Background and purpose:In the quality control of mammography,the signal-to-noise ratio(SNR)refers to the ratio of the useful signal intensity to the background noise in the image,which is one of the important indicators for measuring the quality of the image.The coefficient of variation(CoV)is a commonly used indicator to describe the consistency and repeatability of SNR.This study aimed to assess the stability and repeatability of mammographic device performance by analyzing the changes in SNR CoV in two-dimensional(2D)images and tomosynthesis images(referred to as Tomo images)under different exposure modes using three mammographic devices from different manufacturers.Methods:A polymethylmethacrylate(PMMA)phantom designed for mammography quality control was used to perform automatic exposure detection at PMMA thicknesses ranging from 20-80 mm,with actual compression thickness equivalent to the average density of the breast compressed to 21-103 mm under full-field digital mammography(FFDM),low-dose mammography and digital breast tomosynthesis(DBT)exposure modes.The CoV of SNR in 2D images and tomosynthesis images was calculated for different mammographic devices under different exposure modes and compression thicknesses.Results:Between the compression thicknesses equivalent to the average density of the breast from 21 mm to 103 mm under FFDM,low-dose mammography,and DBT exposure modes,the differences in SNR CoV of 2D images under different exposure modes among mammographic devices 1,2,and 3 were statistically significant only in the DBT exposure mode(P=0.003),with SNR CoV ranging from 0.188%to 0.720%,0.368%to 1.073%and 0.402%to 1.662%,respectively.There were no statistically significant differences in SNR CoV of 2D images among devices 1,2,and 3 under FFDM and low-dose exposure modes(P=0.060).Under the DBT exposure mode,there were no statistically significant differences in the SNR CoV of the first projection image and the 0° projection image of tomosynthesis among devices 1(2 angles),2,and 3(P=0.373,P=0.742,P=0.225,P=0.693,respectively).Conclusion:The SNR CoV in 2D images and tomosynthesis images varies under different mammographic devices and exposure modes,with no fixed or standard values,but all within the required range for mammographic device quality control.The stability and repeatability of 2D images of mammographic devices are better under FFDM and low-dose exposure modes;the SNR CoV values of the first projection image and the 0° projection image of tomosynthesis under the DBT exposure mode show no statistical differences,indicating good stability of the devices.

Background and purpose:In the quality control of mammography,the signal-to-noise ratio(SNR)refers to the ratio of the useful signal intensity to the background noise in the image,which is one of the important indicators for measuring the quality of the image.The coefficient of variation(CoV)is a commonly used indicator to describe the consistency and repeatability of SNR.This study aimed to assess the stability and repeatability of mammographic device performance by analyzing the changes in SNR CoV in two-dimensional(2D)images and tomosynthesis images(referred to as Tomo images)under different exposure modes using three mammographic devices from different manufacturers.Methods:A polymethylmethacrylate(PMMA)phantom designed for mammography quality control was used to perform automatic exposure detection at PMMA thicknesses ranging from 20-80 mm,with actual compression thickness equivalent to the average density of the breast compressed to 21-103 mm under full-field digital mammography(FFDM),low-dose mammography and digital breast tomosynthesis(DBT)exposure modes.The CoV of SNR in 2D images and tomosynthesis images was calculated for different mammographic devices under different exposure modes and compression thicknesses.Results:Between the compression thicknesses equivalent to the average density of the breast from 21 mm to 103 mm under FFDM,low-dose mammography,and DBT exposure modes,the differences in SNR CoV of 2D images under different exposure modes among mammographic devices 1,2,and 3 were statistically significant only in the DBT exposure mode(P=0.003),with SNR CoV ranging from 0.188%to 0.720%,0.368%to 1.073%and 0.402%to 1.662%,respectively.There were no statistically significant differences in SNR CoV of 2D images among devices 1,2,and 3 under FFDM and low-dose exposure modes(P=0.060).Under the DBT exposure mode,there were no statistically significant differences in the SNR CoV of the first projection image and the 0° projection image of tomosynthesis among devices 1(2 angles),2,and 3(P=0.373,P=0.742,P=0.225,P=0.693,respectively).Conclusion:The SNR CoV in 2D images and tomosynthesis images varies under different mammographic devices and exposure modes,with no fixed or standard values,but all within the required range for mammographic device quality control.The stability and repeatability of 2D images of mammographic devices are better under FFDM and low-dose exposure modes;the SNR CoV values of the first projection image and the 0° projection image of tomosynthesis under the DBT exposure mode show no statistical differences,indicating good stability of the devices.

Objective To investigate the application value of low-molecular-weight heparin calcium combined with alprostadil in the treatment of hypoparathyroidism(HP)after thyroid surgery.Methods Sixty patients with HP after thyroid surgery were randomly divided into two groups:study group(30 cases)and control group(30 cases).The study group received low-molecular-weight heparin calcium and alprostadil,along with oral calcium supplements and calcitriol or an intravenous infusion of calcium gluconate,for three consecutive days after surgery.The control group received only oral calcium supplements and calcitriol or intravenous calcium gluconate.The values and changes in parathyroid hormone(PTH),postoperative drainage volume,and postoperative complications were compared between two groups.Results There were no significant difference in PTH levels at 3 days,1 week,1 month,and 6 months after surgery between two groups(P＞0.05).The difference in PTH levels between 3 days and 1 day after surgery was(6.77±2.61)ng/L in study group and(1.29±1.12)ng/L in control group,with a significant difference(P＜0.05).The difference in PTH levels between 1 week and 1 day after surgery was(10.51±3.66)ng/L in study group and(2.65±2.17)ng/L in control group(P＜0.05).There were no significant difference in PTH levels at 1 month,6 months,and 1 day after surgery(P＞0.05).Comparison of postoperative drainage volume:The postoperative drainage volume of study group was(90.07±22.24)ml,and that of control group was(88.20±24.09)ml,with no statistical significance(P＞0.05).There was no significant difference in postoperative complications between two groups(P＞0.05).Conclusion In cases of HP after total thyroidectomy,timely use of low-molecular-weight heparin calcium and alprostadil can accelerate the recovery of PTH and reduce patient numbness,which is safe,effective,and worthy of clinical promotion.

Objective:To describe the baseline characteristics of the subjects enrolled in the China Quantitative CT (QCT) big data program in 2018—2019.Methods:Based on baseline data from the Chinese health big data project from January 2018 to December 2019 from the eligible enrolled population, measurements of bone mineral density (BMD) and visceral adipose tissue (VAT) were performed using Mindways′ QCT Pro Model 4 system. The baseline data of age, gender, regional distribution, height, weight, abdominal circumference, blood pressure, blood routine and blood biochemical tests were analyzed. And the single factor analysis of variance (ANOVA) was used to check the age related trend of BMD and VAT in both genders.Results:After screening the inclusion exclusion criteria and outliers of the main indicators, 86 113 people were enrolled in the project. The enrollment rate was 92.47%, including 35 431 (41.1%) women and 50 682 (58.9%) men, and the ratio of men to women was 1.43. The mean age was (50.3±12.7) years in all the subjects, and it was (50.2±12.8) years and (50.4±12.5) years in men and women, respectively, and there was no statistical difference between the two genders ( P>0.05). Total of 43 833 people were enrolled in east China, it was the largest group by region (50.90%), it was followed by central China (16 434 people, 19.08%), and the number of people enrolled in Northeast China was the lowest (2 914 people, 3.38%). The rate of completing of health information indicators related to the main outcome of the study were all above 70%, and there were significant differences between men and women (all P<0.05). The mean BMD was (139.33±46.76) mg/cm 3 in women, (135.90±36.48) mg/cm 3 in men, which showed a decreasing trend with age in both gender (both P<0.001); the mean intra-abdominal fat area was (116.39±56.23) cm 2 in women, (191.67±77.07) cm 2 in men, and there was an increasing trend with age in both men and women (both P<0.001). Conclusions:There are gender differences in BMD and VAT measured by QCT with different age tendency, and there are gender differences in health information index. Regional factors should also be taken into account for regional differences in the inclusion of data.

Objective:To investigate the normal reference values of spinal bone mineral density measured by quantitative computed tomography (QCT) and the differences of bone mineral density (BMD) in different regions of in Chinese adult males.Methods:Men who underwent low-dose CT lung scan for cancer screening in regions of Northeast, North, East, South, Central and Southwest of China from January 2018 to December 2019 were selected. And the lumbar vertebrae BMD values in the male subjects were measured by the QCT system (Mindways Software, Inc.). The mean BMD values and their decline rates were calculated at an age interval of 10 years, and the prevalence of osteoporosis was calculated according to the American College of Radiology spine QCT osteoporosis diagnostic criteria.Results:A total of 50 682 males with a mean age of (50.22±12.79) years (ranged 20 to 98 years) were included in this study. The peak BMD of (173.11±28.56) mg/cm 3 in the healthy Chinese adult male population appeared in the age group of 20 to 29 years and then declined with age. Before the age of 70 years, the BMD was relatively higher in males in South China, and it was lower in Central China and Southwest China, and it was intermediate in Northeast, North and East of China, with statistically significant differences. There was no significant differences in BMD in the males in the two age groups of 70 to 79 years and 80 and older among the regions in China. The overall decline rate of spinal BMD in Chinese males under QCT was about 46.92% over the lifetime, and it declined obviouslyin the 40-49 age group. The overall prevalence of osteoporosis in Chinese male population aged 50 years and above was approximately 11.42%, with the highest prevalence in Southwest China and Central China (14.72% and 13.87%, respectively) and the lowest in North China and South China (8.53% and 7.71%, respectively). Conclusions:A reference of lumbar spine BMD values for healthy males in China based on QCT is established. BMD values were highest in South China and Lowest in Central China.

Objective:To establish the normal reference value of lumbar bone mineral density (BMD) under quantitative CT (QCT) in Chinese healthy adult females and to explore the regional differences.Methods:Total of 35 431 healthy women who met the inclusion criteria of Chinese health quantitative CT big data program were selected in this study. The BMD of the central plane of L 1 and L 2 vertebrae was measured by Mindways′s QCT system, and the mean value was taken. One-way analysis of variance was used to compare the BMD differences of lumbar vertebrae in women of different ages and regions. The subjects were grouped by an age interval of 10 years, and the level of BMD in different regions of the same age group were compaired. Results:The peak BMD of Chinese healthy adult women appeared in the age group of 20-29 years (Northeast China(183.01±24.58) mg/cm 3, North China (188.93±24.80) mg/cm 3, East China (187.54±27.71) mg/cm 3, South China (186.22±33.72) mg/cm 3, Central China (176.33±24.91) mg/cm 3, Southwest China(182.25±28.00) mg/cm 3), and then it decreased with age. The level of BMD in different regions decreased with the age. Before the age of 70 years, BMD in Central and Southwest China was always at a low level((176.23±24.91) to (90.38±28.12) mg/cm 3, 182.25±28.00 to (88.55±25.68) mg/cm 3), lower than those in Northeast China ((183.01±24.58) to (99.69±27.85) mg/cm 3), North China ((188.93±24.80) to (95.89±26.12) mg/cm 3), East China ((187.54±27.71) to (95.65±27.86) mg/cm 3). After 70 years of age, BMD tended to be the same in different regions ( P>0.05). The BMD values in Central China and Southwest China were similar in the age group of 40-60 years ( P>0.05). The BMD values in the health adult femles in the age group of 60 years in different regions of Chinawere all lower than those of bone mass abnormality (all P<0.05). The detection rate of osteoporosis in females over 50 years was the highest in Southwest China (25.65%) and it was the lowest in North China (17.30%). Conclusions:This study establishes reference values of BMD under QCT in healthy Chinese women, which can be used as a reference basis for identifying women with low BMD who are at risk of osteoporosis. The BMD value is the lowest in Southwest China and the highest in South China.

Objective:To use quantitative computed tomography (QCT) technology to measure the bone mineral density of the spine of the Chinese healthy population, and to explore its correlation with hemoglobin and serum albumin.Methods:The data in this study came from the China Health Quantitative CT Big Data Project (China Biobank). The spine bone density was measured by using QCT Pro Image Analysis System and all cooperating centers used the European spine phantom (NO.145) for quality control. Total of 50 053 healthy persons who met the criteria for entry were selected as the research subjects. The subjects were divided into 7 groups according to age. The general data, spine bone density, serum albumin, hemoglobin of the subjects were collected. The single-factor analysis of variance, Pearson correlation analysis and multi-classification logistic regression model were applied to analyze the correlation between bone density and hemoglobin and serum albumin.Results:The bone mineral density of healthy people decreased with age ( P<0.05), and there were significant differences in hemoglobin, serum albumin and body mass index (BMI) among different age groups (all P<0.05). Linear correlation analysis showed that there were positive correlation between bone mineral density and hemoglobin in healthy males in different age groups ( r=0.086, 0.101, 0.076, 0.090, 0.072, 0.123, 0.100, all P<0.01). There were negative correlation between bone mineral density and hemoglobin in certain age groups in women (40-49 years group: r=-0.027; 70-79 yearsgroup: r=-0.077; both P<0.05). And corelation were found between bone mineral density and serum levels of albumin in certain age groups of healthy subjects (among men, 30-39 years group: r=-0.048; 40-49 years group, r=-0.027; 70-79 years group, r=-0.051; among women, 30-39 years group: r=-0.044; 40-49 years group, r=-0.042; 50-59 years group, r=-0.086; 70-79 years group, r=-0.070; all P<0.05). After adjusting for age and BMI, the multi-category logistic regression analysis showed that the hemoglobin level was protective factor of normal bone density ( OR=1.022, 95% CI:1.017-1.027) and decreased bone density ( OR=1.012, 95% CI:1.007-1.016) in healthy males, and the serum albumin was risk factor for normal bone density ( OR=0.926, 95% CI:0.905-0.948) and decreased bone density ( OR=1.006, 95% CI:0.951-1.011) in healthy women. Conclusion:There is a correlation between bone mineral density and hemoglobin and serum albumin in Chinese healthy population. Hemoglobin is a protective factor for bone mineral density in men, and serum albumin is a risk factor for bone mineral densityin women.

Objective:To investigate the relationship between abdominal visceral adipose tissue (VAT) and cardiometabolic risk (CMR) through quantitative computed tomography (QCT).Methods:The present study included 76226 participants. Abdominal fat areas were measured using the QCT Pro Model 4 system. Cardiometabolic indices were collected, including systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, triglyceride, and low-density and high-density lipoprotein cholesterols CMR score was the sum of abnormal blood pressure, fasting glucose, triglyceride, and high-density lipoprotein cholesterol. Restricted cubic spline and ordered logistic regression models were applied.Results:The mean age was 50±13 years and the percentage of men was 58.8%. The level of VAT area was higher in men than in women (191.7±77.1 cm 2 vs 116.4±56.2 cm 2, P<0.0001 for all). After adjustment for age, the cardiometabolic indices except high-density lipoprotein cholesterol increased with increasing VAT area. When VAT area was 300 cm 2, age-adjusted odds ratios and 95% confidence intervals of a CMR score ≥ 1 were 14.61 (13.31, 16.04) for men and 5.46 (4.06, 7.36) for women, and the age-adjusted probability of a CMR score ≥ 3 was 31.7% for men and 31.3% for women. Conclusions:QCT-derived VAT is closely related to CMR. The findings suggest that measurement of visceral fat is recommended for the management of abdominal obesity in subjects who agree to undergo lung cancer screening via low-dose CT without additional radiation exposure.

Objective To analyze the characteristics and to evaluate the application of quantitative CT spectral parameters in patients with suspected lung cancer.Methods One hundred and thirty two patients with occupying lesions of the lung underwent chest plain and two-phase contrast enhanced CT scan with gemstone spectral imaging (GSI) mode.The CT images of patients with confirmed lung cancer by pathological evidence were analyzed with GSI viewer.Optimal energy value supplying optimal contrast-tonoise ratio (CNR) was recorded.The CT values of lesions at 40 keV,70 keY and optimal energy level were measured.Spectral curve slope at different intervals of 40-70 keV,40-100 keV and 40-140 keV was computed.Effective atomic number (Zeff),iodine concentration (IC) and water concentration (WC) were measured and analyzed by statistical methods.Results Sixty six patients with confirmed lung cancer were included in the analysis.The optimal energy values for optimal CNR on plain scan,arterial phase and venous phase were (63.09±5.33) keV,(52.65±6.44) keV and (54.06±5.53) keV,respectively.The difference of CT values at different energy levels on each scan phase was statistically significant (F=4.561,P=0.025).The spectral curve slope values among three different energy intervals were significantly different (F=2.137,P＜0.001).The differences of the slope between arterial phase and venous phase at same energy interval were not significant (40-70 keY:t=1.165,P=0.248;40-100 keV:t=1.102,P=0.274;40-140 keV:t=1.118,P=0.268).Zeff on plain scan,arterial phase and venous phase was 7.73±0.14,8.35±0.37 and 8.39±0.30,respectively.There was positive correlation between IC and Zeff on enhanced phase (arterial phase:r=0.998,P＜0.001;venous phase:r=0.998,P＜0.001).Conclusion CT spectral imaging can supply the optimal energy value for optimal CNR.CT value at optimal energy level and spectral curve slope at 40-140 keV are suitable for analysis.IC and Zeff can be used jointly in evaluation of patients with suspected lung cancer.

OBJECTIVE:To develop a method for simultaneous determination of geniposide,baicalin,aloe-emodin,rhein, emodin,chrysophanol and physcion in Zhizi jinhua dispersible tablets. METHODS:HPLC method was adopted. The determination was performed on Dimonsil C18 column with mobile phase consisted of methanol-0.05%phosphoric acid(gradient elution)at the flow rate of 0.8 mL/min. The detection wavelength was set at 254 nm,and the column temperature was 25℃. The sample size was 20 μL. RESULTS:The linear ranges of geniposide,baicalin,aloe-emodin,rhein,emodin,chrysophanol and physcion were 0.0323-0.323 μg (r=0.9998),0.1374-1.374μg(r=0.9999),0.00372-0.0372μg(r=0.9997),0.0069-0.069μg(r=0.9995),0.00332-0.0332μg (r=0.9997),0.00864-0.0864 μg(r=0.9997) and 0.00122-0.0122 μg(r=0.9995),respectively. The limits of quantitation were 0.0321,0.1374,0.00372,0.0067,0.00330,0.00864,0.00122 μg,respectively. The limits of detection were 0.0095, 0.0041,0.0012,0.0020,0.0010,0.0026,0.0003 μg,respectively. RSDs of precision,stability and reproducibility tests were all lower than 3%. The average recoveries were 96.54%-99.52%(RSD=1.17%,n=6),97.23%-101.23%(RSD=1.36%,n=6), 97.22%-101.25%(RSD=1.83%,n=6),97.32%-100.23%(RSD=1.09%,n=6),97.99%-102.71%(RSD=1.73%,n=6), 96.99%-100.23%(RSD=1.21%,n=6),96.99%-103.01%(RSD=2.31%,n=6),respectively. CONCLUSIONS:The methods is simple and reproducible. It can be used for the content determination of 7 components in Zhizi jinhua dispersible tablets.