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Objective To validate a chemical shift-encoded MRI(CSE-MRI)water-fat imaging for quantifying vertebral marrow fat content using MRS as the reference standard.Methods MRS and CSE-MRI were performed to calculate proton density fat fraction(PDFF) in 83 subjects,including 41 normal bone mass,26 osteopenia and 16 osteoporosis.Eight participants were scanned three times with repositioning to assess the repeatability of CSE-MRI PDFF measurements.Agreements of intra-observer and inter-observer were evaluated by intraclass correlation coefficient(ICC).Linear regression,Bland-Altman 95% limit of agreement and Lin's concordance correlation coefficient were calculated.Results The repeatability for CSE-MRI PDFF measurements expressed as absolute precision error was 1.45%.PDFF was 62.1%±11.1% by MRS and 60.4%±10.1% by CSE-MRI in 83 subjects.There were significant differences in PDFF among the normal bone mass,osteopenia and osteoporosis groups after adjusting for age,years since menopause and body mass index (all P<0.001).The intra-and inter-rater reliability for duplicate measurements at CSE-MRI PDFF were more than 0.993.Pearson correlation coefficient was 0.979 and Lin's concordance correlation coefficient was 0.962.All data points calculated using the Bland-Altman method were within the limits of agreement.Inverse associations were observed between BMD (r=-0.560--0.710)and CSE-MRI-based PDFF,and between BMD (r=-0.539--0.706)and MRS-based PDFF in various groups.Conclusion CSE-MRI with multiple lipids peak model and T2?-correction is equally accurate in characterizing marrow fat content as MRS.
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PURPOSE: To investigate and compensate the effects of respiration-induced B0 variations on fat quantification of the bone marrow in the lumbar spine. MATERIALS AND METHODS: Multi-echo gradient echo images with navigator echoes were obtained from eight healthy volunteers at 3T clinical scanner. Using navigator echo data, respiration-induced B0 variations were measured and compensated. Fat fraction maps were estimated using T2*-IDEAL algorithm from the uncompensated and compensated images. For manually drawn bone marrow regions, the estimated B0 variations and the calculated fat fractions (before and after compensations) were analyzed. RESULTS: An increase of temporal B0 variations from inferior level to superior levels was observed for all subjects. After compensation using navigator echo data, the effects of the B0 variations were reduced in gradient echo images. The calculated fat fractions show significant differences (P < 0.05) in L1 and L3 between the uncompensated and the compensated. CONCLUSION: The results of this study raise the need for considering respiration-induced B0 variations for accurate fat quantification using gradient echo images in the lumbar spine. The use of navigator echo data can be an effective way for the reduction of the effects of respiratory motion on the quantification.
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Medula Óssea , Compensação e Reparação , Voluntários Saudáveis , Respiração , Coluna VertebralRESUMO
Objective To detect the changes in vertebral marrow fat fraction (MFF) using T2 *-corrected water-fat MRI and to analyze the relationships between MFF with bone biomarkers of non-dialysis chronic kidney disease (CKD).Methods 78 CKD patients were divided into five groups according to the eGFR and underwent water/fat MRI to obtain MFF.The reliability of MFF measurements by two radiologists was assessed with intra-class correlation coefficient (ICC).Serum calcium,phosphorus,alkaline phosphatase,osteocalcin,intact parathyroid hormone and 25(OH)D3 were determined.Results Mean CV for MFF measurements reproducibility was 2.37％.The inter-observer agreement for MFF was excellent (ICC=0.901).The ICC for each intra-observer agreement was excellent (ICC=0.959 and 0.948,respectively).There were statistical differences in MFF among five groups of CKD.Changes of MFF were earlier than those of serum calcium,phosphorus,parathyroid hormone,alkaline phosphatase and osteocalcin.MFF was positively correlated with serum phosphorus (r =3.011,P =0.003),parathyroid hormone (r=3.852,P＜0.001),and negatively associated with calcium (r=-2.767,P=0.017),25(OH)D3 (r=6.032,P＜0.001),eGFR (r=-5.104,P＜0.001),respectively.Multivariable regression analysis showed MFF was negatively correlated with 25(OH)D3(Sβ=-0.343)and eGFR(S(S=-0.284,P＜0.001).Conclusion CKD patients had higher marrow fat.T2 *-corrected water fat MRI could serve as a useful tool to quantify marrow fat content for CKD patients.
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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.
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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.
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Cancer has become the second largest life-threatening disease nowadays.Radiotherapy and chemotherapy are still important treatments for cancer.However, they tend to produce a lot of serious adverse effects including bone damage and bone marrow fat, etc.Based on recent research, the research progress on canonical Wnt pathway and its impact on stromal stem cells differentiation into osteoblasts and adipocytes are reviewed.Radiochemotherapy-induced bone damage and bone marrow fat is closely related to canonical Wnt pathway.In experimental assay and clinical application, Wnt pathway antagonists, such as Dickkopf-1 (DKK-1), sclerostin, and secreted frizzled-related protein 1 (sFRP-1) are used to relieve bone damage.Wnt pathway is expected to become a potential target for the therapy of bone damage and bone marrow fat induced by raidochemotherapy.
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PURPOSE: The purpose of this study was to determine whether there is a significant correlation between vertebral marrow fat fraction measured using Dixon quantitative chemical shift MRI (QCSI) and BMD on dual-energy X-ray absorptiometry (DXA). MATERIALS AND METHODS: This retrospective study included 68 healthy individuals [mean age, 50.7 years; range, 25-76; male/female (M/F) = 36/32] who underwent DXA of the L-spine and whole body MRI including QCSI of the L-spine and chemical shift MRI of the liver. The enrolled individuals were divided into subgroups according to sex and T-score [i.e., normal bone density (M/F=27/23) and osteopenia (M/F=9/9)]. Vertebral marrow (Dixon QCSI, TR/TE 10.2/4.8 ms) and hepatic fat fractions (chemical shift technique, TR/TE 110/4.9 and 2.2 ms) were calculated on MRI. We evaluated whether there were significant differences in age, body mass index (BMI), vertebral marrow fat fraction, or hepatic fat fraction among the subgroups. Whether or not the participant had reached menopause was also evaluated in females. The correlations among variables (i.e., age, BMI, vertebral marrow and hepatic fat fractions, BMD) were evaluated using Spearman's correlation method. RESULTS: There were no significant differences in age, BMI, or vertebral marrow and hepatic fat fractions between the two male subgroups (normal bone density vs. osteopenia). In female subjects, mean age in the osteopenic subgroup was greater than that in the normal subgroup (p=0.01). Presence of menopause was more common in the osteopenic subgroup [77.8% (7/9)] than the normal subgroup [26.1% (6/23), p<0.05]. The other variables showed no significant difference between female subgroups. The only significant correlation with marrow fat fraction after partial correlation analysis was that with age in the female subjects (r=0.43, p<0.05). CONCLUSION: The vertebral marrow fat fraction calculated using the Dixon QCSI does not precisely reflect the mild decrease in BMD for either sex.