical efficacy of artificial intelligence(AI)-assisted imaging diagnostic trials using multi-reader multi-case(MRMC)design,so as to provide a scientific basis for clinical evaluation of imaging diagnostic trials.Methods The MRMC design,widely used in imaging diagnostic trials,was adopted in this study.The Obuchowski-Rockette(OR)method of MRMC design was detailed,including model construction and test methods.A case study was conducted,collecting imaging data of 200 subjects from 3 hospitals,with 133 cases of rib fractures and 68 cases of non-rib fractures.Three radiologists reviewed all CT images of the subjects.The area under curve(AUC)value,sensitivity and specificity in detecting rib fractures between 2 reading modalities(radiologists with AI assistance vs radiologists reading independently)were compared.Results The AI-assisted reading group had an AUC value of 0.958,while the radiologist-independent reading group had an AUC value of 0.902,showing a significant difference(P＜0.001).The overall sensitivity and specificity of the AI-assisted reading group were 0.970 and 0.946,respectively;while the sensitivity and specificity of the radiologist-independent reading group were 0.838 and 0.966,respectively.The difference of sensitivity between groups was 0.131(95％confidence interval[CI]0.091-0.171),and the difference of specificity was-0.020(95％CI-0.059-0.020),indicating a significant difference in sensitivity but not in specificity between AI-assisted and radiologist-independent reading groups.Both groups had positive likelihood ratios(+LR)greater than 10 and negative likelihood ratios(-LR)less than 0.2,with positive predictive values approaching 1,suggesting that the diagnostic accuracy of the AI-assisted imaging diagnostic trials was high.Conclusion The AI-assisted reading method demonstrates a significant advantage in enhancing diagnostic efficiency,not only improving the diagnostic accuracy and detection rate of rib fractures,but also improving the work efficiency of radiologists and optimizing hospital services.

Objective To estimate the sample size of radiological diagnostic tests in multireader multicase(MRMC)design,and to explore the numbers of readers and cases under 3 different inference situations:random-reader random-case,fixed-reader random-case,and random-reader fixed-case.Methods The images of 114 participants(45 cases diagnosed as aortic coarctation by the gold standard)in the Van Dyke dataset were used,and 5 radiologists read these images under 2 different magnetic resonance imaging(MRI)sequences(Spin-echo and Cine MRI)to obtain the pre-experiment data.Then Obuchowski-Rockette method was used to estimate sample size.Results The mean area under curve(AUC)of aortic coarctation determined by radiologists was 0.941(95%confidence interval[CI]0.899-0.983)with the Spin-echo MRI sequence,and 0.897(95%CI 0.837-0.957)with the Cine MRI sequence.When the effect size was 0.044 and the number of readers was 5,we needed 337 participants for random-reader random-case,162 participants for fixed-reader random-case,and 282 participants for random-reader fixed-case.Conclusion In MRMC design,we need both the number of readers and cases;the larger the number of readers,the smaller the cases required.We need more samples under the situation of random-reader random-case,when the number of readers is≥5.

Objective:To investigate the level of self-management and daily physical activity in patients with type 2 diabetes mellitus (T2DM) of Zang and Han nationalities in Tibetan, China, and to compare the difference in daily management between T2DM patients of Zang and Han nationalities, to develop reasonable and effective chronic disease management strategies for long-term out-of-hospital management of T2DM patients of Zang nationalities.Methods:A total of 265 T2DM patients with glycosylated hemoglobin (HbA1c) ≥ 7% who were admitted to the Endocrinology Ward of the Hospital of Chengdu Office of People's Government of Tibet Autonomous Region from November 2020 to April 2021 and who were from different regions of Tibet were included in this study according to inclusion and exclusion criteria. The general data of all included patients were collected. Glucose and lipid metabolism-related indicators were determined. The Generalized Diabetes Self-Management Efficacy Scale and International Physical Activity Questionnaires (IPAQ) were used to evaluate patients' levels of self-management and daily physical activity.Results:The hemoglobin level in T2DM patients of Zang nationality was (154.09 ± 24.11) g/L, which was significantly higher than that in T2DM patients of Han nationality ( P < 0.05). The total cholesterol, fasting blood glucose, and low-density lipoprotein in T2DM patients of Zang nationality were (4.63 ± 1.41) mmol/L, (7.94 ± 2.19) mmol/L, and (2.75 ± 1.11) mmol/L, respectively, which significantly higher compared with T2DM patients of Han nationality (all P < 0.05). Compared with T2DM patients of Han nationality, T2DM patients of Zang nationality had lower self-management scores (81.40 ± 15.44) points, diet control scores (17.26 ± 4.97) points, physical exercise scores (11.67 ± 4.42) points, prevention and treatment of high and low blood sugar score (12.21 ± 5.72) points. The differences were statistically significant (all P < 0.05). Moderate-intensity physical activity was a significant difference between T2DM patients of Zang and Han nationalities ( P < 0.05). Conclusion:Compared with T2DM patients of Han nationality, T2DM patients of Zang nationality have lower overall self-management levels, including diet control, physical exercise, prevention and management of high and low blood glucose, and moderate-intensity physical activity. Targeted individualized education should be carried out according to the Tibetan cultural characteristics, to further develop an intervention method and an out-of-hospital management strategy for chronic disease, which are suitable for T2DM patients of Zang nationality.

Objective To analyze the clinical, imaging characteristics and NOTCH3 mutations of cerebral autosomal dominant arteriopathy with the subcortical infarcts and leukoencephalopathy (CADASIL) in Henan, China.Methods CADASIL patients diagnosed by gene or biopsy in People′s Hospital of Zhengzhou University between 2012-2016 were recruited.Clinical and imaging features of these patients were analyzed retrospectively.The distribution of NOTCH3 gene mutations hotspots was described in Henan region at the same time.Results There were 37 patients from 19 families who were diagnosed as CADASIL by genetic testing or biopsy, 27 of whom had symptoms of CADASIL.Two families were confirmed by pathological examination and 17 by genetic testing.Of these 17 families, 13 mutations were found.Mutations in exon 11 were found in eight families, in exon 4 were detected in four families, and in exon 13 were found in two families.Mutation in exons 3, 8 and 20 was detected in one family respectively.Most patients presented with stroke and several presented with cognitive decline.Twelve patients had been attacked by risk factors.Magnetic resonance imaging (MRI) was performed on 22 patients.White-matter lesions were distributed in brain stem, basal ganglia, subcortical, temporal pole, external capsule.There were 19 patients with white-matter lesions in temporal pole and seven in capsula externa, showed as a high signal in T2WI.Conclusions CADASIL patients can be associated with risk factors.T2WI hyperintensities in the anterior temporal lobe were more common than that in the capsular external.Exon 11 and exon 4 were the hotspots for the NOTCH3 mutation in Henan patients.

Before and after zinc and micro-nutrients supplement the changes of intelligence and growth in 108 healthy children aged 7～8yrs were studied.The children were randomly divided into 3 groups:zinc supplement(Z),zinc+micronutrients supplement(Z+M),and micronutrients supplement(M),Before the supplements,hair Zn contemt of children was 2 28?0 74?mol/g and 22 22% of the hair Zn content was lower than 1 68?mol/g?There was a positive correlation between intelligence quotient(IQ) and hair Zn content .After supplement,there were no significant changes among the 3 groups on hair Zn content .The changes of IQ and cognition in Z+M group and M group were significantly higher than Z group,and there was no significant difference between Z+M group and M group.The change of knee height in Z+M group was markedly higher than M group and Z group,while M group was sgnificantly higher than Z group.The results demonstrated that zinc deficiency might not be the main factor that affects the intelligence and growth children,perhaps other micronutrients deficiency should be paid more attention.The simultaneous supplement of zinc and micronutrients may promote the intelligence and growth of children.