Objective To evaluate the ambient dose equivalent rates of photons and neutrons inside and outside the door of a 10 MV accelerator room, and to report the shielding effect of boron-containing polyethylene as maze wall lining. Methods The ambient dose equivalent rates of photons and neutrons inside and outside the door of an accelerator room were taken as the research subject. The Kersey, Falcão, and modified Kersey methods were used to calculate the ambient dose equivalent rates of neutrons and neutron capture gamma rays inside and outside the door of the room before and after renovation. Measurements were made using an X-ray/γ-ray dose rate instrument and a neutron ambient dose equivalent rate meter. Calculated and measured results were compared. Results Before renovation, the measured neutron dose rate inside the door was 409 μSv/h, while the calculated values were 323 μSv/h (Kersey method), 428 μSv/h (Falcão method), and 219 μSv/h (modified Kersey method). The Falcão method yielded a value closest to the measured value, while the Kersey and the modified Kersey methods underestimated the value by 21% and 46%, respectively. After the installation of boron-containing polyethylene plates, the measured neutron dose rate inside the door was 190 μSv/h, with a 54% reduction. The neutron and photon ambient dose equivalent rates outside the door were 5.8 μSv/h and 6.0 μSv/h, respectively, before renovation, and 0.14 μSv/h and 1.6 μSv/h, respectively, after renovation. Conclusion For a 10 MV accelerator room, neutron shielding and protection measurements are necessary, especially for rooms with short mazes. The Falcão method provides the best estimate of neutron dose rates inside and outside the door. Using boron-containing polyethylene plates as maze wall lining is an economical and effective shielding method.

Objective To analyze the layout and shielding effectiveness of medical accelerator vaults, and to provide a reference for the layout, shielding design, and optimization of protection of medical accelerator vaults. Methods Four medical accelerator radiotherapy vaults were selected. The layouts of these vaults were compared with the layout requirements in the radiation therapy protection standards. For each vault, the dose rates at four points of interest outside the shielding were calculated, including the primary shielding area, secondary shielding area, maze outer wall, and lateral shielding area. These values were then compared with the actual measurements obtained using a dose rate meter. Results All four vaults were located on the ground floor of the building and included a maze, with the auxiliary rooms all placed outside the treatment rooms. However, one vault was not located at one end of the building, and in another vault, the control room was exposed to direct irradiation of the useful beam. The calculated dose rates outside the primary shielding area ranged from 0.04 μSv/h to 0.62 μSv/h, while the measured values ranged from 0.10 μSv/h to 0.66 μSv/h, with the measured values being higher than the calculated ones. The calculated dose rates outside the secondary shielding area ranged from 0.0005 μSv/h to 0.12 μSv/h, those outside the maze outer wall ranged from 0.06 μSv/h to 0.18 μSv/h, and those outside the lateral shielding area ranged from 0.009 μSv/h to 0.15 μSv/h; the measured values were all below the detection limit. Conclusion Inadequate layouts were observed in some of the accelerator vaults. The calculated and measured dose rates at points of interest outside the vaults were both significantly lower than the shielding protection requirements in standards, indicating that the shielding designs were overly conservative. Construction units should follow the principle of optimization of radiation protection to design the layout and shielding reasonably and pay attention to the underestimation of dose rates outside the primary shielding caused by the tenth value layer.

Objective:To explore the influence of different scanning positions based on chest phantom of computed tomography(CT)scan on chest on image quality and radiation dose.Methods:A thermoluminescent dosimeter(TLD)was placed at the breast area of simulating anthropoid chest phantom.GE Revolution evo CT was used to conduct scan on the conventional supine position(supine group)and prone position(prone group)for chest phantom.Different noise indexes(NI=10-23)were adjusted to control ration doses,and other parameters were fixed,and each group collected 12 sequence images.The average value(AV),standard deviation(SD)of the CT scan at region of interest(ROI)under different scanning positions were recorded to calculate the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the image.The radiation dose at the breast area was measured by TLD,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Results:Under different scanning positions,the radiation dose of breast organs in the prone group was lower than that in the supine group,there was a statistically significant difference between the two groups(t=6.57,P<0.05),while there were not statistically significant differences in CTDIvol and DLP between the two groups(P>0.05).There were not statistically significant differences in the CT values,SD,SNR,CNR of lung tissue,and the CT values of breast tissue between the two groups of images(P>0.05).The SD,SNR and CNR of breast tissue in the prone group were lower than those in the supine group,and the differences were statistically significant(t=-13.33,-10.59,6.70,P<0.05).There were no statistically significant differences in the subjective scores of the clarity of the edge of the tissue within lung,the layers of soft tissue of the breast,noise,and artifacts in the bone tissue between the two groups of images(P>0.05).Conclusion:When low-dose CT physical examination on chest is conducted in clinical practice,the scanning of prone position during undergoing CT scan on chest can obtain image quality that can meet the requirements in diagnosing lung,and reduce the radiation dose on the breast,and conform to the technical principle of optimal radiation protection.

Objective To evaluate the effectiveness of active screening in improving the detection rate of carbape-nem-resistant Enterobacterales(CRE)in the intensive care units(ICUs).Methods From July 2023 to June 2024,active screening of rectal swab CRE was conducted on ICU patients in 10 hospitals.ICU patients who underwent ac-tive screening from July 2023 to June 2024 were selected as the study group,while those who did not undergo active screening from July 2022 to June 2023 were selected as the control group.Difference in CRE detection rates between the two groups of patients was compared.Results A total of 7 803 ICU patients were included in the study group,744 CRE strains were detected,with a detection rate of 9.53％,out of which 304 CRE strains were detected through routine detection(detection rate 3.90％),3 707 patients underwent active screen,440 CRE strains were detected(detection rate 11.87％).7 561 ICU patients were included in the control group,out of which 250 CRE strains were detected through routine detection,with a detection rate of 3.31％.There was a statistically significant difference in the overall detection rate of CRE between two groups of patients(x2=246.18,P＜0.001).In the study group,CRE detection rate of active screening(11.87％)was higher than that of routine detection(3.90％),with statistically significant difference(x2=264.26,P＜0.001).A total of 17 CRE strains were detected from the study group.The proportions of Klebsiella pneumoniae(80.92％vs 73.41％)and Serratia marcescens(2.30％vs0.23％)in the routine detection group were both higher than in the active screening group,while the proportion of Escherichia coli in the routine detection group was lower(8.22％vs 19.55％),all with statistically significant differences(all P＜0.05).Conclusion The prevalence of CRE in ICUs is relatively high,with a wide range of bac-terial species.Active screening can improve the detection rate of CRE.

Objective To conduct bibliometrics and visual analysis of local benign paroxysmal positional verti-go(BPPV)research in the past 20 years for further basic and clinical research in the future.Methods We collected the journal articles on BPPV published between January 1,2004 and December 31,2023 from the databases of CNKI,Wanfang,VIP and Web of Science Core Collection.Multidimensional measurement and visual analysis were carried out using bibliometrics software to identify the research hotspots and new trends in this field,and to deter-mine the cooperation and influence among authors,institutions and journals.Results A total of 717 Chinese papers and 212 SCI papers were utilized for the analysis.The literature in this field gradually increased at an average annual growth rate of 12.8％,among which the Journal of Clinical Otolaryngology Head and Neck Surgery published the most articles(n=167),followed by the Chinese Journal of Otology(n=94)and the Journal of Audiology and Speech Pathology(n=76).The journal with the largest number of SCI publications is Frontiers in Neurology(n=44).In terms of authors and institutions,Zhuang Jianhua published the most Chinese papers,Yang Xu published the most SCI papers,and Shanghai Jiaotong University published the earliest and most SCI papers in this field(n=21).The main research keywords in this realm in recent years involve video head pulse test,vestibular migraine,re-sidual symptoms,residual dizziness and anxiety.The keywords retaining burst intensity to 2023 include video head pulse test,residual dizziness,children,anxiety,and residual symptoms.Conclusion Video head impulse test,re-sidual dizziness,children,anxiety and other aspects are critical areas of ongoing research in BPPV.

Objective To evaluate the effectiveness of active screening in improving the detection rate of carbape-nem-resistant Enterobacterales(CRE)in the intensive care units(ICUs).Methods From July 2023 to June 2024,active screening of rectal swab CRE was conducted on ICU patients in 10 hospitals.ICU patients who underwent ac-tive screening from July 2023 to June 2024 were selected as the study group,while those who did not undergo active screening from July 2022 to June 2023 were selected as the control group.Difference in CRE detection rates between the two groups of patients was compared.Results A total of 7 803 ICU patients were included in the study group,744 CRE strains were detected,with a detection rate of 9.53％,out of which 304 CRE strains were detected through routine detection(detection rate 3.90％),3 707 patients underwent active screen,440 CRE strains were detected(detection rate 11.87％).7 561 ICU patients were included in the control group,out of which 250 CRE strains were detected through routine detection,with a detection rate of 3.31％.There was a statistically significant difference in the overall detection rate of CRE between two groups of patients(x2=246.18,P＜0.001).In the study group,CRE detection rate of active screening(11.87％)was higher than that of routine detection(3.90％),with statistically significant difference(x2=264.26,P＜0.001).A total of 17 CRE strains were detected from the study group.The proportions of Klebsiella pneumoniae(80.92％vs 73.41％)and Serratia marcescens(2.30％vs0.23％)in the routine detection group were both higher than in the active screening group,while the proportion of Escherichia coli in the routine detection group was lower(8.22％vs 19.55％),all with statistically significant differences(all P＜0.05).Conclusion The prevalence of CRE in ICUs is relatively high,with a wide range of bac-terial species.Active screening can improve the detection rate of CRE.

Objective To conduct bibliometrics and visual analysis of local benign paroxysmal positional verti-go(BPPV)research in the past 20 years for further basic and clinical research in the future.Methods We collected the journal articles on BPPV published between January 1,2004 and December 31,2023 from the databases of CNKI,Wanfang,VIP and Web of Science Core Collection.Multidimensional measurement and visual analysis were carried out using bibliometrics software to identify the research hotspots and new trends in this field,and to deter-mine the cooperation and influence among authors,institutions and journals.Results A total of 717 Chinese papers and 212 SCI papers were utilized for the analysis.The literature in this field gradually increased at an average annual growth rate of 12.8％,among which the Journal of Clinical Otolaryngology Head and Neck Surgery published the most articles(n=167),followed by the Chinese Journal of Otology(n=94)and the Journal of Audiology and Speech Pathology(n=76).The journal with the largest number of SCI publications is Frontiers in Neurology(n=44).In terms of authors and institutions,Zhuang Jianhua published the most Chinese papers,Yang Xu published the most SCI papers,and Shanghai Jiaotong University published the earliest and most SCI papers in this field(n=21).The main research keywords in this realm in recent years involve video head pulse test,vestibular migraine,re-sidual symptoms,residual dizziness and anxiety.The keywords retaining burst intensity to 2023 include video head pulse test,residual dizziness,children,anxiety,and residual symptoms.Conclusion Video head impulse test,re-sidual dizziness,children,anxiety and other aspects are critical areas of ongoing research in BPPV.

Objective:To explore the influence of different scanning positions based on chest phantom of computed tomography(CT)scan on chest on image quality and radiation dose.Methods:A thermoluminescent dosimeter(TLD)was placed at the breast area of simulating anthropoid chest phantom.GE Revolution evo CT was used to conduct scan on the conventional supine position(supine group)and prone position(prone group)for chest phantom.Different noise indexes(NI=10-23)were adjusted to control ration doses,and other parameters were fixed,and each group collected 12 sequence images.The average value(AV),standard deviation(SD)of the CT scan at region of interest(ROI)under different scanning positions were recorded to calculate the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the image.The radiation dose at the breast area was measured by TLD,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Results:Under different scanning positions,the radiation dose of breast organs in the prone group was lower than that in the supine group,there was a statistically significant difference between the two groups(t=6.57,P<0.05),while there were not statistically significant differences in CTDIvol and DLP between the two groups(P>0.05).There were not statistically significant differences in the CT values,SD,SNR,CNR of lung tissue,and the CT values of breast tissue between the two groups of images(P>0.05).The SD,SNR and CNR of breast tissue in the prone group were lower than those in the supine group,and the differences were statistically significant(t=-13.33,-10.59,6.70,P<0.05).There were no statistically significant differences in the subjective scores of the clarity of the edge of the tissue within lung,the layers of soft tissue of the breast,noise,and artifacts in the bone tissue between the two groups of images(P>0.05).Conclusion:When low-dose CT physical examination on chest is conducted in clinical practice,the scanning of prone position during undergoing CT scan on chest can obtain image quality that can meet the requirements in diagnosing lung,and reduce the radiation dose on the breast,and conform to the technical principle of optimal radiation protection.

At present, surgical treatment is the most effective method for the treatment of hepatobiliary malignant tumor. However, due to the complex anatomical structure of hepatobiliary region, accompanied by vascular variation, and with the continuous update of medical concepts, the requirements for surgery are more strict. Traditional imaging examination has reached a bottleneck in the support of surgical treatment, while 3D printing technology is compared with the former. It showed strong advantages in preoperative program planning and improving the effect of intraoperative precise resection. At the same time, it also shows great potential for medical assistance and disease treatment in the production of bioactive models, and 3D printing technology has obviously enhanced the understanding of surgery for young doctors, and medical staff can create a variety of highly practical 3D printing models under the existing conditions. In the future, it is expected to overcome the limitations of materials and technology and bring higher therapeutic benefits for the majority of patients.

The global incidence of liver cancer has remained elevated for a long time. As a high-risk country for hepatitis B, China has one of the highest rates of liver cancer in the world. Historically, surgical excision has been the recommended method of treatment for early-stage liver cancer. With the advancement of imaging technology and the growing use of physical treatment in clinics in recent years, microwave ablation has emerged as a new treatment option for patients with small hepatocellular carcinoma and those who have missed the chance for surgery. It is less traumatic, requires less time in the hospital, and is less expensive than the traditional surgery. However, due to several current indication limits and the inability to totally avoid postoperative sequelae, microwave ablation is not appropriate for all patients with liver cancer. This article examines the use, combined therapy, and postoperative consequences of microwave ablation in the treatment of hepatocellular carcinoma, as well as the potential future direction of development in the treatment of hepatocellular carcinoma.