Marrow Fat Fraction Research Articles

Changes in Vertebral Marrow Fat Fraction Using 3D Fat Analysis & Calculation Technique Imaging Sequence in Aromatase Inhibitor-Treated Breast Cancer Women.

Aromatase inhibitor (AI) is a cornerstone drug for postmenopausal women with estrogen receptor-positive early-stage breast cancer. Fat-bone interactions within the bone marrow milieu are growing areas of scientific interest. Although AI treatment could lead to deterioration of the skeleton, the association between AI medication and subsequent marrow adiposity remains elusive. A total of 40 postmenopausal, early-staged, and hormone receptor-positive breast cancer patients who underwent treatment with adjuvant AIs and 40 matched controls were included. Marrow proton density fat fraction (PDFF) at the L1−L4 vertebral bodies using 3D Fat Analysis & Calculation Technique imaging (FACT) sequence at 3.0T, bone mineral density (BMD) by dual-energy X-ray absorptiometry, and serum bone turnover biomarkers were determined at baseline and at 6 and 12 months. We found that, in comparison to baseline, an increase of type I collagen cross-linked telopeptide was detected at 12 months (P <0.05). From baseline to 12 months, the PDFF measured using FACT was greatly increased. At 12 months, the median percent change of PDFF (4.9% vs. 0.9%, P <0.05) was significantly different between the AI treatments and controls. The same trend was observed for the marrow PDFF at 6 months relative to the respective values at baseline. Although BMD values were significantly reduced after 12 months in AI-treated women, changes in BMD vs. baseline condition were not significantly different between the AI-treated and control groups [Δ BMD −1.6% to −1.8% vs. −0.3% to −0.6%, respectively, P > 0.05]. In the AI-treated group, Δ PDFF was associated with Δ BMD at the lumbar spine (r = −0.585, P < 0.001), but not in the controls. Taken together, over a 12-month period, spinal marrow fat content assessed with FACT sequence significantly increased in postmenopausal women with hormone-receptor-positive breast cancer receiving AI treatment.

Effects of Total Flavonoids of Epimedium on Bone Marrow Adipose Tissue in Ovariectomized Rats.

Bone marrow adipose tissue has brown fat characteristics. Several studies have demonstrated that total flavonoids of Epimedium (TFE) could prevent bone loss and reduce the white adiposity in bone marrow induced by ovariectomy (OVX) in rats. However, the effects of TFE on marrow brown fat in OVX rats remain unclear. In this word, we addressed this question expected to provide a new target for preventing and treating osteoporosis. Thirty-six 3-month-old female Sprague-Dawley rats were equally divided into Sham controls, OVX controls, and OVX treated with TFE. Chemical shift coding magnetic resonance was performed to detect marrow fat fraction at the left femur at baseline, 6 and 12 weeks post-OVX. Bone mineral density at the lumbar spine and femur was measured by dual-energy x-ray absorptiometry. Serum bone biomarkers by ELISA, trabecular bone microarchitecture at the proximal tibia by micro-CT, quantitative parameters of marrow adipocyte by hematoxylin, and eosin staining were evaluated. The marrow adipocyte gene and protein expressions profile were determined by real-time quantitative PCR and immunostaining in whole tibiae. We found that TFE treatment could decrease bone turnover rate and improved bone mineral density and trabecular microarchitecture in OVX rats. OVX resulted in marrow adipogenesis as evidenced by increased marrow fat fraction, larger marrow adipocyte size, increased adipocyte number and percentage of adipocyte area, marrow white adipocyte gene, and protein expression, including PPARγ2 and FABP4. These pathological changes induced by estrogen deficiency were restored by TFE treatment. TFE also increased brown adipocyte expressions of the transcription factor Ucp1 and Prdm16 in whole tibiae. There was no detectible protein expression of brown adipocyte markers in the proximal tibia. Taken together, TFE regulation of bone marrow adiposity in OVX rats is mediated, at least in part, via maintaining the reciprocity of white and brown adipose tissue.

The contributions of cartilage endplate composition and vertebral bone marrow fat to intervertebral disc degeneration in patients with chronic low back pain

PurposeThe composition of the subchondral bone marrow and cartilage endplate (CEP) could affect intervertebral disc health by influencing vertebral perfusion and nutrient diffusion. However, the relative contributions of these factors to disc degeneration in patients with chronic low back pain (cLBP) have not been quantified. The goal of this study was to use compositional biomarkers derived from quantitative MRI to establish how CEP composition (surrogate for permeability) and vertebral bone marrow fat fraction (BMFF, surrogate for perfusion) relate to disc degeneration.MethodsMRI data from 60 patients with cLBP were included in this prospective observational study (28 female, 32 male; age = 40.0 ± 11.9 years, 19–65 [mean ± SD, min–max]). Ultra-short echo-time MRI was used to calculate CEP T2* relaxation times (reflecting biochemical composition), water-fat MRI was used to calculate vertebral BMFF, and T1ρ MRI was used to calculate T1ρ relaxation times in the nucleus pulposus (NP T1ρ, reflecting proteoglycan content and degenerative grade). Univariate linear regression was used to assess the independent effects of CEP T2* and vertebral BMFF on NP T1ρ. Mixed effects multivariable linear regression accounting for age, sex, and BMI was used to assess the combined relationship between variables.ResultsCEP T2* and vertebral BMFF were independently associated with NP T1ρ (p = 0.003 and 0.0001, respectively). After adjusting for age, sex, and BMI, NP T1ρ remained significantly associated with CEP T2* (p = 0.0001) but not vertebral BMFF (p = 0.43).ConclusionPoor CEP composition plays a significant role in disc degeneration severity and can affect disc health both with and without deficits in vertebral perfusion.

Assessment of Osteoporosis in Lumbar Spine: In Vivo Quantitative MR Imaging of Collagen Bound Water in Trabecular Bone.

AimBone collagen matrix makes a crucial contribution to the mechanical properties of bone by imparting tensile strength and elasticity. The collagen content of bone is accessible via quantification of collagen bound water (CBW) indirectly. We prospectively study the performance of the CBW proton density (CBWPD) measured by a 3D short repetition time adiabatic inversion recovery prepared ultrashort echo time (STAIR-UTE) magnetic resonance imaging (MRI) sequence in the diagnosis of osteoporosis in human lumbar spine.MethodsA total of 189 participants with a mean age of 56 (ranged from 50 to 86) years old were underwent MRI, quantitative computed tomography (QCT), and dual-energy X-ray absorptiometry (DXA) in lumbar spine. Major fracture risk was also evaluated for all participants using Fracture Risk Assessment Tool (FRAX). Lumbar CBWPD, bone marrow fat fraction (BMFF), bone mineral density (BMD) and T score values were calculated in three vertebrae (L2–L4) for each subject. Both the CBWPD and BMFF were correlated with BMD, T score, and FRAX score for comparison. The abilities of the CBWPD and BMFF to discriminate between three different cohorts, which included normal subjects, patients with osteopenia, and patients with osteoporosis, were also evaluated and compared using receiver operator characteristic (ROC) analysis.ResultsThe CBWPD showed strong correlation with standard BMD (R2 = 0.75, P < 0.001) and T score (R2 = 0.59, P < 0.001), as well as a moderate correlation with FRAX score (R2 = 0.48, P < 0.001). High area under the curve (AUC) values (≥ 0.84 using QCT as reference; ≥ 0.76 using DXA as reference) obtained from ROC analysis demonstrated that the CBWPD was capable of well differentiating between the three different subject cohorts. Moreover, the CBWPD had better correlations with BMD, T score, and FRAX score than BMFF, and also performed better in cohort discrimination.ConclusionThe STAIR-UTE-measured CBWPD is a promising biomarker in the assessment of bone quality and fracture risk.

Development of a novel method to measure bone marrow fat fraction in older women using high-resolution peripheral quantitative computed tomography

SummaryBone marrow adipose tissue (BMAT) has been implicated in a number of conditions associated with bone deterioration and osteoporosis. Several studies have found an inverse relationship between BMAT and bone mineral density (BMD), and higher levels of BMAT in those with prevalent fracture. Magnetic resonance imaging (MRI) is the gold standard for measuring BMAT, but its use is limited by high costs and low availability. We hypothesized that BMAT could also be accurately quantified using high-resolution peripheral quantitative computed tomography (HR-pQCT).MethodsIn the present study, a novel method to quantify the tibia bone marrow fat fraction, defined by MRI, using HR-pQCT was developed. In total, 38 postmenopausal women (mean [standard deviation] age 75.9 [3.1] years) were included and measured at the same site at the distal (n = 38) and ultradistal (n = 18) tibia using both MRI and HR-pQCT. To adjust for partial volume effects, the HR-pQCT images underwent 0 to 10 layers of voxel peeling to remove voxels adjacent to the bone. Linear regression equations were then tested for different degrees of voxel peeling, using the MRI-derived fat fractions as the dependent variable and the HR-pQCT-derived radiodensity as the independent variables.ResultsThe most optimal HR-pQCT derived model, which applied a minimum of 4 layers of peeled voxel and with more than 1% remaining marrow volume, was able to explain 76% of the variation in the ultradistal tibia bone marrow fat fraction, measured with MRI (p < 0.001).ConclusionThe novel HR-pQCT method, developed to estimate BMAT, was able to explain a substantial part of the variation in the bone marrow fat fraction and can be used in future studies investigating the role of BMAT in osteoporosis and fracture prediction.

Fully automated radiomic screening pipeline for osteoporosis and abnormal bone density with a deep learning-based segmentation using a short lumbar mDixon sequence.

Although lumbar bone marrow fat fraction (BMFF) has been demonstrated to be predictive of osteoporosis, its utility is limited by the requirement of manual segmentation. Additionally, quantitative features beyond simple BMFF average remain to be explored. In this study, we developed a fully automated radiomic pipeline using deep learning-based segmentation to detect osteoporosis and abnormal bone density (ABD) using a <20 s modified Dixon (mDixon) sequence. In total, 222 subjects underwent quantitative computed tomography (QCT) and lower back magnetic resonance imaging (MRI). Bone mineral density (BMD) were extracted from L1-L3 using QCT as the reference standard; 206 subjects (48.8±14.9 years old, 140 females) were included in the final analysis, and were divided temporally into the training/validation set (142/64 subjects). A deep-learning network was developed to perform automated segmentation. Radiomic models were built using the same training set to predict ABD and osteoporosis using the mDixon maps. The performance was evaluated using the temporal validation set comprised of 64 subjects, along with the automated segmentation. Additional 25 subjects (56.1±8.8 years, 14 females) from another site and a different scanner vendor was included as independent validation to evaluate the performance of the pipeline. The automated segmentation achieved an outstanding mean dice coefficient of 0.912±0.062 compared to manual in the temporal validation. Task-based evaluation was performed in the temporal validation set, for predicting ABD and osteoporosis, the area under the curve, sensitivity, specificity, and accuracy were 0.925/0.899, 0.923/0.667, 0.789/0.873, 0.844/0.844, respectively. These values were comparable to that of manual segmentation. External validation (cross-vendor) was also performed; the area under the curve, sensitivity, specificity, and accuracy were 0.688/0.913, 0.786/0.857, 0.545/0.944, 0.680/0.920 for ABD and osteoporosis prediction, respectively. Our work is the first attempt using radiomics to predict osteoporosis with BMFF map, and the deep-learning based segmentation will further facilitate the clinical utility of the pipeline as a screening tool for early detection of ABD.

Systematic review and meta-analysis: the value of MRI chemical-shift imaging in the evaluation of bone quality in patients with osteoporosis.

Osteoporosis is a systemic skeletal disease with no obvious symptoms in its early stages. The decreases in bone density and bone mass are associated with the deterioration of bony microstructure in the body, due to a variety of reasons. The current assessment criteria for osteoporosis are still not perfect. MRI chemical-shift imaging shows potential to be a valuable technique in the bone quality assessment of osteoporotic patients. Randomized controlled studies on osteoporosis assessment were searched for in English-language databases, including PubMed, Web of Science, Embase, and The Cochrane Library. Inclusion criteria were: (I) literature focused on the assessment of osteoporosis by chemical displacement imaging; (II) studies evaluating the bone quality of osteoporosis; (III) studies with at least 15 samples; (IV) studies concerned with the evaluation of osteoporosis by chemical shift encoded magnetic resonance imaging (CSE-MRI); and (V) studies with outcome indexes for bone mineral density (BMD), body mass index (BMI), and bone marrow fat fraction (BMFF). The Jadad tool was used to evaluate the quality of the included studies, and the Review Manager v. 5.3 software was used to conduct the meta-analysis of the experimental data. A total of 7 suitable articles were selected. According to the results of the meta-analysis, for the osteoporosis group and normal group: BMD: MD =41.91 [95% confidence interval (CI): 40.15 to 43.66], Z=46.82 (P<0.00001); BMI: MD =-1.43 (95% CI: -2.02 to -0.84), Z=4.76 (P<0.00001); BMFF: MD =-18.34 (95% CI: -20.32 to -16.36), Z=18.15 (P<0.00001). MRI chemical-shift imaging can effectively measure BMD and bone mass, including in osteoporotic patients. However, the outcome indicators included in this study are not sufficient to assess the utility of MRI chemical shift imaging for evaluating bone mass in osteoporotic patients, and further expansion of the sample size and outcome indicators is needed.

Quantifying Bone Marrow Fat Fraction and Iron by MRI for Distinguishing Aplastic Anemia from Myelodysplastic Syndromes

ROIs were manually drawn at the level containing the largest section of the left posterior superior ilium (A, B, D, E). The zoomed version of the ROIs showed in the upper left corner. (A, D) FF value of AA and MDS is 86.98% and 25.84%, respectively. (B, E) Iron content from R2*image is 117.91 and 147.98/second. (C, F) Histologic sections images of AA and MDS. Compared with MDS group (F), the number of fat cells (black arrow) in the AA group (C) was increased by Zeng et al. (1754–1760) image

Q-Dixon and GRAPPATINI T2 Mapping Parameters: A Whole Spinal Assessment of the Relationship Between Osteoporosis and Intervertebral Disc Degeneration.

The relationship between osteoporosis and intervertebral disc (IVD) degeneration remains controversial. Novel quantitative Dixon (Q-Dixon) and GRAPPATINI T2 mapping techniques have shown potential for evaluating the biochemical components of the spine. To investigate the correlation of osteoporosis with IVD degeneration in postmenopausal women. Prospective. A total of 105 postmenopausal females (mean age, 65 years; mean body mass index, 26 kg/m2 ). 3 T; sagittal; 6-echo Q-Dixon, multiecho spin-echo GRAPPATINI T2 mapping, turbo spin echo (TSE) T1-weighted and TSE T2-weighted sequences. The subjects were divided into normal (N=47), osteopenia (N=28), and osteoporosis (N=30) groups according to quantitative computed tomography examination. The Pfirrmann grade of each IVD was obtained. Region of interest analysis was performed separately by two radiologists (X.L., with 10 years of experience, and S.C., with 20 years of experience) on a fat fraction map and T2 map to calculate the bone marrow fat fraction (BMFF) from the L1 to L5 vertebrae and the T2 values of each adjacent IVD separately. One-way analysis of variance, post-hoc comparisons, and Kruskal-Wallis H tests were performed to evaluate the differences in the magnetic resonance imaging parameters between the groups. The relationships between BMFF and the IVD features were analyzed using the Spearman correlation analysis and linear regression models. There were significant differences in BMFF among the three groups. The osteoporosis group had higher BMFF values (64.5 ± 5.9%). No significant correlation was found between BMFF and Pfirrmann grade (r=0.251, P=0.06). BMFF was significantly negatively correlated with the T2 of the adjacent IVD from L1 to L3 (r=-0.731; r=-0.637; r=-0.547), while significant weak correlations were found at the L4 to L5 levels (r=-0.337; r=-0.278). This study demonstrated that osteoporosis is associated with IVD degeneration. 2 TECHNICAL EFFICACY: Stage 4.

Quantification of bone marrow edema in rheumatoid arthritis by using high-speed T2-corrected multiecho acquisition of 1H magnetic resonance spectroscopy: a feasibility study.

To determine whether high-speed T2-corrected multiecho (HISTO) sequences can quantify bone marrow edema (BME) in the capitate bone in rheumatoid arthritis (RA), and whether the HISTO fat fraction (FF) reflects therapeutic effectiveness. In this prospective study, 25 RA patients (19 women; average age, 45.08 ± 13.48years) underwent 3.0-T MRI with HISTO at the baseline and after 4, 8, and 12weeks of treatment. Rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), platelet (PLT) count, and 28-joint Disease Activity Score using ESR (DAS28-ESR) were recorded on the day of each MRI examination by a rheumatologist blinded to the MRI findings. In addition, 21 healthy subjects (15 women; age, 49.17 ± 6.56years) underwent only the HISTO sequence at a single time point. HISTO FF values were significantly higher in the control group (74.5% ± 3.1%; range, 68.6-79.3%) than in the patient group (55.8% ± 17.7%; range, 15.6-79.0%) at the baseline (independent-samples t-test: t = 5.257, P = 0.000). The changes in HISTO FF and DAS28-ESR showed moderate negative correlations with each other at 4, 8, and 12weeks, and all of them were statistically significant (P < 0.05). As the HISTO FF increased, the DAS28-ESR decreased. The HISTO sequence can measure the bone marrow FF of the wrist joint bones in RA patients. The HISTO FF value increased as the DAS28-ESR decreased. The HISTO sequence may help quantify BME in RA and help monitor the effectiveness of RA treatment. Key Points •The HISTO sequence could measure the bone marrow FF of the wrist joint bones. •FF value increased as the DAS28-ESR decreased in RA patients. •The HISTO sequence can monitor the therapeutic effect of RA.

Quantifying Bone Marrow Fat Fraction and Iron by MRI for Distinguishing Aplastic Anemia from Myelodysplastic Syndromes.

BackgroundBone marrow of patients with aplastic anemia (AA) is different from that of patients with myelodysplastic syndrome (MDS) and is difficult to identify by blood examination. IDEAL‐IQ (iterative decomposition of water and fat with echo asymmetry and least‐squares estimation) imaging might be able to quantify fat fraction (FF) and iron content in bone tissues.PurposeTo determine if IDEAL‐IQ measurements of bone marrow FF and iron content can distinguish between patients with AA and MDS.Study TypeRetrospective.PopulationFifty‐seven patients with AA, 21 patients with MDS, and 24 healthy controls.Field Strength/Sequence3.0 T, IDEAL‐IQ sequence.AssessmentThree independent observers evaluated the IDEAL‐IQ images and measured FF and R2* in the left posterior superior iliac spine.Statistical TestsKruskal–Wallis test, linear correlations, and Bland–Altman analysis were used. A P‐value of <0.05 was considered statistically significant.ResultsThe FF in patients with AA (79.46% ± 15.00%) was significantly higher than that in patients with MDS (42.78% ± 30.09%) and control subjects (65.50% ± 14.73%). However, there was no significant difference in FF between control subjects and patients with MDS (P = 0.439). The R2* value of AA, MDS, and controls was 145.38 ± 53.33, (171.13 ± 100.89, and 135.99 ± 32.41/second, respectively, with no significant difference between the three groups (P = 0.553).Data ConclusionQuantitative IDEAL‐IQ magnetic resonance imaging may facilitate the diagnosis of AA and distinguish it from MDS.Level of Evidence3Technical Efficacy Stage2

Quantitative Bone Marrow MRI in Children with Acute Lymphoblastic Leukemia

The aim of this study was to evaluate, using MRI, the changes in bone marrow fat fraction (BMFF) of patients with acute lymphoblastic leukemia (ALL), in comparison with children without hematological disorders. Methods and Results: The cohort of the study subjects included 20 patients aged between 5 and 17 years (mean age of 11.2±3.6 years; 10 boys and 10 girls) with clinically and morphologically confirmed diagnosis of ALL All patients underwent MRI scanning in the acute phase of the disease before the start of specific therapy. Then, the study was repeated in 10 patients (mean age of 12.2±2.3 years; 8 boys and 2 girls) during treatment, according to the ALL-MB 2015 protocol for patients with primary ALL and according to the ALL-REZ-MB 2016 protocol for patients with relapsed ALL. The control group consisted of 24 healthy controls of the same age group (mean age of 12±2.8; 17 boys and 7 girls) with no prior hematologic diseases. MRI scanning was carried out using a Philips Achieva dStream 3T scanner with a 32-channel FlexCoverage abdominal receiving coil. The MRI protocol included images obtained with the mDIXON Quant technique in the coronal plane, completely covering the pelvic bones and lumbar spine. Fat fraction (FF) maps were generated automatically on the MRI console using the 7-peak fat model and were corrected for T2* effects. Regions of interest (ROI) measuring 150 mm2 were placed in the bodies of the left and right iliac bones (Ilium L, Ilium R) as well as in the L4 and L5 vertebral bodies, taking care to avoid blood vessels, cortical bones and areas that could potentially contain artifacts. In the group of healthy controls, BMFF value was 51%±11% in the bodies of the iliac bones and 32%±10% in the lumbar vertebrae. In the group of patients with the acute phase of the disease, BMFF was as low as 3.1%±2.6% in all the bone structures. In patients who had undergone chemotherapy, the mean BMFF increased up to 77%±7% in the iliac bones and up to 65%±13% in the vertebrae. Student's t-test for dependent samples revealed a statistically significant increase in the mean BMFF values in all the bone structures after chemotherapy (P&lt;0.01). After specific therapy, BMFF was also significantly higher than under normal conditions (P&lt;0.01). Conclusion: This study provides important diagnostic information for various phases of ALL treatment, especially in suspected cases of resistant or recurrent disease.

Assessment of bone marrow fat fractions in the mandibular condyle head using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method.

The prevalence of temporomandibular joint disorder (TMD) is gradually increasing, and magnetic resonance imaging (MRI) is becoming increasingly common as a modality used to diagnose TMD. Edema and osteonecrosis in the bone marrow of the mandibular condyle have been considered to be precursors of osteoarthritis, but these changes are not evaluated accurately and quantitatively on routine MRI. The iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method, as a cutting-edge MRI technique, can separate fat and water using three asymmetric echo times and the three-point Dixon method. The purpose of this study was to analyze the quantitative fat fraction (FF) in the mandibular condyle head using the IDEAL-IQ method. Seventy-nine people who underwent MRI using IDEAL-IQ were investigated and divided into 1) the control group, without TMD symptoms, and 2) the TMD group, with unilateral temporomandibular joint (TMJ) pain. In both groups, the FF of the condyle head in the TMJ was analyzed by two oral and maxillofacial radiologists. In the TMD group, 29 people underwent cone-beam computed tomography (CBCT) and the presence or absence of bony changes in the condylar head was evaluated. The FF measurements of the condyle head using IDEAL-IQ showed excellent inter-observer and intra-observer agreement. The average FF of the TMD group was significantly lower than that of the control group (p < 0.05). In the TMD group, the average FF values of joints with pain and joints with bony changes were significantly lower than those of joints without pain or bony changes, respectively (p < 0.05). The FF using IDEAL-IQ in the TMJ can be helpful for the quantitative diagnosis of TMD.

Measurement of vertebral endplate bone marrow lesion (Modic change) composition with water\u2013fat MRI and relationship to patient-reported outcome measures

PurposeVertebral endplate bone marrow lesions (“Modic changes”, MC) are associated with chronic low back pain (CLBP). Bone marrow composition in MC is poorly understood. The goals of this study were to: (1) measure bone marrow fat fraction (BMF) in CLBP patients with MC using water–fat MRI and (2) assess the relationship between BMF measurements and patient-reported clinical characteristics.MethodsIn this cross-sectional study, 42 CLBP patients (men, n = 21; age, 48 ± 12.4 years) and 18 asymptomatic controls (men, n = 10; 42.7 ± 12.8 years) underwent 3 T MRI between January 2016 and July 2018. Imaging consisted of T1- and T2-weighted sequences to evaluate MC and spoiled gradient-recalled echo sequence with asymmetric echoes and least-squares fitting to measure BMF. BMF was compared between vertebrae with and without MC using mixed effects models. The relationship between the BMF measurements and patient-reported disability scores was examined using regression.ResultsTwenty-seven subjects (26 CLBP, 1 control) had MC, and MC presence coincided with significantly altered BMF. In MC 1, BMF was lower than endplates without MC (absolute difference −22.3%; p < 0.001); in MC 2, BMF was higher (absolute difference 21.0%; p < 0.001). Absolute BMF differences between affected and unaffected marrow were larger in patients with greater disability (p = 0.029–0.032) and were not associated with pain (p = 0.49–0.83).ConclusionBMF is significantly altered in MC. Water–fat MRI enables BMF measurements that may eventually form the basis for quantitative assessments of MC severity and progression.

Olive oil effectively mitigates ovariectomy-induced marrow adiposity assessed by MR spectroscopy in estrogen-deficient rabbits.

Polyphenols in extra virgin olive oil (EVOO) have been found to reduce the expression of PPARγ2, inhibit adipocyte differentiation, and enhance the formation of osteoblasts from bone marrow stem cells. However, the underlying mechanisms of their action remain unknown. To determine the sequential effects of EVOO on marrow fat expansion induced by estrogen deprivation using 3.0-T proton magnetic resonance (MR) spectroscopy in an ovariectomy (OVX) rabbit model of postmenopausal bone loss over a six-month period. A total of 45 female New Zealand rabbits were equally divided into sham-operation, OVX controls, and OVX treated with EVOO for six months. Marrow fat fraction was measured by MR spectroscopy at baseline conditions, and three and six months postoperatively, respectively. Serum bone biomarkers, lumbar and femoral bone mineral density, microtomographic parameters, biomechanical properties, and quantitative parameters of marrow adipocytes were studied. OVX was associated with marrow adiposity in a time-dependent manner, accompanied with increased bone turnover and impaired bone mass and trabecular microarchitecture. In OVX rabbits, EVOO markedly alleviated trabecular bone loss and reduced the accumulation of lipid droplets including adipocyte size, density, and areas of fat deposits in the bone marrow. EVOO prevented such changes in terms of both marrow adiposity and bone remodeling. Early EVOO treatment may exert beneficial effects on bone by modulating marrow adiposity, which would support their protective effect against bone pathologies.

Use of Quantitative Vertebral Bone Marrow Fat Fraction to Assess Disease Activity and Chronicity in Patients with Ankylosing Spondylitis

ObjectiveWe quantitatively measured the fat fraction (FF) in the vertebrae of patients with ankylosing spondylitis (AS) using magnetic resonance imaging (MRI) and investigated the role of FF as an indicator of both active inflammation and chronicity.Materials and MethodsA total of 52 patients with AS who underwent spinal MRI were retrospectively evaluated. The FF values of the anterosuperior and anteroinferior corners of the bone marrow in the L1-S1 spine were assessed using the modified Dixon technique. AS activity was measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), AS Disease Activity Score (ASDAS), and serum inflammatory marker levels. AS disease chronicity was assessed by AS disease duration and the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Univariable and multivariable regression analyses were conducted to investigate the correlation between FF and other clinical characteristics.ResultsThe mean FF ± standard deviation of the total lumbar spine was 43.0% ± 11.3%. At univariable analysis, spinal FF showed significant negative correlation with BASDAI (β = −0.474, p = 0.002) and ASDAS with C-reactive protein (ASDAS-CRP; β = −0.478, p = 0.002) and a significant positive correlation with AS disease duration (β = 0.440, p = 0.001). After adjusting for patient age, sex, and total mSASSS score, spinal FF remained significantly negatively correlated with BASDAI (β = −0.543, p < 0.001), ASDAS-CRP (β = −0.568, p < 0.001), and ASDAS with erythrocyte sedimentation rate (β = −0.533, p = 0.001). Spinal FF was significantly lower in patients with very high disease activity (ASDAS-CRP > 3.5) than in those with only high disease activity (2.1 ≤ ASDAS-CRP ≤ 3.5) (p = 0.010).ConclusionSpinal FF may help assess both AS disease activity and chronicity.

Effect of Low-Intensity Vibration on Bone Strength, Microstructure, and Adiposity in Pre-Osteoporotic Postmenopausal Women: A Randomized Placebo-Controlled Trial

ABSTRACT There has been evidence that cyclical mechanical stimulation may be osteogenic, thus providing opportunities for nonpharmacological treatment of degenerative bone disease. Here, we applied this technology to a cohort of postmenopausal women with varying bone mineral density (BMD) T-scores at the total hip (−0.524 ± 0.843) and spine (−0.795 ± 1.03) to examine the response to intervention after 1 year of daily treatment with 10 minutes of vibration therapy in a randomized double-blinded trial. The device operates either in an active mode (30 Hz and 0.3 g) or placebo. Primary endpoints were changes in bone stiffness at the distal tibia and marrow adiposity of the vertebrae, based on 3 Tesla high-resolution MRI and spectroscopic imaging, respectively. Secondary outcome variables included distal tibial trabecular microstructural parameters and vertebral deformity determined by MRI, volumetric and areal bone densities derived using peripheral quantitative computed tomography (pQCT) of the tibia, and dual-energy X-ray absorptiometry (DXA)-based BMD of the hip and spine. Device adherence was 83% in the active group (n = 42) and 86% in the placebo group (n = 38) and did not differ between groups (p = .7). The mean 12-month changes in tibial stiffness in the treatment group and placebo group were +1.31 ± 6.05% and −2.55 ± 3.90%, respectively (group difference 3.86%, p = .0096). In the active group, marrow fat fraction significantly decreased after 12 months of intervention (p = .0003), whereas no significant change was observed in the placebo group (p = .7; group difference −1.59%, p = .029). Mean differences of the changes in trabecular bone volume fraction (p = .048) and erosion index (p = .044) were also significant, as was pQCT-derived trabecular volumetric BMD (vBMD; p = .016) at the tibia. The data are commensurate with the hypothesis that vibration therapy is protective against loss in mechanical strength and, further, that the intervention minimizes the shift from the osteoblastic to the adipocytic lineage of mesenchymal stem cells. © 2020 American Society for Bone and Mineral Research (ASBMR).

Quantitative magnetic resonance imaging for determining bone marrow fat fraction at 1.5T and 3.0T: a technique to noninvasively assess cellularity and potential malignancy of the bone marrow.

Pediatric bone marrow assessment by MRI is challenging and primarily experiential and qualitative, with a paucity of clinically useful quantitative imaging techniques. MRI fat fraction (MRI-FF) is a technique used to quantify the degree of fat in other organ systems. The purpose of this study was to assess whether MRI-FF accurately measures bone marrow composition. This two-part study included a validation phase, followed by an application phase. For the validation phase, the MRI-FF of piglet bones (6 long bones, 8 axial bones) was performed at 1.5tesla (T) and 3.0T, and correlated to the histological fat fraction (H-FF). We used Bland-Altman plots to compare MRI-FF at 1.5 teslaT and 3.0T. For the application phase, five children with malignant marrow disease were recruited along with seven age- and gender-matched control subjects. The MRI-FF in the children was correlated to the H-FF. Boxplots were used to compare the MRI-FF of patients and control subjects. For the validation animal study, the MRI-FF of piglet bones at both 1.5T and 3.0T demonstrated moderate positive correlation to H-FF (r=0.41 and 0.42, respectively). MRI-FF at 1.5T and 3.0T were in good agreement, on average 7.7% apart. For the application phase, we included 5 children (4 with leukemia, 1 rhabdomyosarcoma) with median age 7years, range (3-10years). All children had MRI-FF and H-FF below 10%. The MRI-FF in patients (3.8±1.2) was significantly lower than that of control subjects (46.1±12.3%) (P<0.01). MRI-FF is a valid technique to assess bone marrow fat fraction at both 1.5T and 3.0T. The MRI-FF in children with malignant marrow processes is significantly lower than in control subjects with normal marrow.

Automatic Vertebral Body Segmentation Based on Deep Learning of Dixon Images for Bone Marrow Fat Fraction Quantification.

Background: Bone marrow fat (BMF) fraction quantification in vertebral bodies is used as a novel imaging biomarker to assess and characterize chronic lower back pain. However, manual segmentation of vertebral bodies is time consuming and laborious.Purpose: (1) Develop a deep learning pipeline for segmentation of vertebral bodies using quantitative water-fat MRI. (2) Compare BMF measurements between manual and automatic segmentation methods to assess performance.Materials and Methods: In this retrospective study, MR images using a 3D spoiled gradient-recalled echo (SPGR) sequence with Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) reconstruction algorithm were obtained in 57 subjects (28 women, 29 men, mean age, 47.2 ± 12.6 years). An artificial network was trained for 100 epochs on a total of 165 lumbar vertebrae manually segmented from 31 subjects. Performance was assessed by analyzing the receiver operating characteristic curve, precision-recall, F1 scores, specificity, sensitivity, and similarity metrics. Bland-Altman analysis was used to assess performance of BMF fraction quantification using the predicted segmentations.Results: The deep learning segmentation method achieved an AUC of 0.92 (CI 95%: 0.9186, 0.9195) on a testing dataset (n = 24 subjects) on classification of pixels as vertebrae. A sensitivity of 0.99 and specificity of 0.80 were achieved for a testing dataset, and a mean Dice similarity coefficient of 0.849 ± 0.091. Comparing manual and automatic segmentations on fat fraction maps of lumbar vertebrae (n = 124 vertebral bodies) using Bland-Altman analysis resulted in a bias of only −0.605% (CI 95% = −0.847 to −0.363%) and agreement limits of −3.275% and +2.065%. Automatic segmentation was also feasible in 16 ± 1 s.Conclusion: Our results have demonstrated the feasibility of automated segmentation of vertebral bodies using deep learning models on water-fat MR (Dixon) images to define vertebral regions of interest with high specificity. These regions of interest can then be used to quantify BMF with comparable results as manual segmentation, providing a framework for completely automated investigation of vertebral changes in CLBP.

Marrow Fat Content and Composition in β-Thalassemia: A Study using 1 H-MRS.

β-thalassemia is a genetic disease that causes abnormal production of red blood cells (ineffective erythropoiesis, IE). IE is a condition known to change bone marrow composition. To evaluate the effect of IE on the marrow fat content and fat unsaturation levels in the proximal femur using 1 H-MRS. Prospective. Twenty-three subjects were included in this study, seven control and 16 β-thalassemia subjects. 3.0T; stimulated echo acquisition Mode (STEAM); magnetic resonance spectroscopy (MRS) sequence. Multiecho MRS scans were performed in four regions of the proximal left femur of each subject, that is, diaphysis, femoral neck, femoral head, and greater trochanter. The examined regions were grouped into red (diaphysis and femoral neck) and yellow marrow regions (femoral head and greater trochanter). The Jonckheere-Terpstra test was used to evaluate the impact of increasing disease severity on bone marrow fat fraction (BMFF), marrow conversion index, and fat unsaturation index (UI). Pairwise comparison analysis was performed when a significant trend (P < 0.05) was found. K-means clustering analysis was used to examine the clusters observed when BMFF in the red and yellow regions were studied (diaphysis against greater trochanter). BMFF showed a significant decreasing trend with increasing disease severity in both red (TJT = 109.00, z = -4.414, P < 0.05) and yellow marrow regions (TJT = 108.00, z = -4.438, P < 0.05). The opposite trend was observed in UI in both bone marrow regions (red marrow: TJT = 180.5, z = 3.515, P < 0.05; yellow marrow: TJT = 155.0, z = 2.282, P = 0.05). Three distinct forms of marrow adipogenesis were found when plotting BMFF diaphysis against BMFF greater trochanter: 1) normal (centroid: 80.4%, 66.6%), 2) partial disruption (centroid: 51.1%, 16.6%), and 3) total disruption (centroid: 2.6%, 1.6%). β-thalassemia is associated with decreased marrow fat, and increased marrow fat unsaturation level. 2 TECHNICAL EFFICACY STAGE: 3.