Bone marrow adipose tissue (BMAT) is a dynamic tissue which is associated with osteoporosis, bone metastasis, and primary bone tumors. The aim of this study is to determine region-specific... Show moreBone marrow adipose tissue (BMAT) is a dynamic tissue which is associated with osteoporosis, bone metastasis, and primary bone tumors. The aim of this study is to determine region-specific variations and age- and gender-specific differences in BMAT and BMAT composition in healthy subjects. In this cross-sectional study, we included 40 healthy subjects (26 male: mean age 49 years, range 22-75 years; 14 female: mean age 50 years, range 29-71) and determined the bone marrow signal fat fraction and bone marrow unsaturation in the spine (C3-L5), pelvis, femora, and tibiae using chemical shift encoding-based water-fat imaging (WFI) with multiple gradient echoes (mGRE). Regions of interest covered the individual vertebral bodies, pelvis and proximal epimetaphysis, diaphysis, and distal epimetaphysis of the femur and tibia. The spinal fat fraction increased from cervical to lumbar vertebral bodies (mean fat fraction ( +/- SD or (IQR): cervical spine 0.37 +/- 0.1; thoracic spine 0.41 +/- 0.08. lumbar spine 0.46 +/- 0.01; p < 0.001). The femoral fat fraction increased from proximal to distal (proximal 0.78 +/- 0.09; diaphysis 0.86 (0.15); distal 0.93 +/- 0.02; p < 0.001), while within the tibia the fat fraction decreased from proximal to distal (proximal 0.92 +/- 0.01; diaphysis 0.91 (0.02); distal 0.90 +/- 0.01; p < 0.001). In female subjects, age was associated with fat fraction in the spine, pelvis, and proximal femur (rho = 0.88 p < 0.001; rho = 0.87 p < 0.001; rho = 0.63 p = 0.02; rho = 0.74 p = 0.002, respectively), while in male subjects age was only associated with spinal fat fraction (rho = 0.40 p = 0.04). Fat fraction and unsaturation were negatively associated within the spine (r = -0.40 p = 0.01), while in the extremities fat fraction and unsaturation were positively associated (distal femur: r = 0.42 p = 0.01; proximal tibia: r = 0.47, p = 0.002; distal tibia: r = 0.35 p = 0.03), both independent of age and gender. In conclusion, we confirm the distinct, age- and gender-dependent, distribution of BMAT throughout the human skeleton and we show that, contradicting previous animal studies, bone marrow unsaturation in human subjects is highest within the axial skeleton compared to the appendicular skeleton. Furthermore, we show that BMAT unsaturation was negatively correlated with BMAT within the spine, while in the appendicular skeleton, BMAT and BMAT unsaturation were positively associated. Show less
Objectives This study aimed to determine the effect of bariatric surgery-induced weight loss on bone marrow adipose tissue (BMAT) and bone mineral density (BMD) in postmenopausal, nondiabetic women... Show moreObjectives This study aimed to determine the effect of bariatric surgery-induced weight loss on bone marrow adipose tissue (BMAT) and bone mineral density (BMD) in postmenopausal, nondiabetic women.Methods A total of 14 postmenopausal, nondiabetic women with obesity who were scheduled for laparoscopic Roux-en-Y gastric bypass surgery (RYGB) were included in this study. Vertebral bone marrow fat signal fraction was determined by quantitative chemical shift magnetic resonance imaging, and vertebral volumetric BMD (vBMD) was determined by quantitative computed tomography before surgery and 3 and 12 months after surgery. Data were analyzed by linear mixed model.Results Body weight [mean (SD)] decreased after surgery from 108 (13) kg at baseline to 89 (12) kg at 3 months and 74 (11) kg at 12 months (P < 0.001). BMAT decreased after surgery from 51% (8%) at baseline to 50% (8%) at 3 months and 46% (7%) at 12 months (P = 0.004). vBMD decreased after surgery from 101 (26) mg/cm(3) at baseline to 94 (28) mg/cm(3) at 3 months (P = 0.003) and 94 (28) mg/cm(3) at 12 months (P = 0.035). Changes in BMAT and vBMD were not correlated (rho = -0.10 and P = 0.75). Calcium and vitamin D concentrations did not change after surgery.Conclusions RYGB decreases both BMAT (after 12 months) and vBMD (both after 3 months and 12 months) in postmenopausal, nondiabetic women. Changes in BMAT and vBMD were not correlated. These findings suggest that BMAT does not contribute to bone loss following RYGB. Show less
Dussen, L. van; Cox, T.M.; Hendriks, E.J.; Morris, E.; Akkerman, E.M.; Maas, M.; ... ; Hollak, C.E.M. 2012
PURPOSE: To develop a semiquantitative magnetic resonance (MR) imaging bone marrow burden (BMB) score with inclusion of both axial and peripheral bone marrow in Gaucher disease as an alternative to... Show morePURPOSE: To develop a semiquantitative magnetic resonance (MR) imaging bone marrow burden (BMB) score with inclusion of both axial and peripheral bone marrow in Gaucher disease as an alternative to MR imaging with the Dixon quantitative chemical shift imaging (QCSI) technique.MATERIALS AND METHODS: Two experienced musculoskeletal radiologists with no experience in evaluating Gaucher disease blindly analyzed MR images of lumbar spines and femora. Interobserver and intraobserver variability were tested. In addition, the BMB score was determined as a parameter to evaluate bone marrow response to enzyme supplementation therapy. Finally, the BMB score was compared with fat fraction measurements obtained with Dixon QCSI. Differences between groups were analyzed by using the nonparametric Mann-Whitney test. A P value of less than .05 was considered to represent significance. Correlation was calculated by using two-tailed nonparametric rank correlation (Spearman ρ).RESULTS: In 30 patients (mean age, 39.3 years; age range, 12–71 years) the mean fat fraction was 0.20 (range, 0.08–0.40). The BMB score range was 3–13 points. A significant correlation was found between the two observers when using BMB (ρ = 0.91, P < .001). The intraobserver variation showed a significant correlation (ρ = 0.99, P < .001). There was a significant correlation between BMB and QCSI (ρ = −0.78, P < .001). Although BMB was less sensitive than Dixon QCSI, it showed enough sensitivity to allow detection of bone marrow response to enzyme supplementation therapy.CONCLUSION: BMB is a reproducible semiquantitative scoring system that is easy to use. It combines MR imaging of both axial and peripheral bone marrow and shows a significant correlation with QCSI. Show less
