Résumé
Objective:To evaluate the clinical application of three dimensional artificial intelligence(3D-AI) localization technology in chest CT scan.Methods:A total of 100 patients who underwent chest CT for COVID-19 screening in Nanjing University Medical School Affiliated Drum Tower Hospital were collected from September 2020 to October 2020 were analyzed retrospectively. The patients were divided into manual positioning group ( n=50) and 3D-AI automatic positioning group ( n=50) with block randomization method. All patients were scanned with the same CT scanning protocol. The off-center distance, CT dose index (CTDI), dose length product (DLP) and CT examination time were measured and recorded. Quantitative image evaluation of mediastinal window images and qualitative image evaluation of chest window images were assessed by two radiologists. The off-center distance, CTDI, DLP, CT examination time and objective indexes of image quality of two groups were compared by independent sample t test. The quantitative image quality scores were compared with χ 2 test. Results:Compared with manual positioning group, the overall off-center distance of 3D-AI automatic positioning group was reduced by 42.86% [(15.4±9.7) vs. (8.8±7.2)mm, t=3.65, P<0.01], CTDI was reduced by 10.67%[(7.5±2.5) vs. (6.7±2.6)mGy, t=0.59, P=0.04], DLP was reduced by 13.33%[(270±95) vs. (234±86)mGy·cm, t=1.98, P=0.02], the average examination time was reduced by 29.91% [(214±26) vs. (150±14)s, t=15.79, P<0.01]. There were no significant differences in the background noise, signal to noise ratio of descending aorta and erecting spinal muscle, and subjective score between two groups ( P>0.05). Conclusion:The 3D-AI automatic positioning technology can greatly improve the accuracy of patient positioning and reduce the radiation dose for chest CT imaging, and improve work efficiency with qualified chest CT image quality.
Résumé
AIM: To explore the effect of L-arginine (L-Arg) on the arrhythmia induced by ischemia/reperfusion (IR) of the right coronary artery in rabbits. METHODS: 48 healthy adult rabbits were divided into 4 groups (n=12 of each) randomly: IRa group (120 min reperfusion after 30 min ischemia), IRb group (120 min reperfusion after 120 min ischemia), IRa+L-Arg group and IRb+L-Arg group. I/R model was established by occluding and loosening the root of the right coronary artery in rabbits. The changes of ECG and arrhythmia were recorded and graded. RESULTS: ① The longer time of IR was, the higher the score of the arrhythmia was found. The incidence of atrial-ventricular block (AVB), sinus-atrial block (SAB), even sinus arrest were detected and aggravated gradually. ② The incidence of AVB was decreased and from Ⅲ?→Ⅱ?→Ⅰ? markedly, some of sinus and atrial arrhythmia were transformed into sinus rhythm gradually, and all of the arrhythmia scores in IRa group were decreased significantly as compared with the same time phases of IRb group (P
Résumé
AIM: To investigate the influence of laminin (LN) on the expression of bcl-2 in rabbit cornea endothelial cells. METHODS: Cultured rabbit corneal endothelial cells were divided into three groups: normal control group, LN group and negative control group. Immunohistochemical technique and ELISA were used to measure the staining and A value to assess the levels of bcl-2 expression. RESULTS: Bcl-2 expression score showed that LN group had a strong positive expression. Control group only showed a weak expression. Negative control group showed a negative expression by immunohistochemical staining. The mean A value of each group were 1.21?0.18 (LN group), 1.05?0.14 (normal control group) and 0.04?0.01 (negative control group). CONCLUSION: LN promotes bcl-2 gene expression in rabbit cornea endothelial cells, and protects the cells from apoptosis.