Objective To explore the application value of ECG tube current modulation technology of dual source CT in coronary angiography,compared with retrospectively ECG-gated technique.Methods 200 patients were randomly divided into ECG tube current modulation group (Group A)and retrospectively ECG-gated group(Group B).In Group A,the main parameters were the exposure time windows of full dose,which were set according to different heart rates.χ2 test was adopted in the subjective score,and t test was used in the objective score and radiation dose.Results There was no statistical significance in image quality between the two groups(χ2 =2.125,tnoise =-0.557,P >0.05 );The effective dose (ED)of Group A and Group B were (3.30±0.40)mSv and(6.90±1.76)mSv,respectively.The difference was statistically significant (t ED =-1 9.954,P <0.05).The radiation dosage of Group A was 52% lower than that of Group B.Conclu-sion Compared with retrospectively ECG-gated technique,the ECG tube current modulation technique ensures the image quality, and at the same time it can significantly reduce the radiation dose,therefore,it can be used as a routine examination technique of cor-onary angiography.

Clinical practice of medical imaging technology undergraduates is a key link in the transformation from imaging technology students to imaging technologists. However, there are a series of problems leading to poor practice effect, e.g., imaging technology involves a lot of learning contents, and the teachers' level is uneven. Based on the above problems, some improvements have been implemented, including the establishment of the admission lecture system and tutor responsibility system, application of pluralistic teaching methods, standardizing the examination system of interns, flexible adjustment of practice time arrangements, training of practice teaching team, and so on. Finally, the quality and effect of undergraduate practice teaching in medical imaging technology has been improved significantly.

Objective To evaluate the effect of 131 iodine(131I) therapy in medium and large goiter with hyperthyroidism in order to investigate the influence of pretreatment with antithyroid drugs (ATD) methimazole(MMI) and propylthiouracide (PTU) on 131I therapy.Methods A total of 338 hyperthyroidism patients (136 cases for male,202 cases for female) with thyroid mass greater than 40 grams were treated with 131I in the People's Hospital of Sichuan Province.Thyroid function,thyroid 131I uptake ratio and thyroid imaging were measured before treatment were measured 1-3 months later after administration of 131I,and they were followed up for 6 months to 4 years.Results There were statistical difference between pretreatment and 3 months later of 131I therapy in terms of free triiodothyronine (FT3),(Free thyroxine) FT4.The level of FT3 decreased from (31.9 ± 16.2) pmol/L to (7.8 ±8.5) pmol/L(t =23.9,P =0.000) and level of FT4 decreased from (58.8 ± 22.2) pmol/L to (19.4 ± 16.9) pmol/L(t =25.4,P =0.000).Among 338 patients,109 patients (32.2％) were developed hypothyroidism,and 91 patients (26.9％) were cured,91patients (26.9％) with improved state,20 patients(5.9％) with ineffective and 27 patients(8.0％) with relapse after administration of 131I.The total effective rate was 94.1％ (318/338).Thyroid weight,levels of FT3,FT4,thyroglobulin antibody(TGA),thyroid microsomal antibody(MCA) in effective group were (49.8 ± 9.97) g,(32.5 ± 16.3) pmol/L,(59.5 ± 22.2) pmol/L,(43.6 ± 35.3) ％,(30.1 ± 22.6) ％ respectively,and were (56.9±15.7) g,(22.8 ± 12.8) pmol/L,(47.9 ±20.3) pmol/L,(22.8±30.0)％,(15.3 ±20.5)％ respectively in ineffective group.There were statistically significant differences between the ineffective group and effective group (t =2.932,2.602,2.287,2.501,2.766 ; P =0.000,0.010,0.023,0.013,0.006).Logistic regression analysis was showed that weight of thyroid and serum FT3 were the most important factors in affecting 1131 therapy.Conclusion 131 I therapy for medium and large-sized goiter with hyperthyroidism is safe and effective.ATD may not reduce the effectiveness of subsequent 131I of hyperthyroidism.Thyroid weight and FT3 are the key influential factors in affecting 131I.

Objective:To investigate the value of combined serum thymidine kinase 1(S-TK1)and thyroglobulin(Tg)detection in the differential diagnosis of benign and malignant thyroid nodules.Methods:S-TK1 and Tg levels were retrospectively detected with an en-hanced chemiluminescence dot blot assay and chemiluminescence immunoassay in 81 cases of malignant thyroid nodules,62 cases of benign thyroid nodules,and 40 cases of normal controls in the Sichuan Academy of Medical Sciences&Sichuan Provincial People's Hospital,between October 2015 and September 2017.To compare the S-TK1 and Tg levels in each group,and to evaluate the clinical value of detecting S-TK1 and Tg,in the differential diagnosis of benign and malignant thyroid nodules,Logistic regression and Receiver Operating Characteristic Curve (ROC) were performed. Results: The S-TK1 and Tg levels in patients with malignant thyroid nodules [(5.33±3.38)pmol/L,(61.86±24.80)ng/mL]were significantly higher than in those with benign nodules[(1.40±0.99)pmol/L,(45.13± 15.80)ng/mL]and in normal controls[(1.35±0.41)pmol/L,(40.88±15.45)ng/mL](P<0.05).The ROC of S-TK1,Tg,and P of the regres-sion equation showed that the S-TK1 and Tg cut-off values were 2.320 pmol/L and 63.40 ng/mL,respectively.The area under the curve (AUC),sensitivity,and total effective rate of S-TK1 were significantly higher than those of Tg(P<0.05).The cut-off value of P was 0.372, and the AUC,sensitivity,and total effective rate were significantly higher than those of S-TK1 and Tg(P<0.05).Conclusions:S-TK1 was indicative than Tg in the differential diagnosis of benign and malignant thyroid nodules.The combined detection of S-TK1 and Tg can significantly improve the sensitivity and total effective rate of diagnosis,and as such,the combined detection of both parameters can assist the differentiation of benign and malignant thyroid nodules.

Objective:To explore the efficiency of MR psychoradiology examination in screening and classification of psychiatric disorders as well as its potential clinical application.Methods:Retrospective study was conducted for 144 patients with MR psychoradiology examination, who were diagnosed mental disorders based on International Statistical Classification of Diseases and Related Health Problems Tenth Revision (ICD-10) from September 2018 to July 2020 in West China Hospital of Sichuan University. As our previous studies, imaging diagnostic models were constructed based on gray matter volume (GMV) analysis for four kinds of psychiatric disorders, including depression, anxiety disorder, bipolar disorder and schizophrenia. For 120 patients with psychiatric disorders, the GMV change pattern of brain regions was detected and subtyped by MR psychoradiology examination with 50% similarity threshold of the above imaging diagnostic models. The diagnostic efficiency of MR psychoradiology examination was evaluated with references of clinical diagnose. For 24 patients with dementia, brain atrophy was additionally measured by conventional MR examination and MR psychoradiology examination respectively.Results:The sensitivity, specificity, Youden index and accuracy of MR psychoradiology in identifying the four psychiatric disorders were 86.6% (84/97), 69.6% (16/23), 0.56 and 83.3% (100/120), including depression [77.8% (28/36), 69.0% (58/84), 0.47, 71.7% (86/120)], schizophrenia [58.8% (10/17), 91.3% (94/103), 0.50, 86.7% (104/120)], bipolar disorder [42.1% (8/19), 96.0% (97/101), 0.38, 87.5% (105/120)] and anxiety disorder [24.0% (6/25), 100% (95/95), 0.24, 84.2% (101/120)]. As for 24 patients with dementia, 58.3% (14/24) were detected with brain atrophy by conventional MR examination, while 91.7% (22/24) were detected by MR psychoradiology examination.Conclusions:MR psychoradiology can detect the subtle brain structural abnormalities of patients with mental disorders. Although it can′t be used as an independent biomarker for disease diagnosis till now, it is of great help in improving the accuracy and objectivity of diagnosis.

The Department of Radiology of West China Hospital of Sichuan University provides us a teaching model that image-reading combined with problem-based learning (PBL) for radiographer once a month. Based on the problem images and typical cases, after careful image-reading, radiographer is guided to think positively and propose specific solutions to the problems. Then designated personnel gives a detail lecture on related diseases, imaging performance, diagnostic requirements, conventional scanning schemes, operating specifications, common problems and image post-processing, etc., which aims at taking continuing education for radiographers.

Objective:To explore the application effect of case-based learning combined with problem-based learning teaching model in refresher training of medical imaging technologists.Methods:The study recruited 46 imaging technologists trained in radiology department in the Batch 2017 and Batch 2018 of West China Hospital of Sichuan University. They were divided into 2 groups: experimental group (23 persons) and control group (23 persons). Case-based learning combined with problem-based learning teaching method was used in the experimental group, and traditional lecture-based learning method was used in the control group. 2 test was used for sex distribution comparisons between the two groups, and independent t test was conducted to compare the differences in age, working years, entrance examination results, attitude rating scores, stage examination scores, completion examination scores, and operational examination scores between the two groups. Mann-Whitney U test was used for comparisons of non-parametric variables between the two groups, such as qualifications, occupation title, and questionnaire results.Results:Theoretical examination results at the second stage, the third stage, completion and operational examination results in the experimental group were higher than those in the control group [(91.17±2.59) vs. (85.26±3.03), (92.00±1.86) vs. (87.43±3.23), (92.39±2.08) vs. (87.04±2.93), (85.70±5.48) vs. (80.87±5.57), P<0.05]. The questionnaire survey showed that the stimulation of subject interest, the cultivation of exploration spirit, the exercise of self-learning ability, the establishment of clinical ideas, the analysis of difficult problems, the mastering of practical operations, and the affirmation of self-worth in the experimental group were better than those in the control group, with significant difference [4(3, 4) scores vs. 3(2, 3) scores, 4(3, 4) scores vs. 2(2, 3) scores, 3(3, 4) scores vs. 2(2, 3) scores, 3(3, 4) scores vs. 3(2, 3) scores, 3(3, 4) scores vs. 2(2, 3) scores, 4(3, 4) scores vs. 3(2, 3) scores, 4(3, 4) scores vs. 3(2, 3) scores, P<0.05], while the consolidation of theoretical knowledge of the experimental group was not different from the control group [3(2, 3) scores vs. 3(2, 3) scores, P>0.05]. Conclusions:The reasonable application of case-based learning combined with problem-based learning teaching model in refresher training of medical imaging technologists is helpful to improve their learning enthusiasm, self-learning ability, clinical analysis ability, practical operation ability, and long-term consolidation of theoretical knowledge, and it also can contribute to affirmation of self-worth.

Objective:To explore the application effect of case-based learning (CBL) combined with problem-based learning (PBL) teaching model in refresher training of medical imaging technologists.Methods:The study recruited 46 imaging technologists trained in radiology department in the Batch 2017 and Batch 2018 of West China Hospital of Sichuan University. They were divided into 2 groups: experimental group (23 persons) and control group (23 persons). CBL combined with PBL teaching method was used in the experimental group, and traditional lecture-based learning (LBL) method was used in the control group. The results of attitude evaluation, staged exminations, graduation assessment and operational skill tests were compared between the two groups, and the questionnaire survey was performed to test the affirmation of self-worth of the two groups of interns. SPSS 17.0 was used for chi-square test, independent t test, and Mann-Whitney U test. Results:Theoretical examination results at the second stage, the third stage, completion and operational examination results in the experimental group were significantly higher than those in the control group [(91.17±2.59) vs. (85.26±3.03), (92.00±1.86) vs. (87.43±3.23), (92.39±2.08) vs. (87.04±2.93), (85.70±5.48) vs. (80.87±5.57), P<0.05]. The questionnaire survey showed that such 7 aspects as the stimulation of subject interest, the cultivation of exploration spirit, the exercise of self-learning ability, the establishment of clinical ideas, the analysis of difficult problems, the mastering of practical operations, and the affirmation of self-worth in the experimental group were better than those in the control group, with significant difference ( P<0.05), while the consolidation of theoretical knowledge of the experimental group was not statistically different from the control group ( P>0.05). Conclusion:The reasonable application of CBL combined with PBL teaching model in refresher training of medical imaging technologists is helpful to improve their learning enthusiasm, self-learning ability, clinical analysis ability, practical operation ability, and long-term consolidation of theoretical knowledge.