Objective To propose a method for correcting the attenuation of positron emission tomography (PET) data in PET/magnetic resonance (MR) based on transmission scan, and to improve image quality, diagnostic accuracy, and lesion location accuracy. Methods In this study, the head phantom in the national standard GB/T 18988.1—2013 was used as the experimental model. The head phantom contained three 50 mm diameter cylindrical inserts filled with air, water, and solid teflon. The attenuation correction coefficients were calculated and analyzed based on transmission scan. Results With slice = 33 and theta = 0, the attenuation correction coefficient was the largest (about 7.5) when the coincidence line passed through the axis of the phantom. The spatial distribution of the attenuation correction coefficients clearly showed the positions of air insert and teflon insert, indicating that the attenuation correction coefficients calculated from transmission scan data were accurate. In the clinical verification experiment, the attenuation correction method based on transmission scan significantly improved the image quality and showed efficient attenuation correction. Conclusion This paper studied the attenuation correction method for PET data in PET/MR based on transmission scan. This method can improve the image quality. In the future work, the attenuation correction method of PET/MR will be further studied and optimized to facilitate clinical applications.

Objective To propose a method for correcting the attenuation of positron emission tomography (PET) data in PET/magnetic resonance (MR) based on transmission scan, and to improve image quality, diagnostic accuracy, and lesion location accuracy. Methods In this study, the head phantom in the national standard GB/T 18988.1—2013 was used as the experimental model. The head phantom contained three 50 mm diameter cylindrical inserts filled with air, water, and solid teflon. The attenuation correction coefficients were calculated and analyzed based on transmission scan. Results With slice = 33 and theta = 0, the attenuation correction coefficient was the largest (about 7.5) when the coincidence line passed through the axis of the phantom. The spatial distribution of the attenuation correction coefficients clearly showed the positions of air insert and teflon insert, indicating that the attenuation correction coefficients calculated from transmission scan data were accurate. In the clinical verification experiment, the attenuation correction method based on transmission scan significantly improved the image quality and showed efficient attenuation correction. Conclusion This paper studied the attenuation correction method for PET data in PET/MR based on transmission scan. This method can improve the image quality. In the future work, the attenuation correction method of PET/MR will be further studied and optimized to facilitate clinical applications.

Objective To identify early Klebsiella pneumoniae(KP)infection after liver transplantation and its impact on prognosis.Methods Clinical data of 171 liver transplant recipients were retrospectively analyzed,and they were divided into the non-infection(n=52)and infection groups(n=119)according to the bacterial culture results at postoperative 2 weeks.In the infection group,KP was not detected in 86 cases(non-KP infection group),and KP was cultured in 33 cases(KP infection group).Preoperative,intraoperative and postoperative data were statistically compared between the non-infection and infection groups,and between the non-KP infection and KP infection groups.The risk factors of early KP infection after liver transplantation and the influencing factors of long-term survival of the recipients were analyzed.Results Compared with the non-infection group,model for end-stage liver disease(MELD)score and total bilirubin level were higher,the operation time was longer,the length of postoperative intensive care unit(ICU)stay and the length of hospital stay were longer,the amount of intraoperative red blood cell transfusion was higher,the hospitalization expense was higher,the incidence of severe complications was higher,white blood cell count,absolute neutrophil cell count and neutrophil-to-lymphocyte ratio at postoperative 14 and 30 d were higher,absolute lymphocyte count at postoperative 14 d was lower and hemoglobin level at postoperative 30 d was lower in the infection group.The differences were statistically significant(all P＜0.05).Compared with the non-KP infection group,MELD score,total bilirubin level and aspartate aminotransferase(AST)level were higher,the operation time and the length of postoperative ICU stay were longer,the hospitalization expense was higher,the 90-d fatality was higher,the albumin level at postoperative 14 d was lower,and total bilirubin level at postoperative 30 d was higher in the KP infection group.The differences were statistically significant(all P＜0.05).Among 33 recipients with KP infection,16 cases were resistant to carbapenem antibiotics,and 7 of them died within postoperative 90 d.Seventeen cases were intermediate or sensitive to carbapenem antibiotics,and 4 of them died within postoperative 90 d.Preoperative MELD score ≥17 and operation time≥415 min were the independent risk factors for KP infection after liver transplantation(both P＜0.05).The length of postoperative ICU stay ≥44 h and KP infection were the independent risk factors for long-term prognosis of liver transplantation(both P＜0.05).Conclusions KP infection is an independent risk factor for death after liver transplantation.High preoperative MELD score and long operation time are the independent risk factors for early KP infection after liver transplantation.

Objective To compare the discrepancies among results of three commonly used laboratory direct test methods for maximal oxygen uptake(VO2max),explore their linear regression relationships,mutual predictability and comparability.Methods Using a quasi-experimental design of cluster sampling and within-group interaction design,20 male cross-country skiers were tested for VO2max using the Bruce protocol(Method 1),90-second incremental load exercise on power bicycle(Method 2),and 1-minute incremental load exercise on treadmill(Method 3),with an interval of one week.The indepen-dent and dependent variable were the three VO2max test methods and the VO2max,respectively.Results Significant differences were found in the average VO2max of the three test results,with the value mea-sured by Method 1 ranking the first,followed by that assessed by Method 3 and Method 2(P<0.05).Moreover,the frequency of individual differences in the results of the three methods showed that the VO2max of Method 1 was about 6 and 3 ml/min·kg higher than that measured by Method 2 and 3.However,at the same treadmill speed,the average blood lactate evaluated using Method 3 was higher than Method 1,and the speed reached aerobic and anaerobic thresholds about one speed unit(1 km/h)lower than Method 1.Meanwhile,linear regression analyses of the test results between Method 1 and 2,as well as Method 1 and 3 showed that both the regression models and coefficients were statis-tically significant(P<0.001),with the R-squared values of 9.25 and 9.05,respectively.Conclusion The Bruce protocol performs best in assessing the maximum value of the athlete's VO2max phase,whose results have linear regression relationships with the other two methods,and can be used for pre-dicting their results.Moreover,athletes of different events and levels can choose different VO2max test methods accordingly.Lastly,the speed and heart rate ranges corresponding to the aerobic and anaero-bic thresholds can serve as an effective and convenient method to control the training intensity.

Objective To investigate the correlation between the expression of serum 25hydroxyvitamin D[25(OH)D]and growth differentiation factor 15(GDF-15)levels and the risk of malignancy in patients with metabolic syndrome(MS)and the development of combined thyroid nodules(TN).Methods From August 2019 to August 2023,185 MS patients who visited the First Affiliated Hospital of Xinjiang Medical University were regarded as the study subjects,according to the results of thyroid ultrasound examination,they were separated into MS group(n=73)and MS+TN group(n=112).According to the malignant grading of thyroid nodules,MS+TN patients were separated into benign group(n=89)and malignant group(n=23).Another 68 healthy individuals who underwent physical examinations were regarded as control group.Enzyme-linked immunosorbent assay(ELISA)was applied to determine the levels of serum 25(OH)D and GDF-15 in each group.Pearson was applied to analyze the correlation between serum 25(OH)D and GDF-15 levels and clinical indicators in MS in TN patients.Multivariate Logistic regression was applied to analyze the influencing factors of malignant TN in patients with MS combined with TN.Receiver operating characteristic(ROC)curve was plotted to evaluate the diagnostic value of serum 25(OH)D and GDF-15 levels in MS with malignant TN.Results Comparison of serum 25(OH)D(30.41±6.73 ng/ml,27.23±6.15 ng/ml,24.67±4.38 ng/ml)and GDF-15(167.99±22.56 ng/L,239.75±25.92 ng/L,286.63±26.04 ng/L)levels in control,MS and MS+TN groups,the differences were statistically significant(F=22.219,472.113,all P<0.05).Compared with the benign group,the serum 25(OH)D(26.28±4.53 ng/ml vs 18.44±3.79 ng/ml)level in the malignant group was obviously reduced,while the GDF-15(276.93±24.53 ng/L vs 324.17±31.89 ng/L)level was obviously increased,the differences were statistically significant(t=7.631,7.718,all P＜0.05).The BMI,age,FPG,TG,TSH and TGAb levels of patients in the malignant group were obviously higher than those in the benign group,the difference were statistically significant(t=2.868,3.523,3.542,3.603,4.581,5.516,all P＜0.05).Pearson correlation analysis,and the serum 25(OH)D level in MS patients with TN was negatively correlated with FPG,TSH,TG and TGAb levels(r=-0.302,-0.482,-0.524,-0.546,all P<0.001),while GDF-15 level was positively correlated with TG,TSH,TGAb and FPG levels(r=0.467,0.541,0.578,0.623,all P<0.05).Multivariate logistic regression analysis,GDF-15(OR=1.673,95%CI:1.146～2.442)was a risk factor for the occurrence of malignant TN in MS patients(P<0.05),and 25(OH)D(OR=0.744,95%CI:0.604～0.916)was a protective factor for the occurrence of malignant TN,the AUC values of serum 25(OH)D and GDF-15 levels in the diagnosis of MS combined with malignant TN were 0.813,0.799 and 0.930,respectively,and the combination was superior to the single diagnosis(Z=2.088,2.021,P=0.037,0.043).Conclusion The levels of serum 25(OH)D and GDF-15 in patients with MS combined with TN are obviously correlated with nodular nature.The decrease in serum 25(OH)D level and the increase in GDF-15 level are risk factors for malignant TN in MS patients.

Objective:To investigate the clinical characteristics and management status of children with Turner syndrome (TS) in China.Methods:As a cross-sectional study, 1 089 TS patients were included in the database of the National Collaborative Alliance for the Diagnosis and Treatment of Turner Syndrome from August 2019 to November 2023. Clinical characteristics (growth development, sexual development, organ anomalies, etc.), karyotypes, auxiliary examinations, and treatments were collected and analyzed.Results:Among the 1 089 TS cases, 809 were recorded karyotypes. The karyotype distribution was as follows: 45, X in 317 cases (39.2%), X chromosome structural variants (including partial deletions of p or q arm, ring chromosome, and marker chromosome) in 89 cases (11.0%), 45, X/46, XX mosaicism in 158 cases (19.5%), mosaicism with X chromosome structural variants in 209 cases (25.8%), and presence of Y chromosome material in 36 cases (4.4%). Among the 824 TS cases, the age of diagnosis was 9.7(6.4, 12.2) years, with a height standard deviation score (HtSDS) of -3.1±1.2. Five hundred and fifty three cases underwent growth hormone (GH) stimulation test, and 352 cases (63.7%) had GH peak values <10 μg/L and 75.9% (577/760) had low IGF1 levels, with IGF1 SDS ≤-2 accounting for 38.2% (290 cases). Among 471 cases aged ≥8 years, 132 cases (28.0%) showed spontaneous sexual development (mean bone age (11.0±1.7) years), 10 cases had spontaneous menarche (mean bone age (12.0±2.2) years), and 2 cases had regular menstrual cycles. Common physical features included cubitus valgus (311 cases (28.5%)), neck webbing (188 cases (17.2%)), low posterior hairline (185 cases (17.0%)), shield chest (153 cases (14.0%)), high arched palate (127 cases (11.6%)), short fourth metacarpal (43 cases (3.9%)), and spinal abnormalities (38 cases (3.5%)). Congenital cardiovascular and urogenital anomalies occurred in 91 cases (19.4%) and 66 cases (12.0%)respectively. Abdominal ultrasound in 33 cases (7.2%) indicated fatty liver, hepatomegaly, intrahepatic bile duct stones, and splenomegaly. Among 23 cases undergoing oral glucose tolerance test (OGTT) test, 2 were diagnosed with diabetes mellitus and 4 with impaired glucose tolerance. Following diagnosis, 669 cases (80.7%) received rhGH treatment at a chronological age of (9±4) years and bone age of (8.3±3.2) years. Additionally, 112 cases (19.4%) received sex hormone replacement therapy starting at the age of (14±4) years and bone age of (12.6±1.2) years.Conclusions:The karyotypes of 45, X and mosaicism were most common in Chinese children with TS. The clinical manifestations were mainly short stature and gonadal dysplasia. However, a few TS children could be in the normal range of height, and some cases among those aged of ≥8 years old had spontaneous sexual development. Some exhibited physical features, congenital cardiovascular and urogenital anomalies, and dysfunction of the hypothalamic-pituitary-IGF1 axis. Moreover, a few of them developed impaired glucose tolerance and diabetes mellitus. Following diagnosis, most of the patients received rhGH treatment, and a few of them received sex hormone replacement therapy.

Objective To analyze the clinical efficacy of transcatheter tricuspid valve replacement (TTVR) in cardiac implantable electronic lead-related tricuspid regurgitation (TR). Methods The patients with severe TR who underwent LuX-Valve TTVR in 9 Chinese medical centers from June 2020 to August 2021 were retrospectively enrolled. They were divided into a cardiac implantable electronic device (CIED) group and a non-CIED group based on whether they had pre-existing CIED implantation. Success of the procedure was defined as safe implantation of the LuX-Valve and complete withdrawal of the delivery system. Prognostic improvement was defined as a decrease of TR grade to≤2+ and an improvement of cardiac function by≥2 grades. Surgical success and postoperative prognosis were compared between the two groups. Results A total of 190 patients were collected, including 50 males and 140 females with a mean age of 66.2±7.8 years. There were 29 patients in the CIED group, and 161 patients in the non-CIED group. In the CIED group, 28 patients were implanted with a permanent pacemaker and 1 patient with a cardioverter-defibrillator. Preoperative New York Heart Association (NYHA) cardiac function class, TR degree, left ventricular ejection fraction, tricuspid annular plane systolic excusion, and cardiac risk scores were comparable between the two groups (P>0.05). Postoperative TR was reduced to≤2+ in all patients, and there was no statistical difference in the incidence of perivalvular leakage between the two groups (P=0.270). Postoperative CT of CIED patients showed the valve was in place, and the lead was not extruded, twisted, or deflected. The in-hospital mortality of the two groups were 10.3% and 1.9%, respectively, and the difference was statistically significant (P=0.047). In addition, there was no statistical difference between the two groups in terms of postoperative improvement of cardiac function and mortality in the 1- and 2-year follow-up. Conclusion TTVR is feasible, safe, and effective in patients with CIED implantation, and the pre-existing lead has no significant effect on the clinical efficacy.

Objective To investigate the effect of 100 kVp low tube voltage combined with adaptive statistical iterative reconstruc-tion-Veo(ASIR-V)on the imaging display,image quality and radiation dose of Adamkiewicz artery(AKA).Methods Ninety patients with computed tomography angiography(CTA)of aorta were randomly divided into two groups.In group A,the tube voltage was 100 kVp,and ASIR-V was 80%reconstructed.The tube voltage in group B was 120 kVp,and adaptive statistical iterative recon-struction(ASIR)was 40%reconstructed.The CT value and the standard deviation(SD)value of descending aorta were measured at the 12th thoracic vertebra level,and the CT value and the SD value of the spinal cord were measured at the same level to calculate the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of AKA.According to the continuity between AKA and intercostal artery or lumbar artery,the visualization of AKA was evaluated by two doctors with a double-blinded method and a five-point method,and the radiation doses of group A and group B were compared.Results Compared with group B,the CT value of aorta in group A was sig-nificantly increased by about 22.83%(P<0.001).The background noise of AKA in group A was significantly lower than that in group B(P<0.001),and the SNR and CNR were significantly higher than those in group B(P<0.001).The visualization score of AKA in group A was higher than that in group B(P<0.05).The effective dose(ED)in group A was significantly lower than that in group B by about 41.28%(P<0.001).Conclusion 100 kVp combined with ASIR-V technique for spinal cord AKA imaging can obtain better image quality,improve the sensitivity of AKA display and reduce the radiation dose.

Objective:To document any correlation between eye-tracking test results and cognitive impairment after a stroke.Methods:Forty stroke survivors made up the stroke group, while 20 healthy subjects without a history of stroke formed the normal group. Everyone was given an eye-tracking test, the mini-mental state examination (MMSE), and the Montreal Cognitive Assessment (MoCA). The eye-tracking test results were then tested for any correlation with age, level of education, and the MMSE and MoCA scores.Results:In the static image test and the prosaccade test, the total number of fixations was significantly higher in the stroke group than in the normal group. In the dynamic path test, the ocular motor test and the anti-saccade test, significant differences were observed between the two groups in terms of the duration of total fixation, the fixation duration ratio, and the total number of fixations. In the static image test, the total number of fixations was weakly negatively correlated with the MMSE scores. Total fixation duration and fixation duration ratio were weakly positively correlated with the MoCA scores, while total number of fixations, total saccade distance and average saccade velocity were weakly negatively correlated with the MoCA scores. In the dynamic path test, total fixation duration was weakly positively correlated with the MMSE and MoCA scores. Fixation duration ratio was weakly positively correlated with the MMSE scores and weakly negatively correlated with the MoCA scores. First fixation duration was weakly positively correlated with the MoCA scores. The total number of fixations was weakly positively correlated with age and weakly negatively correlated with the MoCA scores. Total saccade distance was weakly negatively correlated with age and the MoCA scores, and average saccade velocity was weakly negatively correlated with the MMSE and MoCA scores. In the ocular motor test, total fixation duration and fixation duration ratio were weakly positively correlated with the MoCA scores. Total number of fixations, total saccade distance, and average saccade velocity were weakly negatively correlated with the MoCA scores. In the prosaccade test, total fixation duration and fixation duration ratio were weakly positively correlated with the MoCA scores. Total number of fixations was weakly positively correlated with age and weakly negatively correlated with the MoCA scores. Total saccade distance and average saccade velocity were weakly negatively correlated with both the MMSE and MoCA scores. In the anti-saccade test, total fixation duration was weakly and positively correlated with age and the MoCA scores. Fixation duration ratio was weakly and positively correlated with age and the MoCA scores. The total number of fixations was weakly positively correlated with age and weakly negatively correlated with the MoCA scores, and total saccade distance and average saccade velocity were weakly negatively correlated with the MoCA scores.Conclusions:Eye-tracking test results are significantly correlated with post-stroke cognitive impairment, suggesting that such tests can be used in the assessment of post-stroke cognitive dysfunction.

Objective To investigate the value of serum soluble CD40 ligand(sCD40L)for gestational diabetes mellitus(GDM)and adverse pregnancy outcomes.Methods A total of 100 pregnant women with GDM who received regular prenatal check-up and delivered in Zhongshan Torch Development Zone People's Hospital from January to December 2023 were included in GDM group,and 50 pregnant women with normal blood glucose levels who received regular prenatal check-up and delivered in the hospital during the same period were included in normal control group.Clinical data of two groups were collected and pregnancy outcomes were followed up.Receiver operating characteristic(ROC)curve was used to evaluate the diagnostic value of sCD40L in GDM,and multifactor Logistic regression model was used to explore the risk factors of GDM.Results Serum sCD40L levels in GDM group were significantly higher than those in normal control group at different time points during pregnancy(P＜0.05).ROC curve showed that the best cutoff values of serum sCD40L level in the first and second trimesters in assisting the diagnosis of GDM were 0.975ng/ml and 1.195ng/ml,the area under the curve was 0.812 and 0.878,and the sensitivity was 73.08％and 78.43％,the specificity was 78.05％and 80.00％,respectively.Multivariate Logistic regression showed that age 30-39 years old,family history of diabetes mellitus,higher fasting blood glucose in first trimester,higher sCD40L in first trimester and second trimester were all independent risk factors for GDM(P＜0.05).The levels of serum sCD40L in the first,second and third trimesters of GDM women with adverse pregnancy outcome were significantly higher than those in GDM women with normal pregnancy outcome(P＜0.05).Conclusion Serum sCD40L levels are abnormally increased in pregnant women with GDM and adverse pregnancy outcomes,and serum sCD40L levels in first and second trimesters may have early warning value for GDM.