Objective To explore the clinical application value of second-generation dual-source CT combined with intelligent modulation and iterative reconstruction in emergency aortic dissection imaging.Methods A total of 40 emergency patients with clinical suspected aortic dissection were included in this study.Conventional scanning was performed in the control group,and large-pitch intelligent modulation and iterative reconstruction were performed in the test group.The mean CT value,mean noise,signal noise ratio(SNR),contrast noise ratio(CNR),effective dose,image quality and aortic root image quality were evaluated and analyzed.Results Totally 40 patients successfully completed CT aortic dissection imaging.There was no difference in image quality between the two groups (P＞ 0.05).The quality of aortic root images in the test group was better than that in the control group,and the difference was statistically significant(x2=22.556,P＜0.05).The mean CT value and mean noise of aorta in the control group were slightly higher than those in the test group.However,SNR and CNR in the test group were higher than those in the control group,and the difference was statistically significant (t =-21.042,-15.924,8.530,11.495,P＜0.05).The effective dose of the control group [(10.59±3.89)mSv] was significantly higher than that [(6.39±0.81) mSv] of the test group,the difference was statistically significant (t =-12.327,P＜0.05).Conclusions The combined intelligent modulation technique and iterative reconstruction technique with dual-source CT large pitch scanning can meet the requirements of image quality and reduce the effective dose,and can be used as a conventional imaging method for emergency CT of aortic dissection.

Objective: To develop the Adolescent Mental Health Literacy Assessment Questionnaire (AMHLAQ), and to evaluate its reliability and validity among undergraduates. Methods: On the basis of the definition of mental health literacy (MHL) and the Knowledge, Attitudes and Practices (KAP) theory, this study constructed a total of 36 items consisting of four dimensions, and scores were measured according to a five point Likert type scale. Using a cluster sampling method, a questionnaire survey was conducted among 3 826 freshmen and sophomore students from two medical schools in Anhui Province. The items were screened by performing t tests, Pearson s correlation coefficient analysis and factor analysis. The reliability and validity of the questionnaire were evaluated using indicators including homogeneity reliability, the split half reliability coefficient, and construct validity. Results: Factor analysis revealed that the AMHLAQ consisted of 22 questions grouped into four domains. The variance cumulative contribution rate was 62.213%. The reliability result showed that the Cronbach s alpha coefficient of the total questionnaire was 0.897, the split half reliability was 0.800, the Cronbach s coefficient of each dimension was 0.796 to 0.885, the split half reliability of each dimension was 0.725 to 0.846, and the indicators had a high level of reliability. Confirmatory factor analysis showed that the model fit was good ( χ 2/df =19.319, P <0.01; RMSEA=0.069). Conclusion AMHLAQ is consistent with the evaluation standard of psychometrics, has good reliability and validity, and can be used to estimate the level of MHL among undergraduates.