RESUMEN
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.
RESUMEN
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.
RESUMEN
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.
RESUMEN
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.
RESUMEN
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.
RESUMEN
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.
RESUMEN
Objective Analysis of myocardial microvascular perfusion in patients with chronic total coronary occlusion (CTO) who underwent a coronary artery bypass graft (CABG) use real-time myocardial contrast echocardiography (RTMCE),to provide an effective method of detecting viable myocardium and a reference for the choice of CABG indications.Methods Twenty-seven patients with CTO underwent RTMCE 1 week before CABG,they underwent follow-up echocardiography and coronary artery 256-slice multislice computed tomography aagiography 1 year after CABG.Myocardial viability was defined as a postoperative ultrasound wall motion significantly improved ≥ 1 point.Semi-quantitative analysis of contrast images,myocardial viability was defined as myocardial perfusion score ≤ 2 points.Viable myocardium by quantitative assessment of myocardial blood flow (MBF) was determined by analyses of receiver-operating characteristic (ROC) curves.Results Patients with LVEF increased significantly after CABG (P ＜ 0.01),Of 259 segments with wall motion abnormality,149 (58％) showed wall motion significantly improved ≥ 1 point after CABG,considered viable myocardium,110 (42％) were not observed in wall motion improved,considered to be non-viable.The viable myocardial segments were significantly greater than non-viable myocardial segments in A,β,A × β value (P ＜ 0.01).Compared with the semi-quantitative analysis,quantitative analysis of MBF increased the sensitivity and accuracy of RTMCE for detecting viable myocardium (P ＜ 0.05).Conclusion RTMCE could accurately assess myocardial viability and provide a strong reference for clinical decision making and judging prognosis.
RESUMEN
Objectives To evaluate the effectiveness of bedside noninvasive scoring system in diagnosis of coronary heart disease (CAD).MethodsSix hundred and twelve patients with suspected CAD in our hospital were enrolled (343 males and 269 females) from September 2008 to October 2010,with an average age of 55 ± 7 y.The detailed history was taken; physical examination,resting electrocardiogram,blood biochemistry,treadmill exercise test and/or 12 lead Holter monitoring,64 or 256 rows CT coronary artery imaging and coronary artery angiography were performed in all patients.The risk factors for CAD were screened by multiple questionnaire surveys with Delphi method.The risk factors were stratified according to the results of expert survey: heavy smoking,diabetes mellitus,typical angina,positive treadmill exercise test and positive Holter monitoring electrocardiogram were included in the highest risk factors with an integrated scores of 8 ; dyslipidemia of 3 items,hypertension complicated with left ventricular hypertrophy were high risk factors with an integrated scores of 6; males≥40 y,medium smoking,dyslipidemia of 2 items,pathoglycemia,heavy drinking,positive ECG and post-menopause females were moderate risk factors with integrated scores of 4; Low risk factors contain moderate drinking and dyslipidemia of item,were classified as low risk factors with an integrated scores of 2. The bedside noninvasive scoring system was evaluated in all patients and the results were compared with those from multi-slice spiral CT or coronary angiography.ResultsWhen integrated score ≥ 24 was set as the cut-off level for diagnosis of CAD,thesensitivity,specificity,positive predictive value and accuracy were 89.95％,85.63％,94.03％and 88.73％ respectively.When integrated score≤ 14 was set as the exclusion criteria of CAD,the sensitivity,specificity,positive predictive value and accuracy were of 93.10％,82.86％,98.09％ and 84.80％ respectively.The accuracy was lower than that of multi-slice spiral CT or coronary angiography( P ＜0.05 ).ConclusionsThe bedside noninvasive scoring system is effective for preliminary diagnose of CAD,but need to be further improved.
RESUMEN
Objective To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current control (CCC) and explore a more reasonable scanning protocol. Methods Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (A1) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (C1) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols.The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically.Differences of radiation dose and noise among groups were determined with variance analysis and t test,image quality with Mann-Whitney test and the consistency of diagnosis with Kappa test. Results There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31)vs ( 110.81±18.21) mGy·cm (F =56. 88 ,P ＜ 0. 01 )], whereas no significant difference was observed between group A2 and group A1 0. 05]. The noisy of AEC group was higher than that of CCC group both on lung window(41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference( Flung =0.835, P=0.476, Fmediastinum =1.910, P=0.128).The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49±0.56 vs4.38±0.64,superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32,the right superior lobar bronchus Level:4.87±0.27 vs 4. 84 ± 0. 22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level(4. 92 ±0. 25 vs 4. 93 ±0. 17) and superior margin of the left diaphragmatic dome level (4. 91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P＞0.05) were observed. A significant higher score in AEC group was observed on mediastinum window compared with CCC group on superior margin of brachiocephalic vein level (2.57±0.77 vs 2. 46 ± 0. 59, F = 8. 459, P ＜ 0. 05 ), however, the score of AEC group was lower than that of CCC group on other levels without significant differences (superior margin of the aortic arch:3.36 ±0. 63 vs 3.45 ±0. 60,the right superior lobar bronchus level: 3.94 ±0. 56 vs 3. 95 ±0. 51 ,the right middle lobar bronchus Level: 3.80 ±0. 58 vs 3. 87 ±0. 50,the right inferior pulmonary vein level: 3.72 ±0. 56 vs 3.78 ±0. 53, superior margin of the left diaphragmatic dome level: 3.58 ± 0.63 vs 3.68±0.56,F=0.083-3.380,P ＞ 0.05 ). The MPR image quality of AEC group was better than that of CCC group both on lung window and mediastinum window (Zlung =-2.258, Zmedlastinum=-1.330, P＞0.05). For all participants including the underweighted group, the normal group and the overweighted group, the image quality of A1 group was better than that of A2 group without significant differences (the underweighted group: Zlung=0.000, P=1.000, Zmedastinum= 0.000, P=1.000;the normal group: Zlung =-0.062, P=0.950, Zmediastinum =-0.746, P = 0.456; the overweighted group: Zlung = - 1.177, P = 0.239,Zmediastinum =-1.715, P=0.144) both on lung and mediastinum windows, and for the higher BMI participants, a better image quality was obtained in A1 group than in A2 group on the mediastinum window (Z = -1. 715, P = 0. 144). Conclusions The total radiation exposure dose of AEC group is significantly lower than that of CCC group, but no statistical significant differences are observed between both groups in image quality and noise level. The AEC technique is highly recommended in thoracic LDCT scan for screening program, and the SD25 ( SD value = 25) scan protocol is suggested for higher BMI population while the SD30 (SD value = 30) scan protocol for lower BMI population.
RESUMEN
Objective To study the hemodynamic changes of rabbit VX2 liver tumors before and after ethanol injection by perfusion imaging of MSCT and investigate the correlation between perfusion parameters and microvessel density (MVD). Methods All of 15 Japanese long-ear white rabbits were divided into control group and experiment group. All rabbits were inoculated with VX2 liver tumor. Perfusion imaging of MSCT scans were conducted in 5 rabbits in the control group on the 14 th day after VX2 tumor inoculation, and the borders of the tumors were stained with immunohistochemical stains, and MVD was measured by anti-CD34. Perfusion imaging of MSCT scans were conducted in all 10 rabbits in the experiment group on the 14 th day after VX2 tumor inoculation. Then absolute alcohol was injected into the tumors by laparotomy. CT scans were conducted 3 and 30 days after absolute alcohol injection, and the borders of the tumors were stained immunohistochemically, and MVD was measured by anti-CD34. The differences of perfusion parameters such as hepatic blood ( BF), hepatic blood volume (BV), mean transit time ( MTT),permeability of capillary vessel surface (PS), and hepatic arterial fraction (HAF), hepatic arterial perfusion (HAP) were compared to evaluate the liver hemodynamic changes. Statistical repeated measurement t test, correlation analysis were performed. Results BF of border of the tumor between pretreatment, 3 days after ethanol injection and 30 days after ethanol injection were ( 280. 62 ± 59. 87 ),(322.03 ± 86. 94 ), ( 177.05 ± 75.96) ml · min -1; HAF were 0. 59 ± 0. 08, 0. 89 ± 0. 12, 0. 23 ± 0. 07;HAP were ( 189. 26 ± 25.46), ( 251.57 ± 31.78 ), (40. 90 ± 5.17 ) ml · min - 1 · ml - 1. HAP increased significantly after ethanol injection 3 days ( P ＜ 0. 05 ); BF, HAF, HAP decreased significantly 30 days after ethanol injection compared with 3 days after ethanol injection ( P ＜ 0. 05 ); BF, HAF, HAP decreased significantly 30 days after ethanol injection compared with pre-treatment ( P ＜ 0. 05 ). It showed positive correlation between BF, PS, HAF, HAP and MVD (r=0. 916, 0. 726, 0. 870, 0. 889; P ＜0. 05). MVD decreased significantly compared with the control group (43.9 ± 4. 0)/HP 30 days after ethanol injection (21.8±3.5)/HP (t = 12.271, P ＜0.05). Conclusion Perfusion imaging of MSCT can detect the hemodynamic changes in rabbit VX2 liver tumors, and also in tumors before and after ethanol injection. CT perfusion can take the place of MVD to evaluate the tumor angiogenesis.