Objective To study the effects of joint optimization of CT scanning?modes and CTA starting?modes on the image quality, the patients' radiation doses and contrast volumes in cervicocerebral CTA. Method According to the date of examination from December 2013 to January 2014, 188 consecutive patients were prospectively selected and underwent cervicocerebral CTA using different CT scanning?modes and CTA starting?modes. These patients wererandomly divided into 4 groups:A1 (45 cases), A2 (48 cases), B1 (45 cases) and B2 (50 cases). Group A1 were Flash mode combined with test bolus, Group A2 were Flash mode combined with bolus tracking, group B1 were the common spiral scanning mode combined with test bolus and group B2 were the common spiral scanning mode combined with bolus tracking. The objective image quality evaluation criteria included the CT value comparison at the aortic arch (Pa1), carotid artery bifurcation (Pa2), basal artery (Pa3), superior vena cava (Pv1), internal jugular (pv2), transverse sinus (Pv3) and image objective noise. The subjective image quality assessments criteria included the contrast hardening artifact and diagnose acceptability. The radiation dose and contrast volumes of every patient were recorded and analyzed. The analysis of variance, the chi?square tests and the rank sum tests (Kruskal?Wallis) were used for data statistics. Results There were significant differences on the CT value at transverse sinus among the four groups, they were (124±30), (151±34), (130±37) and (160±37) HU, and different starting?modes had impacts on venous reflux (P<0.05), while scanning modes did not (P=0.162). There was no significant differences on the CT values at the other points among the four groups (P>0.05). The image noise had significant differences in four groups (P<0.05), the noise in Flash mode of dual?source CT were bigger than in the common spiral scanning mode. There was no statistically significant difference on diagnosis acceptability (P>0.05), however there were significant differences on contrast hardening artifacts (P<0.05) among the four groups. With the same scanning mode, the artifacts of group A1 were more serious than A2 and B1 were more serious than B2.There were significant differences on the patients' contrast volumes in the four groups (P<0.05), they were (45±5), (49±4), (35±4) and (35±4) ml, the contrast volumes in groups A1 and B1 were more than groups A2 and B2. There were significant differences among the four groups on patients' ED (P<0.05), which were (0.79 ± 0.07), (0.81 ± 0.08), (1.49 ± 0.11) and (1.51 ± 0.12) mSv. The radiation dose in groups A1, A2 were lower than those in B1 and B2. Conclusion The joint use of Flash mode and bolus tracking technique is recommended in application of cervicocerebral CTA, for its advantages of better image quality, good diagnosis acceptability, the patient's low radiation dose and low contrast volumes.

Objective To explore the effects of parent-adolescent conflict and cohesion on relational aggression among junior students.Methods Parent-adolescent Conflict Questionnaires,Parent-adolescent Cohesion Questionnaires,and the Relational Aggression Questionnaires were used in investigating 392 junior students.Results The level of relational aggression of junior students was low (22.52±5.15).There was no differences between relational aggression of male students (22.93± 5.43) and female students (22.00± 4.73) (P＞ 0.05),and of grade 1 students(22.72±5.14)and grade 2 students(22.64±5.67),grade 3 students(21.93±4.22) (P＞0.05).The students' relational aggression showed a significantly positive correlation with frequency and intensity of parent-adolescent conflict(r=0.269,r=0.307,r=0.268,r=0.271,P＜0.01),and negative correlation with father-adolescent cohesion(r=-0.171,P＜0.01).Parent-adolescent cohesion was negative predictor of relational aggression(β=-0.123,P＜0.05),and the intensity of parent-adolescent conflict was positive predictor(β=0.301,P＜0.01).Conclusion Parent-adolescent conflict and cohesion have significant effect on relational aggression among junior students.

Objective: To explore the effect and significance of medical dispute mediation committee as third party participating in pre - operative testimony mechanism. Methods: For 116 operations from Oct 2015 to May 2017, the medical dispute mediation committee as third party witnessed preoperative communication to patients and their families and signature, and we put forward suggestions for risk guarantee. Results: There were no medical disputes in any of the witness case, of which 43 cases purchased medical accident insurance and achieved risks transfer. Conclusion: Medical dispute mediation committee as third party participating in pre - operative testimony mechanism helps both doctors and patients clear risks, supervises the fulfillment of informed consent, promotes the landing of medical accident insurance, and achieves the recognition and transformation of medical risks.

Objective:To compare the difference between breast bracket combined with polyurethane foam and single polyurethane foam in the accuracy of immobilization, providing a better immobilization for breast cancer radiotherapy.Methods:Fifty breast cancer patients who received radiotherapy in Sun Yat-sen University Cancer Center from March 2021 to July 2021 were selected. Among them, 25 patients were immobilized with polyurethane foam (foam group), and the other 25 patients were immobilized with polyurethane foam combined with breast bracket (combination group). All patients were scanned by CBCT once a week to obtain setup errors in the SI, LR and AP directions for t-test. The formula M PTV=2.5 Σ+0.7 σ was used to calculate the margin of the planning target volume(M PTV). Results:The setup errors in the foam group were SI (2.0±3.26) mm, LR (0.88±2.76) mm, AP (1.22±3.55) mm, Rtn -0.24°±0.85°, Pitch 0.16°±1.11°, Roll -0.32°±1.05°, and the M PTV were 6.75 mm, 8.46 mm and 8.73 mm, respectively. The setup errors in the combination group were SI (1.0±3.01) mm, LR (0.62±2.74) mm, AP (1.82±3.21) mm, Rtn 0.64°±0.59°, Pitch 0.71°±1.22°, Roll 0.29°±0.73°, and the M PTV were 6.35 mm, 7.47 mm, and 7.61 mm, respectively. After comparing the setup errors in the three-dimensional directions between two groups, the t value of LR, SI, AP and Rtn, Pitch, Roll was -4.304, -2.681, 1.384, and -9.457, -3.683, -5.323, respectively. And the differences in the LR, SI, Rtn, Pitch and Roll directions were statistically significant (all P<0.05). Conclusions:The immobilization effect of polyurethane foam combined with breast bracket is better and the M PTV is also smaller than those of polyurethane foam alone. Therefore, it is recommended to use polyurethane foam combined with breast bracket for immobilization in breast cancer radiotherapy.