Objective To explore the application value of the"triple-low"(low radiation dose,low contrast medium and low con-trast flow rate)technique combined with the artificial intelligence iterative reconstruction(AIIR)in craniocervical computed tomo-graphy angiography(CTA).Methods Seventy patients undergoing head and neck CTA were prospectively enrolled and randomized into group A and group B,with 35 patients in each group.Group A was the"triple-low"technique group(80 kV,0.4 mL/kg,2.5 mL/s);group B was the control group(120 kV,0.7 mL/kg,5 mL/s).Group A images used AIIR and hybrid iterative reconstruction(HIR),and obtained group A1 and group A2;group B images used HIR.CT values,standard deviation(SD)values,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)at the level of the aortic arch,common carotid artery bifurcation,internal carotid artery segment C3 and middle cerebral artery segment M1 in the three groups of CTA images were measured and analyzed.The radiation dose and contrast medium were also compared.Two radiologists performed the double-blind evaluation of the image quality of differ-ent CTA segments in the three groups using a 5-point scale.Kappa analysis was used to analyze the compatibility of two people's scores.Results The radiation dose and contrast medium of group A were reduced by about 68.21%and 44.44%compared with those of group B,respectively.The differences were statistically significant(P<0.05).The SNR,CNR of group A1 were higher than those of group B and group A2,and the differences were statistically significant(P<0.05).The Kappa value of subjective score in group A1 was 0.688;the Kappa value of subjective score in group B was 0.499;the Kappa value of subjective score in group A2 was 0.571,which was in good agreement and statistically significant(P<0.05).Conclusion The"triple-low"technique combined with the AIIR in craniocervical CTA can significantly reduce the radi-ation dose and contrast medium.And its image quality is better than conventional scans which are reconstructed with HIR.

BACKGROUND:In previous studies,the equivalent structure of three-dimensional cell reconstruction of tissue engineering oral mucosa is similar to normal oral mucosa,including epithelial-like structure,lamina propria-like structure,and vascular lumen-like structure,and has initially achieved the establishment of vascular equivalent,but its vascularization characteristics are not very clear.OBJECTIVE:Vascular-like structures of vascularized oral mucosa equivalent were obtained by targeting vascular endothelial cells specific marker expression profiles correlated with laser capture microdissection system,and their vascularization ability was evaluated to reveal their vascularization characteristics.METHODS:Human gingival epithelial cells were cultured from human gingival epithelium and human gingival fibroblasts,human gingival mesenchymal stem cells were cultured from human gingival lamina propria.Human gingival mesenchymal stem cells were induced to differentiate into vascular endothelial-like cells after monoclonal expansion culture.Human gingival epithelial cells,human gingival fibroblasts,and vascular endothelial-like cells were loaded with acellular vascular matrix-0.25%human-like collagen type Ⅰ scaffold to construct the vascularized oral mucosa equivalent.The layered structure of oral mucosa equivalent(experimental group)and the acellular vascular matrix-0.25%human-like collagen type Ⅰ scaffold(control group)were implanted subcutaneously into the back of nude mice,respectively.14 days later,the incision surface of the two groups was coated with biogel.The biogel surface of the experimental group was inoculated with human gingival epithelial cells,while the control group was not inoculated with cells.The samples were collected after 14 days of feeding.The layered structure of oral mucosa equivalent was observed by morphology.The neovascular-like structures in oral mucosa equivalents were labeled by immunohistochemistry and immunofluorescence with a more comprehensive expression profile of vascular endothelial cells,and the vascularization characteristics were analyzed.A laser capture microdissection system was used to capture the neovascularization structures in the oral mucosa equivalents specifically labeled by immunohistochemistry and analyze their vascularization characteristics.RESULTS AND CONCLUSION:(1)The morphology showed that the cell level of oral mucosa equivalent was clear,and the structure was similar to that of normal oral mucosa,that is,there were epithelioid structures,lamina-like structures,and vascular cavelike structures,and there were scattered erythrocytes in the vascular cavelike structures.(2)The results of EdU Apollo tracer seed cells in the oral mucosa equivalent group showed that human gingival epithelial cells labeled with EdU Apollo 488 showed green fluorescence expression.DAPI labeled human gingival fibroblasts showed blue fluorescence expression and formed lamina-like structures in vivo.EdU Apollo 567 labeled vascular endothelial-like cells showed red fluorescence expression and formed a vascular-like structure in vivo.(3)Vascular endothelial cell specific marker expression profile immunofluorescence labeling of vascular structure showed that compared with normal oral mucosa,the expressions of CD31,CD51,CD54,CD105,Tie-2,VWF,vascular endothelial growth factor receptor 1,and vascular endothelial growth factor receptor 2 in oral mucosa equivalents were increased(P<0.000 1).There were no significant changes in CD34 expression(P>0.05).(4)Compared with the specifically labeled oral mucosal vascular structures,the expression levels of CD51,CD54,CD105,Tie-2,VWF,vascular endothelial growth factor receptor 1,and vascular endothelial growth factor receptor 2 of the oral mucosa equivalents targeted by the laser capture microdissection system were increased(P<0.000 1).There were no significant changes in expression of CD31 and CD34(P>0.05).(5)The results showed that the oral mucosa equivalent reconstructed by three-dimensional cell stratification could achieve good vascularization,and its vascularization characteristics were consistent with the immunological function and characteristics of neovascularization.Vascularization helps three-dimensional cell layer reconstruction of oral mucosa equivalent regeneration.

Objective To explore the application value of the"triple-low"(low radiation dose,low contrast medium and low con-trast flow rate)technique combined with the artificial intelligence iterative reconstruction(AIIR)in craniocervical computed tomo-graphy angiography(CTA).Methods Seventy patients undergoing head and neck CTA were prospectively enrolled and randomized into group A and group B,with 35 patients in each group.Group A was the"triple-low"technique group(80 kV,0.4 mL/kg,2.5 mL/s);group B was the control group(120 kV,0.7 mL/kg,5 mL/s).Group A images used AIIR and hybrid iterative reconstruction(HIR),and obtained group A1 and group A2;group B images used HIR.CT values,standard deviation(SD)values,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)at the level of the aortic arch,common carotid artery bifurcation,internal carotid artery segment C3 and middle cerebral artery segment M1 in the three groups of CTA images were measured and analyzed.The radiation dose and contrast medium were also compared.Two radiologists performed the double-blind evaluation of the image quality of differ-ent CTA segments in the three groups using a 5-point scale.Kappa analysis was used to analyze the compatibility of two people's scores.Results The radiation dose and contrast medium of group A were reduced by about 68.21%and 44.44%compared with those of group B,respectively.The differences were statistically significant(P<0.05).The SNR,CNR of group A1 were higher than those of group B and group A2,and the differences were statistically significant(P<0.05).The Kappa value of subjective score in group A1 was 0.688;the Kappa value of subjective score in group B was 0.499;the Kappa value of subjective score in group A2 was 0.571,which was in good agreement and statistically significant(P<0.05).Conclusion The"triple-low"technique combined with the AIIR in craniocervical CTA can significantly reduce the radi-ation dose and contrast medium.And its image quality is better than conventional scans which are reconstructed with HIR.

BACKGROUND:In previous studies,the equivalent structure of three-dimensional cell reconstruction of tissue engineering oral mucosa is similar to normal oral mucosa,including epithelial-like structure,lamina propria-like structure,and vascular lumen-like structure,and has initially achieved the establishment of vascular equivalent,but its vascularization characteristics are not very clear.OBJECTIVE:Vascular-like structures of vascularized oral mucosa equivalent were obtained by targeting vascular endothelial cells specific marker expression profiles correlated with laser capture microdissection system,and their vascularization ability was evaluated to reveal their vascularization characteristics.METHODS:Human gingival epithelial cells were cultured from human gingival epithelium and human gingival fibroblasts,human gingival mesenchymal stem cells were cultured from human gingival lamina propria.Human gingival mesenchymal stem cells were induced to differentiate into vascular endothelial-like cells after monoclonal expansion culture.Human gingival epithelial cells,human gingival fibroblasts,and vascular endothelial-like cells were loaded with acellular vascular matrix-0.25%human-like collagen type Ⅰ scaffold to construct the vascularized oral mucosa equivalent.The layered structure of oral mucosa equivalent(experimental group)and the acellular vascular matrix-0.25%human-like collagen type Ⅰ scaffold(control group)were implanted subcutaneously into the back of nude mice,respectively.14 days later,the incision surface of the two groups was coated with biogel.The biogel surface of the experimental group was inoculated with human gingival epithelial cells,while the control group was not inoculated with cells.The samples were collected after 14 days of feeding.The layered structure of oral mucosa equivalent was observed by morphology.The neovascular-like structures in oral mucosa equivalents were labeled by immunohistochemistry and immunofluorescence with a more comprehensive expression profile of vascular endothelial cells,and the vascularization characteristics were analyzed.A laser capture microdissection system was used to capture the neovascularization structures in the oral mucosa equivalents specifically labeled by immunohistochemistry and analyze their vascularization characteristics.RESULTS AND CONCLUSION:(1)The morphology showed that the cell level of oral mucosa equivalent was clear,and the structure was similar to that of normal oral mucosa,that is,there were epithelioid structures,lamina-like structures,and vascular cavelike structures,and there were scattered erythrocytes in the vascular cavelike structures.(2)The results of EdU Apollo tracer seed cells in the oral mucosa equivalent group showed that human gingival epithelial cells labeled with EdU Apollo 488 showed green fluorescence expression.DAPI labeled human gingival fibroblasts showed blue fluorescence expression and formed lamina-like structures in vivo.EdU Apollo 567 labeled vascular endothelial-like cells showed red fluorescence expression and formed a vascular-like structure in vivo.(3)Vascular endothelial cell specific marker expression profile immunofluorescence labeling of vascular structure showed that compared with normal oral mucosa,the expressions of CD31,CD51,CD54,CD105,Tie-2,VWF,vascular endothelial growth factor receptor 1,and vascular endothelial growth factor receptor 2 in oral mucosa equivalents were increased(P<0.000 1).There were no significant changes in CD34 expression(P>0.05).(4)Compared with the specifically labeled oral mucosal vascular structures,the expression levels of CD51,CD54,CD105,Tie-2,VWF,vascular endothelial growth factor receptor 1,and vascular endothelial growth factor receptor 2 of the oral mucosa equivalents targeted by the laser capture microdissection system were increased(P<0.000 1).There were no significant changes in expression of CD31 and CD34(P>0.05).(5)The results showed that the oral mucosa equivalent reconstructed by three-dimensional cell stratification could achieve good vascularization,and its vascularization characteristics were consistent with the immunological function and characteristics of neovascularization.Vascularization helps three-dimensional cell layer reconstruction of oral mucosa equivalent regeneration.

Objective To investigate the efficacy of video-assisted teaching ward rounds for typical cases of oph-thalmology in clinical practice for medical undergraduates.Methods A total of 45 students from clinical medicine in Peking Union Medical College were enrolled.They were randomly divided into the experimental group(23 students)and control group(22 students).Primary angle closure glaucoma(PACG)was selected as the learning content,the experimental group was trained by video-assisted teaching ward rounds,while the control group was trained by internship in outpatient clinic.All students joined the test of typical case PACG and a ques-tionnaire survey was implemented for the experimental group.Results The average score of experimental group was higher than control group[(84.30±4.53)vs.(78.05±5.76),t＝4.05,P＜0.001].For video-assisted teaching ward rounds,in experimental group,86.9%(20/23)students believed it was more practical,95.6%(22/23)students thought it was very helpful and 91.3%(21/23)students considered it was conductive to im-prove interest of learning and clinical thinking ability.Conclusions Video-assisted teaching ward rounds improves students'understanding memory of ophthalmic typical cases,which is a potential supplement teaching method in clinical practice training of ophthalmology for medical undergraduates.

Currently, the outbreak of the new coronary pneumonia has entered a critical period of screening, prevention and control.In order to block the transmission of the virus in the radiology department, it is particularly important to effectively protect the medical servant while speeding up the flow of inspection.Based on the basis of notification of the bureau of disease control and prevention, the expert consensus of the CMA and CMDA, and the literature review, combined with the previous practical work experience,this article puts forward the recommendations on the important effect of nursing-technology integrated in the imaging examination of novel coronavirus pneumonia, in order to provide reference for the protection of medical servant in the radiology department at the front line of anti-epidemic.