Objective:To evaluate the short-term precision and accuracy of bone mineral density (BMD) measured with quantitative CT (QCT) and dual-energy X-ray absorptiometry (DXA) in multi-centre clinical research with a European spine phantom (ESP).Methods:From January 2016 to April 2020, totally 40 CT scanners (12 Siemens from Germany, 12 Philips from Netherlands, 9 GE from US, 5 Toshiba from Japan, 2 United Imaging from China) and 53 DXA instruments (34 GE Lunar from US, 14 Hologic from US, 5 Medlink from France) used in multi-centre in China were enrolled. The CT equipment came from 31 centers and DXA equipment from 32 centers.Using Mindways QCT software, the ESP was scanned 10 times on each instrument with repositioning using standardized spine protocols with QCT and DXA. The BMD value of the three lumbar vertebrae with low, medium, high density and the mean BMD value were measured. Accuracy was assessed by comparing BMD values measured on each device with the actual value of the phantom. Short-term precision was calculated as the root-mean-square standard deviation (RMS-SD) and root-mean-square standard deviation coefficient of variation (RMS-%CV) for the repeated measurements. The repeated measures variance analysis was used to compare the differences in BMD between different devices.Results:The differences in BMD values were statistically significant among different CT and DXA devices.The ranges of the accuracy measured by different QCT devices were 1.20% to 7.60% for Siemens, -1.83% to 0.20% for Philips, 1.18% to 13.20% for GE, -0.12% to 3.55% for Toshiba, -1.65% to 6.32% for United Imaging, 6.59% to 21.34% for GE Lunar, -6.65% to 5.45% for Hologic, and -6.97% to -0.68% for Medlink, respectively. The RMS-%CV of all vertebral BMD values measured by QCT and DXA ranged from 0.38% to 3.85%. The RMS-SD of QCT was 0.54 to 2.45 mg/cm 3, of DXA was 0.009 to 0.037 g/cm 2. The RMS-%CV values of each vertebral body measured by different QCT and DXA devices decreased with the increase of BMD, while the RMS-SD values showed the opposite tendency. Conclusions:Based on ESP, the QCT and DXA devices have significant differences in lumbar spine BMD measurement. Comparing the measurement results among different devices requires cross-calibration. Overall, the accuracy and short-term precision are within a reasonable range, which can be used for clinical follow-up observation. The short-term precision error and accuracy error range of QCT in evaluating the density of ESP were slightly smaller than those of DXA.

Objective To explore the change patterns in the lumbar vertebral bone marrow fat content with age, analyze the interactions between lumbar vertebral bone marrow fat content, bone mineral density (BMD), and age, and compare the difference of lumbar vertebral bone marrow fat content between males and females in the same age groups. Methods According to the statistical sample size requirements that the minimum sample size of each group was 18, thus, we prospectively recruited healthy volunteers who met the inclusion criteria. Among them, there were 139 males and females, with age range of 21-70 years old. According to age, the patients were divided into group 1 (21-30-yr), group 2 (31-40-yr), group 3 (41-50-yr), group 4 (51-60-yr), and group 5 (61-70-yr). Quantitative computed tomography (QCT) was used to measure the lumbar vertebral BMD, and MR mDIXON-Quant technique was used to measure the marrow fat content of L3 lumbar vertebra. We compared the difference of lumbar vertebral bone marrow fat content and BMD between different age groups in males and females using one-way ANOVA, and compared the difference of lumbar vertebral bone marrow fat content and BMD between males and females in the same age groups using t-test. Correlation analysis was conducted between bone marrow fat content, BMD and age. Results Lumbar vertebral bone marrow fat content was generally increasing with the age. There were significant differences in the fat content of bone marrow at different age groups (male, F=13.598, P=0.000;female, F=73.419, P=0.000). Before the age of 50 years, lumbar vertebral bone marrow fat content in females was lower than one in males, and there was a significant difference between group 2 [females,(29.7± 7.1)%-(36.1 ± 6.6)%, males,(34.1 ± 8.4)%-(39.9 ± 5.9)%;21-30-yr, t=1.984, P=0.053;31-40-yr, t=5.699, P=0.000;41-50-yr, t=2.017, P=0.050]. Females older than 50 years had a higher marrow fat content than males, and there was a significant difference between group 5 [females,(48.3±8.8)%-(52.5±8.2)%, males, (45.5 ± 8.1)%-(46.2 ± 7.4)%;51-60-yr, t=-0.914, P=0.365;61-70-yr, t=-3.400, P=0.001]. For males, bone marrow fat content was positively correlated with age (r=0.527, P<0.05), and negatively correlated with BMD (r=-0.730, adjusted for age r=-0.584, P<0.05). For females, bone marrow fat content was positively correlated with age (r=0.761, P<0.05), and negatively correlated with BMD (r=-0.809, adjusted for age r=-0.473, P<0.05). Conclusions Lumbar vertebral bone marrow fat content was generally increasing with the age. Bone marrow fat content was positively correlated with age and negatively correlated with BMD for males and females.

Objective To explore the change patterns in the lumbar vertebral bone marrow fat content with age, analyze the interactions between lumbar vertebral bone marrow fat content, bone mineral density (BMD), and age, and compare the difference of lumbar vertebral bone marrow fat content between males and females in the same age groups. Methods According to the statistical sample size requirements that the minimum sample size of each group was 18, thus, we prospectively recruited healthy volunteers who met the inclusion criteria. Among them, there were 139 males and females, with age range of 21-70 years old. According to age, the patients were divided into group 1 (21-30-yr), group 2 (31-40-yr), group 3 (41-50-yr), group 4 (51-60-yr), and group 5 (61-70-yr). Quantitative computed tomography (QCT) was used to measure the lumbar vertebral BMD, and MR mDIXON-Quant technique was used to measure the marrow fat content of L3 lumbar vertebra. We compared the difference of lumbar vertebral bone marrow fat content and BMD between different age groups in males and females using one-way ANOVA, and compared the difference of lumbar vertebral bone marrow fat content and BMD between males and females in the same age groups using t-test. Correlation analysis was conducted between bone marrow fat content, BMD and age. Results Lumbar vertebral bone marrow fat content was generally increasing with the age. There were significant differences in the fat content of bone marrow at different age groups (male, F=13.598, P=0.000;female, F=73.419, P=0.000). Before the age of 50 years, lumbar vertebral bone marrow fat content in females was lower than one in males, and there was a significant difference between group 2 [females,(29.7± 7.1)%-(36.1 ± 6.6)%, males,(34.1 ± 8.4)%-(39.9 ± 5.9)%;21-30-yr, t=1.984, P=0.053;31-40-yr, t=5.699, P=0.000;41-50-yr, t=2.017, P=0.050]. Females older than 50 years had a higher marrow fat content than males, and there was a significant difference between group 5 [females,(48.3±8.8)%-(52.5±8.2)%, males, (45.5 ± 8.1)%-(46.2 ± 7.4)%;51-60-yr, t=-0.914, P=0.365;61-70-yr, t=-3.400, P=0.001]. For males, bone marrow fat content was positively correlated with age (r=0.527, P<0.05), and negatively correlated with BMD (r=-0.730, adjusted for age r=-0.584, P<0.05). For females, bone marrow fat content was positively correlated with age (r=0.761, P<0.05), and negatively correlated with BMD (r=-0.809, adjusted for age r=-0.473, P<0.05). Conclusions Lumbar vertebral bone marrow fat content was generally increasing with the age. Bone marrow fat content was positively correlated with age and negatively correlated with BMD for males and females.

OBJECTIVE: To investigate the bone mineral density (BMD) of cervical vertebrae in a population-stratified manner and correlate with that of the lumbar vertebrae. MATERIALS AND METHODS: Five hundred and ninety-eight healthy volunteers (254 males, 344 females), ranging from 20 to 64 years of age, were recruited for volumetric BMD (vBMD) measurements by quantitative computed tomography. Basic information (age, height, weight, waistline, and hipline), and vBMD of the cervical and lumbar vertebrae (C2-7 and L2-4) were recorded. Comparisons among sex, age groups and different levels of vertebrae were analyzed using analysis of variance. Linear regression was performed for relevance of different vertebral levels. RESULTS: The vBMD of cervical and lumbar vertebrae was higher in females than males in each age group. The vBMD of the cervical and lumbar vertebrae in males and the vBMD of lumbar vertebrae in females decreased with aging. In each age group, the vBMD of the cervical vertebrae was higher than that of the lumbar vertebrae with gradual decreases from C2 to C7 except for C3; moreover, the vBMD of C6 and C7 was significantly different from that of C2-5. Correlations of vBMD among different cervical vertebrae (females: r = 0.62-0.94; males: r = 0.63-0.94) and lumbar vertebrae (males: r = 0.93-0.98; females: r = 0.82-0.97) were statistically significant at each age group. CONCLUSION: The present study provided normative data of cervical vertebrae in an age- and sex-stratified manner. Sex differences in vBMD prominently vary with age, which can be helpful to design a more comprehensive pre-operative surgical plan.
Aging ; Asian Continental Ancestry Group* ; Bone Density* ; Cervical Vertebrae ; Female ; Healthy Volunteers ; Humans ; Linear Models ; Lumbar Vertebrae* ; Male ; Sex Characteristics ; Spine

Objective:To investigate the effects of probiotics on intestinal flora, intestinal function, and T lymphocyte level in patients with cervical cancer after radiotherapy.Methods:A total of 92 patients with cervical cancer who underwent pelvic radiotherapy in The Second Affiliated Hospital of Zhengzhou University from September 2020 to February 2022 were included in this study. They were randomly divided into control and experimental groups ( n = 46/group). The patients in the experimental group took probiotics during radiotherapy, while the patients in the control group did not take probiotics during radiotherapy. The amount of intestinal flora, D-lactic acid, diamine oxidase, and T lymphocyte subset levels pre- and post-radiotherapy were compared between the two groups. Urinary lactulose (L) and mannitol (M) concentrations were determined in each group. Urinary excretion ratios of L to M were calculated. Results:After 10, 15, and 20 times of radiotherapy and after all radiotherapies, the amount of Escherichia coli and Enterococcus in the experimental group was significantly lower than that in the control group ( F = 128.60, 224.99, all P < 0.05). The amount of Bifidobacteria and Lactobacilli in the experimental group was significantly higher than that in the control group ( F = 2 065.46, 948.23, both P < 0.05). After 10, 15, and 20 times of radiotherapy and after all radiotherapies, plasma D-lactic acid level in the experimental group was (9.34 ± 1.63) μg/L, (9.15 ± 1.36) μg/L, (8.68 ± 1.06) μg/L, and (8.05 ± 0.82) μg/L, respectively. After 10, 15, and 20 times of radiotherapy and after all radiotherapies, plasma diamine oxidase level in the experimental group was (86.34 ± 20.25) μg/L, (84.28 ± 17.45) μg/L, (80.40 ± 13.35) μg/L, and (76.85 ± 10.87) μg/L, respectively, and urinary excretion ratio of L to M in the experimental group was (1.84 ± 0.16), (1.55 ± 0.12), (1.26 ± 0.09), (0.98 ± 0.06), respectively, all of which were significantly lower than those in the control group ( F = 121.60, 31.73, 417.84, all P < 0.05). After 10, 15, and 20 times of radiotherapy and after all radiotherapies, CD4 + level in the experimental group was (39.80 ± 4.90)%, (40.92 ± 5.30)%, (42.52 ± 6.14)%, (43.83 ± 6.55)%, respectively, CD4 +/CD8 + was (1.52 ± 0.25), (1.63 ± 0.22), (1.71 ± 0.39), (1.83 ± 0.22), respectively, all of which were significantly higher than those in the control group ( F = 58.69, 31.07, all P < 0.05). Conclusion:Probiotics can improve the status of intestinal flora and intestinal barrier function in patients with cervical cancer after radiotherapy, and simultaneously improve the cellular immune function of patients.

Objective: To investigate the quantitative relationship between liver fat content and bone mineral density (BMD) in middle-aged and elderly people. Methods: Totally 184 middle-aged and elderly community residents were recruited from March to June 2016, including 68 males and 116 females. MRI mDIXON-Quant and quantitative CT (QCT) examinations were performed to determine the content of liver fat and L1-L3 vertebral BMD. The subjects were divided into four groups according to the quartiles of liver fat content, and the baseline characteristics and other variables of different groups were were identified by using one-way analysis of Variance. The relationship between liver fat content and lumbar vertebral BMD was assessed with Spearman correlation and partial correlation analysis. Result: Subjects with higher hepatic fat content had lower spine BMD and higher body mass index (BMI), waist circumference. Liver fat content was negatively correlated with BMD (r=-0.203, P=0.003). After age and body weight were controlled, the negative correlation between liver fat content and BMD was still significant (r=-0.291, P<0.001), in males (r=-0.283, P=0.021) and in females (r=-0.210, P=0.025). Conclusion Liver fat content is negatively correlated with lumbar vertebral BMD in middle-aged and elderly people.