Objective:To establish reference ranges for left and right ventricular structure and function parameters using cardiovascular magnetic resonance (CMR) in healthy Tibetan natives residing at ultra-high altitudes, and analyze their influencing factors.Methods:This prospective study enrolled Tibetan healthy volunteers who underwent CMR examinations between September 2021 and August 2022. Participants were stratified into four age groups: 20-29, 30-39, 40-49, and 50-59 years. CMR-derived parameters included left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), left/right ventricular end-diastolic volumes (LVEDV/RVEDV), left/right ventricular end-systolic volumes (LVESV/RVESV), and end-diastolic left ventricular mass (LVM at ED). Normally distributed data were compared between genders using independent samples t-test and among age groups using ANOVA. Non-normally distributed data were analyzed with Kruskal-Wallis test. Linear regression assessed relationships between parameters and gender, age, residential altitude, body surface area (BSA), and body mass index (BMI). Results:The study included 66 volunteers (27 males, 39 females), distributed as follows: 21 (20-29 years), 15 (30-39 years), 15 (40-49 years), and 15 (50-59 years). Reference values were: LVEF (62.6±5.7)%, RVEF (55.0±7.1)%, BSA-indexed LVEDV (60.6±12.1)ml/m2, RVEDV (65.5±14.8)ml/m2, LVESV (22.7±5.9)ml/m2, RVESV (29.6±8.1)ml/m2, and LVM at ED (39.1±8.0)g/m2. Gender and age significantly affected RVEF, RVESV, and LVM at ED ( P<0.05). Multivariate regression revealed:Gender independently predicted RVEF ( β=-5.556, P=0.003), RVESV ( β=5.421, P=0.007), and LVM at ED ( β=8.338, P<0.001). Age negatively influenced RVESV ( β=-0.202, P=0.019). BSA positively correlated with LVM at ED ( β=19.980, P=0.041). No significant associations were found with residential altitude or BMI ( P>0.05). Conclusion:This study establishes preliminary reference ranges for ventricular parameters in Tibetan ultra-high altitude natives, with gender, age, and BSA identified as key determinants of cardiac structural/functional indices.

Objective To validate the diagnostic performance and risk stratification ability of an AI-based recognition system(PE-AI)for pulmonary embolism(PE)using computed tomography pulmonary angiography(CTPA)so as to analyze its diagnostic value in clinical practice.Methods A total of 416 patients with suspected PE who underwent CTPA from January 1,2023 to December 10,2023 at our hospital were included in this study.Two junior radiologists and PE-AI separately detected and diagnosed emboli in the collected cases by double-blind method,and recorded the diagnosis time respectively.Three senior radiologists reviewing with clinical follow-up results were used as the gold standard in this study.Diagnostic performance was evaluated by using the receiver operating characteristic(ROC)curve analysis and Delong-t test.For positive cases,the pulmonary artery obstruction index(PAOI)calculated by AI and manually were collected respectively and consistency analysis was performed.Results The area under the curve(AUC)of PE-AI,manual and combined diagnosis was 85.6％,90.8％and 95.1％,respectively,which differed significantly(P＜0.05).The reading time of PE-AI[(0.16±0.07)min]was significantly lower than the time of manual[(4.42±1.85)min,P＜0.001]and combined diagnosis[(4.58±1.84)min,P＜0.001].The PAOI measured by PE-AI and manually had high consistency(intraclass correlation efficient,ICC=0.80)in the subgroup analysis of confirmed cases.Conclusion AI can quickly identify pulmonary artery emboli in a short time and assist radiologists to improve diagnostic efficiency.At the same time,through the intelligent detection of PAOI,it is helpful for the risk stratification of patients with PE and optimizing the diagnosis and treatment pathway for pulmonary embolism.

The medical mask,which is used as an important tool of preventing the spread of respiratory diseases,can effectively block the transmission of biological aerosols.The detection for the filtration efficiency of bacteria in medical mask is particular importance.The Andersen sampler,is one kind of device that samples microbial aerosols,is widely used in the inspection for the filtration efficiency for bacteria in medical masks.It mainly consists of six impactors with different pore sizes.It simulates the deposition process of the most of particles at different positions in respiratory system through the bacterial particles in biological aerosols impact respectively the surface of petri dishes with agar under different pore sizes.This paper explored the development background,structure and sampling principle,operation and counting procedures of the Andersen sampler,as well as its application and importance in the inspection for the filtration efficiency for bacteria in medical mask.

Video-assisted thoracoscopic surgery (VATS) is the standard procedure for the treatment of lung cancer in the early and middle stages in recent years. The diaphragm is the main respiratory muscle that maintains effective pulmonary ventilation. Diaphragmatic dysfunction is a short-term or permanent dysfunction of one or both diaphragms caused by various factors, mainly manifested as diaphragm distension, diaphragm weakness and diaphragm paralysis, which can lead to respiratory dysfunction, even respiratory failure. This article reviews the etiology, clinical symptoms and signs, diagnosis, treatment and prognosis of diaphragmatic dysfunction after VATS lobectomy, aiming to provide clinicians with assessment methods and management framework for timely diagnosis and treatment of diaphragmatic dysfunction after VATS lobectomy, so as to optimize postoperative respiratory rehabilitation and improve long-term prognosis and quality of life of patients.

Objective To validate the diagnostic performance and risk stratification ability of an AI-based recognition system(PE-AI)for pulmonary embolism(PE)using computed tomography pulmonary angiography(CTPA)so as to analyze its diagnostic value in clinical practice.Methods A total of 416 patients with suspected PE who underwent CTPA from January 1,2023 to December 10,2023 at our hospital were included in this study.Two junior radiologists and PE-AI separately detected and diagnosed emboli in the collected cases by double-blind method,and recorded the diagnosis time respectively.Three senior radiologists reviewing with clinical follow-up results were used as the gold standard in this study.Diagnostic performance was evaluated by using the receiver operating characteristic(ROC)curve analysis and Delong-t test.For positive cases,the pulmonary artery obstruction index(PAOI)calculated by AI and manually were collected respectively and consistency analysis was performed.Results The area under the curve(AUC)of PE-AI,manual and combined diagnosis was 85.6％,90.8％and 95.1％,respectively,which differed significantly(P＜0.05).The reading time of PE-AI[(0.16±0.07)min]was significantly lower than the time of manual[(4.42±1.85)min,P＜0.001]and combined diagnosis[(4.58±1.84)min,P＜0.001].The PAOI measured by PE-AI and manually had high consistency(intraclass correlation efficient,ICC=0.80)in the subgroup analysis of confirmed cases.Conclusion AI can quickly identify pulmonary artery emboli in a short time and assist radiologists to improve diagnostic efficiency.At the same time,through the intelligent detection of PAOI,it is helpful for the risk stratification of patients with PE and optimizing the diagnosis and treatment pathway for pulmonary embolism.

The medical mask,which is used as an important tool of preventing the spread of respiratory diseases,can effectively block the transmission of biological aerosols.The detection for the filtration efficiency of bacteria in medical mask is particular importance.The Andersen sampler,is one kind of device that samples microbial aerosols,is widely used in the inspection for the filtration efficiency for bacteria in medical masks.It mainly consists of six impactors with different pore sizes.It simulates the deposition process of the most of particles at different positions in respiratory system through the bacterial particles in biological aerosols impact respectively the surface of petri dishes with agar under different pore sizes.This paper explored the development background,structure and sampling principle,operation and counting procedures of the Andersen sampler,as well as its application and importance in the inspection for the filtration efficiency for bacteria in medical mask.

Objective:To establish reference ranges for left and right ventricular structure and function parameters using cardiovascular magnetic resonance (CMR) in healthy Tibetan natives residing at ultra-high altitudes, and analyze their influencing factors.Methods:This prospective study enrolled Tibetan healthy volunteers who underwent CMR examinations between September 2021 and August 2022. Participants were stratified into four age groups: 20-29, 30-39, 40-49, and 50-59 years. CMR-derived parameters included left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), left/right ventricular end-diastolic volumes (LVEDV/RVEDV), left/right ventricular end-systolic volumes (LVESV/RVESV), and end-diastolic left ventricular mass (LVM at ED). Normally distributed data were compared between genders using independent samples t-test and among age groups using ANOVA. Non-normally distributed data were analyzed with Kruskal-Wallis test. Linear regression assessed relationships between parameters and gender, age, residential altitude, body surface area (BSA), and body mass index (BMI). Results:The study included 66 volunteers (27 males, 39 females), distributed as follows: 21 (20-29 years), 15 (30-39 years), 15 (40-49 years), and 15 (50-59 years). Reference values were: LVEF (62.6±5.7)%, RVEF (55.0±7.1)%, BSA-indexed LVEDV (60.6±12.1)ml/m2, RVEDV (65.5±14.8)ml/m2, LVESV (22.7±5.9)ml/m2, RVESV (29.6±8.1)ml/m2, and LVM at ED (39.1±8.0)g/m2. Gender and age significantly affected RVEF, RVESV, and LVM at ED ( P<0.05). Multivariate regression revealed:Gender independently predicted RVEF ( β=-5.556, P=0.003), RVESV ( β=5.421, P=0.007), and LVM at ED ( β=8.338, P<0.001). Age negatively influenced RVESV ( β=-0.202, P=0.019). BSA positively correlated with LVM at ED ( β=19.980, P=0.041). No significant associations were found with residential altitude or BMI ( P>0.05). Conclusion:This study establishes preliminary reference ranges for ventricular parameters in Tibetan ultra-high altitude natives, with gender, age, and BSA identified as key determinants of cardiac structural/functional indices.

Objective To evaluate the application value of the three-point localization method in improving the quality and efficiency of four-chamber view acquisition in cardiac magnetic resonance(CMR)imaging.Methods A total of 215 patients who underwent four-chamber view in CMR imaging from January 2022 to October 2023 were retrospectively enrolled and divided into two groups.The control group(n=109)received traditional localization method while the study group(n=106)received three-point localization method.The image quality of mitral valve,tricuspid valve and cruciform structure in four-chamber view images were assessed by two radiologists using a Likert 4-piont scale.The time-consumption from scout imaging to the finish of four-chamber view imaging was recorded.Constituent data and numeral data were compared by Chi-square test and two-sample t test,respectively.Kappa test was used to analyze the inter-observer consistency.Results There were no significant inter-group differences in gender,age,disease profile,or the radiographers'experience.The mean quality scores of the mitral valve,tricuspid valve and cruciform structure in the control group and the study group were 3.44±0.64 and 3.63±0.49(P=0.023),3.43±0.67 and 3.53±0.60(P=0.202),3.71±0.49 and 3.83±0.35(P=0.047),respectively.The image quality score was higher in the study group than in the control group,with the differences in mitral valve and cruciform structure reaching statistical significance.The time-consumption for obtaining four-chamber view for the control group and the study group was 11.67±3.49 minutes and 7.212±1.83 minutes,respectively,with statistically significant differences(P＜0.001).Conclusion Compared with the traditional localization method,the three-point localization method provides better image quality in four-chamber view imaging with shortened imaging time.

Objective To evaluate the relationship between the pericoronary fat attenuation index(FAI)and the image reconstruction parameters of computed tomography(CT)coronary angiography,including reconstruction kernel,iterative reconstruction algorithm and image thickness.Methods Forty-four CT coronary angiography scans were prospectively enrolled.All scans were reconstructed by three means as follows:① Four different kernels(Soft_AA,Soft_BA,Soft_CA,and Soft_DA,sharpness from low to high)as the iterative reconstruction algorithm(KARL5)and image thickness(0.5 mm)remained unchanged.② Filtered back projection(FBP)and iterative reconstruction kernel(KARL5)as the kernel and image thickness(0.5 mm)remained unchanged.③ Different image thickness(0.5 mm and 1 mm)as the kernel(Soft_AA)and iterative reconstruction algorithm(KARL5)remained unchanged.The FAI of left anterior descending artery(LAD),left circumflex artery(LCX),and right coronary artery(RCA)was calculated using a dedicated software.Paired t-test and analysis of variance were used for statistical analysis.Results For LAD,LCX and RCA:① The differences of FAI among different reconstruction kernels reached statistical significance(P＜0.001),and FAI decreased as the sharper kernel was used.③ Compared with FBP,the FAI of KARL5-reconstructed images significantly increased(P＜0.001).③ Compared with 0.5 mm,the FAI of images with 1.0 mm thickness significantly decreased(P＜0.001).Conclusion The kernel,iterative reconstruction algorithms,and image thickness all have a significant impact on the FAI of each coronary artery.When using FAI for clinical diagnosis,the effect of CT reconstruction parameters should be taken into account.

Objective To investigate the value of combined serum levels of neutrophil gelatinase-associated lipocalin(NGAL)and growth differentiation factor 15(GDF-15)in diagnosis of renal injury in elderly patients with H-type hypertension.Methods A total of 177 patients with H-type hypertension admitted to Department of Neurology and Department of General Medicine of the Affiliated Hospital of Chengde Medical College from April 2021 to June 2022 were enrolled,and based on their estimated glomerular filtration rate(eGFR),they were divided into the renal im-pairment group(81 cases)and normal renal function group(96 cases).General data and laboratory indicators were collected in the two groups.ROC curve analysis was used to evaluate the diagnos-tic value of combined NGAL and GDF-15 levels for renal injury in the elderly patients with H-type hypertension,and Pearson correlation analysis was performed to analyze the correlation between serum NGAL and GDF-15 levels and renal injury in the patients.Results SBP level was significantly higher in the renal impairment group than the normal renal function group[148.53±14.62 mm Hg(1 mm Hg=0.133 kPa)vs 138.75±13.36 mm Hg,P＜0.01],but no such difference was observed in DBP level between the two groups(P＞0.05).The levels of creatinine(Cr),urea nitrogen(BUN),β2-microglobulin(β2-MG),cystatin C(Cys C),urinary microalbumin(MA),NGAL and GDF-15 levels were obviously higher in the renal impairment group than the group with normal renal function(P＜0.01).ROC curve analysis showed that the combined detection of NGAL and GDF-15 levels was significantly higher than that of the two indicators alone(P＜0.01).Pearson correlation analysis indicated that serum NGAL and GDF-15 levels were positively correlated with Cr,BUN,β2-MG,Cys C and MA levels(P＜0.01).Conclusion Serum NGAL and GDF-15 levels are elevated in elderly H-type hypertension patients.Combined detection of the two indicators has higher value in the diagnosis of renal injury in elderly H-type hypertension patients.