0.05) The correlation coefficients were 0 52-0 96 (2) The correlation coefficients of left ventricular mass(EDM and ESM) among three methods were lower than those of left ventricular volume ,and there was statistically significant difference in ESM between MRI and echocardiography( P

Objective To probe into the value of MR imaging in evaluating the pulmonary artery hemodynamics and pulmonary artery pressure in acute massive pulmonary embolism.Methods MR studies were performed in 21 patients with acute massive pulmonary embolism (diagnosed by contrast enhanced MR pulmonary angiography) and 20 healthy volunteers. The pulmonary artery hemodynamic parameters, such as the diameters of main and right pulmonary artery, peak velocity, average velocity, flow volume, flow patterns, and ejection acceleration time in main pulmonary artery were measured. The findings in patients and volunteers were compared. The hemodynamic parameters in patients were correlated with mean pulmonary artery pressure acquired with right heart catheterization.Results The diameters of main pulmonary artery (2.93 vs 2.52 cm) and right pulmonary artery (2.49 vs 1.92 cm) in patients and volunteers showed significant differences (t=3.55, P

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.

Objective To evaluate the difference and correlation of 24-hour energy expenditure in patients with multiple trauma receiving mechanical ventilation predicted by indirect calorimetry (IC) and HB formula. Methods 140 patients with multiple trauma receiving mechanical ventilation admitted to intensive care unit (ICU) of the General Hospital of Ningxia Medical University from December 1st, 2016 to August 31st, 2017 were enrolled. The 24-hour energy expenditure of patients was repeatedly measured at 1, 3, 5, and 7 days after ICU admission by IC method, and the 24-hour energy expenditure measured by IC method was used as the "gold standard" to calculate the 24-hour kilogram body weight energy expenditure. The 24-hour energy expenditure value measured by IC method was compared with the 24-hour energy expenditure predicted value calculated by HB formula method, the consistency of the two measurement methods was detected by Bland-Altman method, and the correlation between the two measurement methods was analyzed by Pearson method and the linear equation was fitted. Results The 24-hour energy expenditure of patients at 1, 3, 5 and 7 days after ICU was repeatedly measured by IC method for 501 times, and there was no significant difference in 24-hour energy expenditure (kJ/d: 8 163.1±1 599.4, 8 221.1±1 694.7, 8 445.8±1 756.4, 8 707.0±1 820.7, respectively, F = 2.451, P = 0.063) and 24-hour kilogram body weight energy expenditure (kJ·kg-1·d-1: 120.5±18.9, 121.4±19.7, 122.7±19.3, 121.4±19.3, respectively, F = 0.252, P = 0.860) at each time point, indicating that the first week of multi-injury patients had no significant changes in energy metabolism. The consistency between the 24-hour energy expenditure measured by IC method on the first day [(8 163.1±1 599.4) kJ/d] and that predicted by HB formula method [(6 568.8±782.0) kJ/d] was analyzed. The results showed that there was significant bias between the two methods, with an average bias of -(1 591.8±121.4) kJ/d, but the correlation analysis showed that there was a linear correlation between them (r = 0.439, P = 0.000), using one-way regression, the fitted linear equation was Y = 2 270.5+0.897X (X was 24-hour energy expenditure predicted by the HB formula). Conclusions The energy metabolism of patients with multiple trauma receiving mechanical ventilation is not obvious within 1 week. The HB formula method underestimates the 24-hour energy expenditure of patients. The prediction formula can be used to correct the HB formula and further to improve the accuracy of predicting the 24-hour energy consumption of patients.

objective:To evaluate the difference 24h energy expenditure in patients with multiple trauma mechanical ventilation predicted by indirect calorimetry (IC) and HB formula. To explore the correlation between energy expenditure and Injury Severity Scoring (ISS) in patients with multiple trauma, and to predict the stress coefficient to improve the accuracy of HB prediction.Methods:A total of 152 patients with multiple trauma receiving mechanical ventilation were included in the ICU of the General Hospital of Ningxia Medical University during December 1st, 2016 to August 31st, 2018. As a research object, The IC method and the HB method were used to simultaneously measure the patient's 24h energy expenditure, and the difference between the two measurement methods was compared. The 24h energy consumption measured by the IC method was used as the "gold standard", and the 24h body weight energy expenditure per kilogram was calculated; Grouped according to the ISS score, compared 24h energy consumption with 24h body weight energy expenditure per kilogram. The Bland-Altman method was used to test the consistency of the two measurements. The two groups were compared using t test, the correlation was analyzed by pearson correlation, and the regression equation was linearly calculated by linear regression.Results:There was a significant bias between the IC method and the HB method in measuring the 24h energy expenditure of patients with multiple trauma, with an average bias of 394.0± 54.0Kcal/d. The 24h energy consumption and 24h body weight energy expenditure per kilogram in the severe injured group were significantly higher than those in the moderate injury group ( P<0.05). The stress coefficient was calculated, The stress coefficient of the HB method associated with the ISS using the one-way regression was Y=0.770+0.018×ISS. Conclusion:The HB method significantly underestimates the 24h energy expenditure of patients with multiple trauma . In order to improve the accuracy of the HB method to predict the 24h energy consumption of patients with multiple injuries, The HB method can be corrected using the stress coefficient associated with the ISS score, Y = (0.770 + 0.018 × ISS) × HB method.

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.

Objective:To evaluate the predictive effect of the 24 h energy expenditure value obtained by indirect calorimetry (IC) on the prognosis of patients with multiple traumatic mechanical ventilation.Methods:A total of 140 patients with multiple traumatic mechanical ventilation who were hospitalized in the ICU of General Hospital of Ningxia Medical University from December 1st, 2016 to August 31st, 2018 were selected as research objects. The general information such as sex, age, Height, weight, and clinical diagnosis were recorded. The IC method was used to measure the patient's 24 h energy expenditure, and the ratio of 24 h energy expenditure to the actual body weight of the patients was calculated the energy expenditure of 24 h energy expenditure per kilogram of body weight. The patient’s mechanical ventilation time and length of stay in ICU were statistically analyzed. The outcome indexes were 28-day mortality and the incidence of hospital-acquired infection. The receiver operating characteristic curve (ROC) was used to analyze the predictive value of 24 h energy expenditure and 24 h energy expenditure per kilogram of body weight.Results:The mechanical ventilation time was positively correlated with 24 h energy expenditure and 24 h energy expenditure per kilogram of body weight ( r=0.470, r=0.247, both P<0.01). The length of sty in ICU was positively correlated with the 24 h energy expenditure of patients with multiple trauma( r=0.276, P<0.05). The area under the ROC curve (AUC) of the 24 h energy expenditure and 24 h energy expenditure per kilogram of body weight for the 28 d mortality and the incidence of hospital-acquired infection were 0.647, 0.663, 0.832, 0.646, with the 24 h energy expenditure per kilogram of body weight greater than 30.4 kcal/(kg·d) as the best critical value for judging 28 d mortality. The sensitivity was 66.5%, specificity was 77.0%, and the 24 h energy expenditure consumption greater than 2 083 kcal/d was used as the optimal critical value for judging the susceptibility to acquire hospital infection, with a sensitivity of 80.0% and specificity of 80.7%. Conclusions:The mechanical ventilation time and length of stay in ICU are closely related to energy expenditure in patients with multiple trauma. The 24 h EE per kilogram of body weight and 24 h energy expenditure have a certain predictive effect on the prognosis of patients with multiple trauma.

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 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.