PurposeTo investigate the physical characteristics of the lumbar bone marrow fat content by analyzing the correlation of the lumbar bone marrow fat content with age, gender, body mass index (BMI) and waist circumference. It may be helpful to deepen the understanding the occurrence regularity of osteoporosis. Materials and Methods A total of 144 subjects were recruited including both healthy volunteers and the patients with chronic low back pain. The height, weight and waist circumference were measured, and the body mass index was calculated. All the subjects took spectroscopy sequence at the third lumber vertebra with single-voxel point resolved spectroscopy (PRESS) method. Lipid (1.3 ppm) to water (4.67 ppm) ratio (LWR) and lipid fractions (FF%) were measured. LWR and FF% of L3 were compared among the patients with different gender, age, BMI and waist circumference. The correlation of LWR and FF% of L3 and age were analyzed.Results The LWR and FF% of L3 showed no signiifcant difference between the male and female (t=-0.267 and-0.993,P>0.05). There was statistical difference of LWR and FF% among the different age groups (F=3.723 and 5.478,P<0.05). LWR and FF% of female in 61-70 year-old group showed signiifcant higher than that in 20-30, 31-40, 41-50 and 51-60 year-old group (P<0.05). FF% of L3 in 20-30 year-old female group showed signiifcant lower than that in >70 year-old group (P<0.05). LWR of L3 for both male and female in 60-70 year-old group also showed signiifcant higher than that in 20-30, 31-40, 41-50 and 51-60 year-old group (P<0.05). FF% for both male and female in 20-30 year-old group showed signiifcant lower than that in 31-40, 41-50, 51-60, 61-70 and>70 year-old group (P<0.05). FF% of 61-70 year-old group was signiifcant different from that in 31-40, 41-50, 51-60 year-old group (P<0.05). The LWR and FF% of L3 showed no signiifcant difference between the different BMI groups and waist circumference groups (P>0.05). Age was positive correlated with FF% of L3 (r=0.321,P<0.05).Conclusion The lumbar bone marrow fat content is correlated with age, but is not correlated with gender, BMI and waist circumference.

Objective To investigate the correlation between the changes of fat and microcirculation in vertebral marrow and the intervertebral disc degeneration. Methods This was a cross-sectional cohort study. Based on the inclusion and exclusion criteria, all 82 patients were recruited, while 246 lumbar intervertebral disc (L2/3-L4/5) were studied. Each disc was assessed by using Pfirrmann grades. The chemical shift imaging (CSI) was performed to calculate the signal intensity ratio (SIR) of the corresponding upper and under vertebral marrow. And intravoxel incoherent motion (IVIM) imaging was performed to obtain the IVIM parameters of slow apparent diffusion coefficient (Dslow), fast apparent diffusion coefficient (Dfast) and perfusion fraction (f). At the same time, b values of 0, 600 s/mm2 were used to obtain the ADC value of each disc. The ADC values of disc, the SIR values and IVIM parameters of the upper and under vertebral marrow between the different segments and different Pfirrmann grading groups were compared using one-way ANOVA or non-parametric test. The correlation of the Pfirrmann grading and ADC value of disc with the parameters of the vertebral marrow were analyzed, respectively. Results Only the f value of the upper and under vertebral marrow showed significant difference between the different segments groups of L2/3 to L4/5 discs (F=5.351 and 8.482, both P<0.05). The ADC values of discs, the SIR value of the upper vertebral marrow and the Dslow value of the under vertebral marrow had significant difference between the different Pfirrmann grading groups (all P<0.05). The Pfirrmann grading was negatively correlated with the disc ADC values (r=-0.651, P<0.01), and was mildly and positively correlated with the SIR values of the upper and under vertebral marrow (r=0.238 and 0.266, both P<0.01). The disc ADC values had a slightly negative correlation with the SIR value of the upper and under vertebral marrow(r=-0.230 and-0.247, both P<0.01). Conclusions The changes of the SIR value and all IVIM parameters of the vertebral bone marrow were not very obvious with the increasing of the grading of the intervertebral disc degeneration, which may be not an effective supplement for the grading of intervertebral disc degeneration.

Objective To investigate the correlation between the changes of fat and microcirculation in vertebral marrow and the intervertebral disc degeneration. Methods This was a cross-sectional cohort study. Based on the inclusion and exclusion criteria, all 82 patients were recruited, while 246 lumbar intervertebral disc (L2/3-L4/5) were studied. Each disc was assessed by using Pfirrmann grades. The chemical shift imaging (CSI) was performed to calculate the signal intensity ratio (SIR) of the corresponding upper and under vertebral marrow. And intravoxel incoherent motion (IVIM) imaging was performed to obtain the IVIM parameters of slow apparent diffusion coefficient (Dslow), fast apparent diffusion coefficient (Dfast) and perfusion fraction (f). At the same time, b values of 0, 600 s/mm2 were used to obtain the ADC value of each disc. The ADC values of disc, the SIR values and IVIM parameters of the upper and under vertebral marrow between the different segments and different Pfirrmann grading groups were compared using one-way ANOVA or non-parametric test. The correlation of the Pfirrmann grading and ADC value of disc with the parameters of the vertebral marrow were analyzed, respectively. Results Only the f value of the upper and under vertebral marrow showed significant difference between the different segments groups of L2/3 to L4/5 discs (F=5.351 and 8.482, both P<0.05). The ADC values of discs, the SIR value of the upper vertebral marrow and the Dslow value of the under vertebral marrow had significant difference between the different Pfirrmann grading groups (all P<0.05). The Pfirrmann grading was negatively correlated with the disc ADC values (r=-0.651, P<0.01), and was mildly and positively correlated with the SIR values of the upper and under vertebral marrow (r=0.238 and 0.266, both P<0.01). The disc ADC values had a slightly negative correlation with the SIR value of the upper and under vertebral marrow(r=-0.230 and-0.247, both P<0.01). Conclusions The changes of the SIR value and all IVIM parameters of the vertebral bone marrow were not very obvious with the increasing of the grading of the intervertebral disc degeneration, which may be not an effective supplement for the grading of intervertebral disc degeneration.