Objective:To access the efficacy of monoenergetic imaging from spectral CT combined with metal artifact reduction for orthopedic implants (O-MAR) on reducing contrast hardening artifacts in the vein on the injection side, and determining the optimal monoenergetic spectral range to improve the display of axillary lymph node.Methods:A total of 35 patients with breast cancer who underwent chest-enhanced CT scans were enrolled in this retrospective study. The original data were reconstructed to obtain a total of 35 sets of images, including one conventional image, 17 groups of monoenergetic images, and 17 groups of monoenergetic+O-MAR images. The areas of interest were delineated in the high and low-density artifact area on the injection side of the same layer contrast agent, and the contralateral ectopectoralis. The CT value and its standard deviation (SD) were recorded respectively, the artifact area was measured, and the number of axillary lymph nodes was recorded. The difference in CT values (ΔCT 1, ΔCT 2) and the artifact index (AI1 and AI 2) of the high and low-density artifact areas relative to the contralateral ectopectoralis in the same layer were calculated respectively. Friedman test and Wilcoxon signed-rank test were used to compare the differences of ΔCT, AI, artifact area, and number of lymph nodes among the three imaging modalities, and the Kappa test was used to compare the differences in subjective evaluation. Results:As the energy level increased, compared to the conventional image, monoenergetic image, ΔCT 1 absolute value, ΔCT 2 absolute value, AI 1, and AI 2 showed a trend of initially low and then high, artifact area decreased, and the number of detected lymph nodes increased ( P<0.01). Compared to other energy levels, when the monoenergetic image was 100 keV, ΔCT 1 value, 140 keV for ΔCT 2 value, 120 keV for AI 1 value, and 130 keV for AI 2 value were close to zero, and the number of detected lymph nodes was highest at 110-200 keV. In contrast, in the monoenergetic+O-MAR images, ΔCT 1 absolute value showed a trend of initially low and then high, but, ΔCT 2 absolute value, AI 1, AI 2, and artifact area all significantly decreased, whereas the number of detected lymph nodes significantly increased (χ 2 values were 916.23, 895.93, 387.08, 519.41, 890.10, and 1027.98, respectively. All P<0.01). Compared to other energy levels, when the monoenergetic+O-MAR image was at 100 keV, ΔCT 1 value was close to zero, while ΔCT 2 value became close to zero with increasing energy level, and the number of detected lymph nodes was highest at 110-200 keV. As the energy level increased, the ΔCT 1, AI 1, AI 2, and artifact area of monoenergetic+O-MAR images were significantly smaller than those of monoenergetic images at the same energy level, and the number of detected lymph nodes was significantly higher than that of monoenergetic images ( P<0.01). The subjective scores for 110-200 keV monoenergetic images and 100-200 keV monoenergetic+O-MAR images were both higher than 4, and the score for monoenergetic+O-MAR images was significantly higher than that of single-energy spectrum images. The agreement between the two radiologists in assessing subjective scores was good. Conclusion:At 100-120 keV level, spectral CT monoenergetic combined with O-MAR imaging technique has the best performance in removing hardening-induced artifacts of chest-enhanced CT contrast agent and detecting and displaying axillary lymph nodes.

Objective:To explore the application effect of case-based learning (CBL) and lecture-based learning (LBL) in the teaching of image post-processing course in the standardized training system of medical imaging technology.Methods:A total of 34 trainees in the standardized training of imaging technology of Batch 2018 in West China Hospital of Sichuan University were divided into the experimental group and the control group according to their student numbers, with 17 students in each group. CBL teaching was carried out in the experimental group, and LBL teaching was carried out in the control group. According to the standardized training course design, after one year of image post-processing course teaching, the teaching effect was evaluated through closed-book examination, questionnaire survey and post-processing test. SPSS 20.0 was used for t-test and Mann-Whitney U test. Results:The scores of closed-book examinations (74.42±6.10) and post-processing test (73.47±6.03) in the experimental group were higher than those in the control group [(69.11±3.70) and (69.08±6.51)], and the difference was statistically significant ( P<0.05). The questionnaire survey showed that the students in the experimental group recognized CBL teaching in terms of learning interests stimulation, classroom atmosphere mobilization, clinical thinking cultivation, self-study ability training, and analysis of difficult and rare cases, etc. Conclusion:In the image post-processing course of standardized training of medical imaging technology, the rational application of CBL teaching mode is helpful to improve students' learning enthusiasm, self-learning ability, comprehensive analysis of clinical ability, practical ability, innovation consciousness and so on.

Combing with the professional characteristics of imaging technology, Radiological Department of West China Hospital, Sichuan University established the STAR training model for imaging technologists to cultivate the scientific research quality of young technicians, which includes sub-professional group training, tutor responsibility system, arrangement of research time, and reading-film session of technologists. Practice shows that this training model has made a series of achievements so far, such as that the number of publishing articles, funds application, authorized patents and oral presentation at international congress has been significantly increased. In addition, there is a high recognition of the STAR training model among young imaging technologists. Therefore, the STAR model can stimulate the scientific research passion of young technologists, and improve their scientific research capability.

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.

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.

Binding Sites ; Histone-Lysine N-Methyltransferase ; chemistry ; metabolism ; Histones ; chemistry ; metabolism ; Humans ; Methylation ; Multiprotein Complexes ; chemistry ; metabolism ; Nuclear Proteins ; chemistry ; metabolism ; Protein Binding ; Protein Conformation ; Yeasts ; chemistry

Objective To study the MR diffusion tensor imaging(MR-DTI) feature of optic atrophy.Methods Diffusion tensor imaging data of optic nerve were acquired in twenty patients with optic atrophy and 20 healthy subjects.Results ①Atrophic optic nerves were thin obviously on MRI,and the signal of atrophic optic nerves decreased markedly on fractional anisotropy(FA) map and directionally encoded color(DEC) map.②The FA value(0.277?0.078) and ?∥ value(1.808?0.307) of atrophic optic nerves were declined obviously,and mean diffusivity(MD) value(1.442?0.264) and ?⊥ value(1.231?0.225) increased obviously in comparison to the normal optic nerves,there were statistically significant differences between the patients and the volunteers(P