Objective Using the Chinese anthropomorphic chest phantom to measure the absorbed dose of various tissues and organs under different noise index, and to assess the radiation dose of MSCT chest scanning with the effective dose(ED). Methods The equivalence of the Chinese anthropomorphic chest phantom(CDP-1C) and the adult chest on CT sectional anatomy and X-ray attenuation was demonstrated. The absorbed doses of various tissues and organs under different noise index were measured by laying thermoluminescent dosimeters(TLD) inside the phantom, and the corresponding dose-length products(DLP) were recorded. Both of them were later converted into ED and comparison was conducted to analyze the dose levels of chest CT scanning with automatic tube current modulation (ATCM) under different noise index. Student t-test was applied using SPSS 12.0 statistical software. Results The Phantom was similar to the human body on CT sectional anatomy. The average CT value of phantom are -788.04 HU in lung,45.64 HU in heart,65.84 HU in liver,254.32 HU in spine and the deviations are 0.10%,3.04%, 4.49% and 4.36% respectively compared to humans. The difference of average CT value of liver was statistically significant(t=-8.705,P＜0.05),while the differences of average CT values of lung, heart and spine were not significant(t value were -0.752,-1.219,-1.138,respectively and P＞0.05).As the noise index increased from 8.5 to 22.5, the DLP decreased from 393.57 mGy·cm to 78.75 mGy·cm and the organs dose declined. For example, the average absorbed dose decreased from 22.38 mGy to 3.66 mGy in lung. Compared to ED calculating by absorbed dose, the ED calculating by DLP was lower. The ED values of the two methods were 6.69 mSv and 8.77 mSv when the noise index was set at 8.5. Conclusions Application of the Chinese anthropomorphic chest phantom to carry out CT dose assessment is more accurate. The noise index should be set more than 8.5 during the chest CT scanning based on ATCM technique.

ObjectiveTo compare detection rate of pulmonary nodules and the radiation doses of digital tomosynthesis (DTS) and MSCT chest scanning by using the anthropomorphic chest phantom which containsthermoluminescent dosimeters( TLD ) and simulated pulmonary nodules.Methods The radiation doses of DTS and MSCT scanning were measured by using the anthropomorphic chest phantom which contains 45 TLD and simulated pulmonary nodules.The radiation doses of najor organs were converted into effective dose ( ED ). Three radiologists of different clinical experiences independently reviewed and recorded the density,diameter and position of pulmonary nodules.The sensitivity of nodule detection by DTS and MSCT were compared by Fisher exact test and Chi-square test. The paired t test was conducted to analyze the dose levels of DTS and MSCT.ResultsThe sensitivity of detection nodule by DTS and MSCT were 66.7％ (30/45) and 91.1％ (41/45) respectively.Statistically significant difference between the two examinations existed ( x2 =8.073,P ＜ 0.05).The sensitivity of detection - 650 HU ground glass opacity pulmonary nodule by MSCT and DTS were 93.3％ (14/15) and 73.3％ (11/15) respectively.There was no significant difference between DTS and MSCT ( P ＞ 0.05 ).The sensitivity of detection - 800 HU ground glass opacity nodule and ground glass opacity nodule (d ＜ 8 mm) by DTS were 33.3％ (5/15) and 16.7％ (2/12) respectively,which were lower than those by CT[80.0％ (12/15) and 66.7％ (8/12)].The radiation doses of DTS for various organs in the chest were lower than those of CT. Statistical significant difference between DTS and MSCT existed ( lung t =19.69,thoracic vertebral t =30.01,heart t =16.33,liver t =5.06,breast t =9.43,thyroid gland t =8.05 ;P ＜ 0.05).The effective doses of the DTS and MSCT were 0.65 and 7.71 mSv respectively.ConclusionsThere is no difference between the DTS and MSCT in the detection rate of -650 HU ground glass opacity nodule.For detecting the ground glass opacity nodule ( - 800 HU) and ground glass opacity nodule (d ＜ 8 mm),MSCT is superior to DTS. However,the radiation dosage of DTS is 8.41％ of the MSCT scanning.

Objective To analyze the distribution of image noise in low-dose chest CT scan and optimize the relative scanning parameters.Methods The CT images of the Chinese anthropomorphic chest phantom( CDP-1 C) were simulated into six groups of low-dose images with different noise indexs by using an image noise addition tool.The difference between the preset noise index and analog noise value was compared.The CT images of 20 volunteers were also simulated into nine groups of low dose scans with the tube currents of 10,30,50,80,100,120,150,180 and 240 mA.The noise values of images were recorded and analyzed.Results There was no statistical difference between the analog noise value and the noise index.The image noise of low-dose chest scan was increased with the decrease of tube current.The noise was increased quickly when the current was decreased from 50 to 30 mA ( F =24.09 - 40.79,P ＜ 0.05),but the noise increased slowly when the current decreased from 240 to 80 mA.There was no statistical difference between the noise of 80 mA group and that of 120 mA(P ＞ 0.05).Conclusions The noise addition tool can be used to evaluate the image noise of low-dose chest CT scan.Adoption of 80 mA in chest CT scan would result in low radiation dose without adding image noise.

Objective To evaluate the accuracy and efficiency of the Monte Carlo software in measuring the radiation dose to the patients who received the CCTA (Coronary Computed Tomography Angiography) examination.Methods A anthropomorphic chest phantom underwent CCTA using three scan parameters (tube voltage 80 kV,100 kV and 120 kV).Computer Software ImpactDose 2.0 was used to compute the chest organ dose on the basis of the three groups tube voltage CT scan characteristic,and the stimulation results of ImpactDose 2.0 software was verified by use of anthropomorphic phantom thermoluminescence dosimeter experiment method.Results For all the measured organs except for lung,the absorbed organ dose and effective dose of three groups of tube voltages of CCTA measured by the InpactDose 2.0 was lower than those as measured by anthropomorphic phantom study.The relative error of both methods was within ± 50％.Conclusions Monte Carlo software can be used to estimate the levels of radiation dose during CCTA examination with a tolerable error within the acceptable range.

Organ transplantation is the optimal treatment for end-stage organ failure. Nevertheless, organ shortage is a global problem, which limits further development of organ transplantation. Recent research shows that genetically modified pig may become a realistic alternative source of clinical organ transplantation donor. Xenotransplantation may serve as one of the effective measures to resolve the problem of organ shortage. Since 2021, 2 cases of living xenotransplantation and 6 cases of xenotransplantation in brain death recipients have been performed worldwide, and phase Ⅰ clinical trial of xenotransplantation has been launched, and the results have exceeded expectations. Therefore, in this article, recent clinical trial results of xenotransplantation in living and brain death recipients were retrospectively analyzed, and scientific, technical and ethical issues related to clinical research of xenotransplantation were illustrated, hoping to provide reference for clinical research of xenotransplantation in China and promote the development of xenotransplantation in clinical practice.

Objective To explore the public attitude towards kidney xenotransplantation in China by constructing and validating the prediction model based on xenotransplantation questionnaire. Methods A convenient sampling survey was conducted among the public in China with the platform of Wenjuanxing to analyze public acceptance of kidney xenotransplantation and influencing factors. Using random distribution method, all included questionnaires (n=2 280) were divided into the training and validation sets according to a ratio of 7:3. A prediction model was constructed and validated. Results A total of 2 280 questionnaires were included. The public acceptance rate of xenotransplantation was 71.3%. Multivariate analysis showed that gender, marital status, resident area, medical insurance coverage, religious belief, vegetarianism, awareness of kidney xenotransplantation and whether on the waiting list for kidney transplantation were the independent influencing factors for public acceptance of kidney xenotransplantation (all P<0.05). The area under the curve (AUC) of receiver operating characteristic (ROC) of the prediction model in the training set was 0.773, and 0.785 in the validation set. The calibration curves in the training and validation sets indicated that the prediction models yielded good prediction value. Decision curve analysis (DCA) suggested that the prediction efficiency of the model was high. Conclusions In China, public acceptance of kidney xenotransplantation is relatively high, whereas it remains to be significantly enhanced. The prediction model based on questionnaire survey has favorable prediction efficiency, which provides reference for subsequent research.

Objective To analyze the research progress and development trend of xenotransplantation in China. Methods Literatures related to xenotransplantation in Chinese and English were searched from CNKI and Web of Science Core Collection databases from January 1, 2014 to December 31, 2023. Visualization analysis of the research progress, hot topics and research frontiers in this field was performed by CiteSpace software and R language from the aspects of number of publications, keywords, distribution of journal origin, core author cooperation network, main research institutions, and citation of key literatures, etc. Results Chinese scholars published 684 articles in Chinese and 624 articles in English, ranking 2nd worldwide. The top 3 Chinese journals regarding the number of publications were Organ Transplantation, Practical Journal of Organ Transplantation (Electronic Version) and Acta Laboratorium Animalis Scientia Sinica. The top 3 English journals were Xenotransplantation, Frontiers in Immunology and Scientific Reports. The top 5 authors regarding the number of publications in Chinese were Pan Dengke, Cai Zhiming, Mou Lisha, Li Xiao and Dou Kefeng. The top 5 authors regarding the number of publications in English were Mou Lisha, Cai Zhiming, Dai Yifan, Wang Yi and Pan Dengke. High-frequency Chinese keywords included xenotransplantation, immune rejection, transplantation, xenogenic, animal model, xenogeneic bone, liver transplantation, gene editing, kidney transplantation, burn and bone transplantation. High-frequency English keywords were expression, xenotransplantation, cells, transplantation and survival. Conclusions In recent years, certain research achievement and global influence have been obtained in the field of xenotransplantation in China, involving a variety of disciplines and a wide range of research contents. However, cooperation among different institutions is still lacking. In the future, cross-regional and interdisciplinary communication and cooperation should be prompted. Resource sharing and integration should be strengthened to maintain rapid and steady advancement in this field.

Objective To summarize the experience and practical value of living donor kidney harvesting in Bama miniature pigs with six gene modified. Methods The left kidney of Bama miniature pigs with six gene modified was obtained by living donor kidney harvesting technique. First, the ureter was occluded, and then the inferior vena cava and abdominal aorta were freed. During the harvesting process, the ureter, renal vein and renal artery were exposed and freed in sequence. The vascular forceps were used at the abdominal aorta and inferior vena cava, and the renal artery and vein were immediately perfused with 4℃ renal preservation solution, and stored in ice normal saline for subsequent transplantation. Simultaneously, the donor abdominal aorta and inferior vena cava gap were sutured. The operation time, blood loss, warm and cold ischemia time, postoperative complications and the survival of donors and recipients were recorded. Results The left kidney of the genetically modified pig was successfully harvested. Intraoperative bleeding was 5 mL, warm ischemia time was 45 s, and cold ischemia time was 2.5 h. Neither donor nor recipient pig received blood transfusion, and urinary function of the kidney transplanted into the recipient was recovered. The donor survived for more than 8 months after the left kidney was resected. Conclusions Living donor kidney harvesting is safe and reliable in genetically modified pigs. Branch blood vessels could be processed during kidney harvesting, which shortens the process of kidney repair and the time of cold ischemia. Living donor kidney harvesting contributes to subsequent survival of donors and other scientific researches.

Objective To investigate the establishment of a six-gene-edited pig-to-non-human primate kidney xenotransplantation model. Methods The kidney of humanized genetically-edited pig (GTKO/β4GalNT2KO/CMAHKO/hCD55/hCD46/hTBM) was transplanted into a cynomolgus monkey. The survival of the recipient and kidney condition after blood perfusion were observed. The parenchymal echo, blood flow changes, and size of the kidney were monitored on a regular basis. Routine blood test, kidney function test and electrolyte assessment were carried out. Dynamic changes of urine, feces and body mass were monitored. At the end of life, the transplant kidney, heart, liver, spleen, lung, and cecum were collected for pathological examination. Results The recipient died at postoperative 7 d. After blood flow was restored, the kidney was properly perfused, the organ was soft and the color was normal. At the end of the recipient's life, a slight amount of purulent secretion was attached to the ventral side of the kidney, with evident congestion and swelling, showing the appearance of "red kidney". Postoperatively, the echo of renal parenchyma was increased, blood flow was decreased, the cortex was gradually thickened, and a slight amount of effusion surrounded the kidney and abdominal cavity over time. In the recipient, the amount of peripheral red blood cells, hemoglobin, albumin, and platelets was progressively decreased, and serum creatinine level was increased to 308 μmol/L at postoperative 7 d, whereas the K⁺ concentration did not significantly change. Light yellow urine was discharged immediately after surgery, diet and drinking water were resumed within postoperative 3 h, and light yellow and normal-shape stool was discharged. The reddish urine was gradually restored to normal color within postoperative 1 d, which were consistent with the results of the routine urine test. A large amount of brown bloody stool was discharged twice in the morning of 2 d after surgery. Omeprazole was given for acid suppression, and the stool returned to normal at postoperative 4 d. The β₂-microglobulin level was increased to 0.75 mg/L at postoperative 7 d. The body mass was increased by 1.7 kg. Autopsy pathological examination showed interstitial edema and bleeding of the transplant kidney, a large amount of infiltration of lymphocytes and macrophages, infiltration of lymphocytes in the arteriole wall and arterial cavity, accompanied by arteritis changes, lymphocyte infiltration in the cecal stroma and congestion in the spleen tissues. No significant abnormal changes were observed in other organs. Conclusions The humanized genetically-edited pig-to-non-human primate kidney xenotransplantation model is successfully established, and postoperative survival of the recipient is 1 week.

Objective: To investigate the clinicopathological and radiological features of benign fibro-osseous lesion (BFOL). Methods: Sixty-five cases of craniofacial BFOL, eight cases of peripheral ossifying fibroma (POF) and one case of low-grade central osteosarcoma diagnosed at Sichuan Provincial People′s Hospital between January 2010 and March 2019 were collected. The clinicopathologic features, hematoxylin-eosin and immunohistochemical (IHC) staining and radiographic features were analyzed. MDM2 gene amplification was detected by FISH in difficult borderline cases. Results: This cohort of BFOLs included 50 cases of fibrous dysplasia (FD), 12 cases of ossifying fibroma (OF), and three cases of juvenile psammomatoid ossifying fibroma (JPOF). The average ages of patients with FD,OF and JPOF were 31.7, 39.2 and 26.0 years respectively. The male to female ratio was 1.0∶1.8.The average age of POF was 47.0 years, with male to female ratio of 1∶7. Patient of low-grade central osteosarcoma was a 48-year-old man. Twenty-seven cases of FD were located in the jaw, and 23 cases were in other craniofacial bones. Nine cases of OF were located in the jaw, and three cases were in the nasal cavity. Two cases of JPOF were in the nasal sinus, and one was in the jaw. All POF were located in the gingiva, and low-grade central osteosarcoma was located in the mandible. The imaging features of FD were luffa-like or ground-glass like signal shadows with poorly defined borders with expansion. OF had clear borders or sclerosing margins. Both JOF and low-grade central osteosarcoma were expansile intraosseously and with focally invasive nodular masses with ground-glass like signal shadows; and POF showed soft tissue mass with bone formation. Histological features of BFOLs showed mixed fibrous and irregular osteoid lesions. FD had no clear relationship with the host bone and no osteoblasts surrounded the bone trabeculae. Osteoblasts rimming was found in OF, and the boundaries of the host bone were clear. JPOF and low-grade central osteosarcoma infiltrated the host bone focally, and the latter showed mild cellular atypia. MDM2 amplification was detected in low-grade central osteosarcoma. Conclusions BFOLs are a group of fibro-osseous lesions with similar morphology in the head and neck and face, but their clinical features and prognosis are different; and their imaging and histological characteristics are also slightly different. Attentions should be given to the combination of clinical, imaging and pathologic features of BFOLs, especially the differential diagnosis between BFOLs and low-grade central osteosarcoma. Molecular detection could be used to assist the diagnosis in difficult cases.