Bone Marrow Fat Fraction Research Articles

MRI-Based Phenotyping for Osteosarcopenic Adiposity in Subjects from a Population-Based Cohort

Objective: Imaging biomarkers of bone, muscle, and fat by magnetic resonance imaging (MRI) may depict osteopenia, sarcopenia, and adiposity as the three different conditions of osteosarcopenic adiposity (OSA). Methods: Subjects from a prospective, population-based case–control study underwent a health assessment and 3 Tesla whole-body MRI scan. Imaging biomarkers of bone (bone marrow fat-fraction (BMFF)), skeletal muscle (skeletal muscle FF (SMFF)), and fat (total adipose tissue (TAT)) were determined. Participants were allocated to one phenotype according to the OSA complex. Results: Among 363 participants forming the study cohort, 81 (22.3%, 48.1% males, 62.4 ± 6.9 years) were allocated into the OSA subgroup. Participants with an OSA phenotype were significantly older compared to all remaining subjects and showed the highest grades of SMFF (all p < 0.005). Together with subjects from the osteopenic sarcopenia group, OSA subjects exhibited the highest amounts of BMFF and together with the three other adiposity-containing subgroups also exhibited the highest BMIs. The highest prevalence of an impaired glucose tolerance as well as significantly higher blood pressure, blood dyslipidemia, and hepatic steatosis was found in the OSA subgroup (all p < 0.005). Conclusions: MR biomarkers of bone, skeletal muscle and fat are feasible for body composition phenotyping and may allow for targeted risk stratification in suspected OSA syndrome.

Effect of adipose tissue deposition on insulin resistance in middle-aged and elderly women: Based on QCT and MRI mDIXON-Quant.

To explore the relationship between adipose tissue deposition and triglyceride-glucose (TyG) index, an indicator clinically used to assess insulin resistance (IR), in middle-aged and elderly women using quantitative computed tomography (QCT) and MRI mDIXON-Quant sequence. All participants underwent quantitative computed tomography (QCT) and MRI mDIXON-Quant examination and calculated the TyG index based on the fasting blood glucose and triacylglycerol. Bounded by the median TyG index, all participants were divided into low TyG group and high TyG group. Visceral fat mass (VFM) and subcutaneous fat mass (SFM) were measured on QCT images. Hepatic proton density fat fraction (H-PDFF), pancreatic proton density fat fraction (P-PDFF), and lumbar bone marrow fat fraction (L-BMFF) were measured on MRI mDIXON-Quant images. Adjusting for age and body mass index (BMI), TyG was moderately positively correlated with H-PDFF, and r/P was 0.416/<0.001, TyG index was weakly positively correlated with VFM and P-PDFF, and r/P were 0.385/<0.001 and 0.221/0.030. There was a difference of VFM, H-PDFF, and P-PDFF between low TyG group and high TyG group (P < 0.05). Adjusting for age and BMI, VFM, and H-PDFF were the risk factors of high TyG, and H-PDFF was the independent risk factor of high TyG. VFM and H-PDFF were the risk factors of IR, and H-PDFF was the independent risk factor. Early identification and active treatment of adipose tissue deposition, especially hepatic fat deposition, may reserve and delay the progression of IR and even metabolic syndrome.

Effects of exercise on bone marrow adipose tissue in children with overweight/obesity: role of liver fat.

Exercise reduces adiposity, but its influence on bone marrow fat fraction (BMFF) is unknown; nor is it known whether a reduction in liver fat content mediates this reduction. (i) To determine whether incorporating exercise into a lifestyle program reduces the lumbar spine (LS)-BMFF, and (ii), to investigate whether changes in liver fat mediate any such effect. Ancillary analysis of a two-arm, parallel, non-randomized clinical trial. Primary care centres in Vitoria-Gasteiz (Spain). A total of 116 children with overweight/obesity were assigned to a 22-week family-based lifestyle program (control group [n=57]) or the same program plus an exercise intervention (exercise group [n=59]. The compared interventions consisted of a family-based lifestyle program (two 90-minute sessions/month) and the same program plus supervised exercise (three 90-minute sessions/week). The primary outcome examined was the change in LS-BMFF between baseline and 22 weeks, as estimated by MRI. The effect of changes in hepatic fat on LS-BMFF were also recorded. Mean weight loss difference between groups was 1.4±0.5 kg favour of the exercise group. Only the children in the exercise group experienced a reduction in LS-BMFF (effect size [Cohen d] -0.42, CI: -0.86, -0.01). Importantly, 40.9% of the reductions in LS-BMFF were mediated by changes in percentage hepatic fat (indirect effect: β=-0.104, 95%CI=-0.213, -0.019). The impact of changes in hepatic fat on LS-BMFF was independent of weight loss. The addition of exercise to a family-based lifestyle program designed to reduce cardiometabolic risk improves bone health by reducing LS-BMFF in children with overweight or obesity. This beneficial effect on bone marrow appears to be mediated by reductions in liver fat.

Acid sphingomyelinase deficiency and Gaucher disease in adults: Similarities and differences in two macrophage storage disorders.

The lysosomal storage diseases chronic visceral acid sphingomyelinase deficiency (ASMD) and Gaucher disease type 1 (GD1) are both macrophage storage disorders with overlapping clinical manifestations. We compared cross-sectional data on visceral, hematological, and biochemical manifestations of untreated adult patients with chronic visceral ASMD (n = 19) and GD1 (n = 85). Spleen volume, liver volume, and bone marrow fat fraction did not significantly differ between the two disease groups (p >0.05 for all). Chitotriosidase activity was higher in GD1 (GD1: median 30 940 nmol/(mL.h), range 513-201 352, ASMD: median 1693 nmol/(mL.h), range 326-6620, p <0.001), whereas platelet levels were lower (GD1: median 102 109/L, range 16-726, ASMD: median 154 109/L, range 86-484, p <0.010), as were hemoglobin levels (GD1: median 7.8 mmol/L, range 5.0-10.4, ASMD: median 9.0 mmol/L, range 7.0-10.4, p <0.001). No bone complications were reported for ASMD, compared to 33% in GD1 (p <0.005). In ASMD pulmonary disease was more severe as evidenced by a median diffusion capacity of the lungs for carbon monoxide of 73% of predicted (range 26-104), compared to 85% (range 53-126) in GD1 (p = 0.029). In conclusion, bone complications, hematological abnormalities, chitotriosidase activity, and CCL18 levels were more prominent in GD1, while pulmonary manifestations were more common in AMSD. Different secondary pathophysiological processes surrounding sphingomyelin and glucosylceramide accumulation might explain these differences.

Comparison of the value of adipose tissues in abdomen and lumbar vertebra for predicting disease activity in Crohn's disease: A preliminary study based on CSE-MRI

BackgroundTo compare the value of adipose tissues in abdomen and lumbar vertebra for predicting Crohn's disease (CD) activity based on chemical shift encoded magnetic resonance imaging (CSE-MRI). Methods84 CD patients were divided into remission, mild, and moderate-severely groups based on CD activity index (CDAI). Differences in different adipose parameters [subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), mesenteric fat index (MFI), and bone marrow fat fraction (BMFF)] and blood inflammatory indicators among three groups, as well as the correlation of above parameters and CDAI were analyzed. The areas under the receiver-operating characteristic curves (AUCs) for the parameters selected by multivariate logistic regression analysis for predicting active CD were calculated. ResultsThere were no significant differences in VAT and MFI among three groups (both P > 0.05). The cross-sectional areas of SAT in moderate-severe group were significantly lower than those in remission group (P = 0.014). BMFF values of remission group were significantly higher than those in the mild and moderate-severe groups (both P < 0.001). BMFF was negatively correlated with CDAI (r = −0.595, P < 0.001). SAT exhibited no significant correlation with CDAI. Erythrocyte sedimentation rate (ESR) and BMFF were the independent predictors of CDAI. Both combined had a higher diagnostic efficacy for active CD with an AUC of 0.895. ConclusionsBMFF is the best marker for predicting CD activity in fat parameters of abdomen and lumbar vertebra based on CSE-MRI. The model based on BMFF and ESR has a high efficiency in predicting active CD. Trial registrationNo. 22 K164 (Registered 18-07-2022).

Comparison of the accuracy of commercial two-point and multi-echo Dixon MRI for quantification of fat in liver, paravertebral muscles, and vertebral bone marrow

PurposeExcess fat accumulation contributes significantly to metabolic dysfunction and diseases. This study aims to systematically compare the accuracy of commercially available Dixon techniques for quantification of fat fraction in liver, skeletal musculature, and vertebral bone marrow (BM) of healthy individuals, investigating biases and sex-specific influences. Method100 healthy White individuals (50 women) underwent abdominal MRI using two-point and multi-echo Dixon sequences. Fat fraction (FF), proton density fat fraction (PDFF) and T2* values were calculated for liver, paravertebral muscles (PVM) and vertebral BM (Th8–L5). Agreement and systematic deviations were assessed using linear correlation and Bland-Altman plots. ResultsHigh correlations between FF and PDFF were observed in liver (r = 0.98 for women; r = 0.96 for men), PVM (r = 0.92 for women; r = 0.93 for men) and BM (r = 0.97 for women; r = 0.95 for men). Relative deviations between FF and PDFF in liver (18.92 % for women; 13.32 % for men) and PVM (1.96 % for women; 11.62 % for men) were not significant. Relative deviations in BM were significant (38.13 % for women; 27.62 % for men). Bias correction using linear models reduced discrepancies. T2* times were significantly shorter in BM (8.72 ms for women; 7.26 ms for men) compared to PVM (13.45 ms for women; 13.62 ms for men) and liver (29.47 ms for women; 26.35 ms for men). ConclusionWhile no significant differences were observed for liver and PVM, systematic errors in BM FF estimation using two-point Dixon imaging were observed. These discrepancies – mainly resulting from organ-specific T2* times – have to be considered when applying two-point Dixon approaches for assessment of fat content. As suitable correction tools, linear models could provide added value in large-scale epidemiological cohort studies. Sex-specific differences in T2* should be considered.

A novel deep learning method for large-scale analysis of bone marrow adiposity using UK Biobank Dixon MRI data

BackgroundBone marrow adipose tissue (BMAT) represents > 10% fat mass in healthy humans and can be measured by magnetic resonance imaging (MRI) as the bone marrow fat fraction (BMFF). Human MRI studies have identified several diseases associated with BMFF but have been relatively small scale. Population-scale studies therefore have huge potential to reveal BMAT’s true clinical relevance. The UK Biobank (UKBB) is undertaking MRI of 100,000 participants, providing the ideal opportunity for such advances. ObjectiveTo establish deep learning for high-throughput multi-site BMFF analysis from UKBB MRI data. Materials and methodsWe studied males and females aged 60–69. Bone marrow (BM) segmentation was automated using a new lightweight attention-based 3D U-Net convolutional neural network that improved segmentation of small structures from large volumetric data. Using manual segmentations from 61–64 subjects, the models were trained to segment four BM regions of interest: the spine (thoracic and lumbar vertebrae), femoral head, total hip and femoral diaphysis. Models were tested using a further 10–12 datasets per region and validated using datasets from 729 UKBB participants. BMFF was then quantified and pathophysiological characteristics assessed, including site- and sex-dependent differences and the relationships with age, BMI, bone mineral density, peripheral adiposity, and osteoporosis. ResultsModel accuracy matched or exceeded that for conventional U-Nets, yielding Dice scores of 91.2% (spine), 94.5% (femoral head), 91.2% (total hip) and 86.6% (femoral diaphysis). One case of severe scoliosis prevented segmentation of the spine, while one case of Non-Hodgkin Lymphoma prevented segmentation of the spine, femoral head and total hip because of T2 signal depletion; however, successful segmentation was not disrupted by any other pathophysiological variables. The resulting BMFF measurements confirmed expected relationships between BMFF and age, sex and bone density, and identified new site- and sex-specific characteristics. ConclusionsWe have established a new deep learning method for accurate segmentation of small structures from large volumetric data, allowing high-throughput multi-site BMFF measurement in the UKBB. Our findings reveal new pathophysiological insights, highlighting the potential of BMFF as a novel clinical biomarker. Applying our method across the full UKBB cohort will help to reveal the impact of BMAT on human health and disease.

Quantitative bone marrow magnetic resonance imaging in children with lymphoblastic leukaemia

The aim of the study was to evaluate fat fraction (FF) changes in patients diagnosed with acute lymphoblastic leukaemia (ALL) in comparison with children without haematological disorders. All the patients or their legal representatives gave their informed consent to magnetic resonance imaging (MRI). The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology and was conducted in line with the Ethical Principles of the World Health Organization (the Declaration of Helsinki) for Medical Research Involving Human Subjects. The study included 33 healthy volunteers aged 13.4 ± 2.8 years (the control group) and 34 patients with acute phase ALL whose mean age was 12.2 ± 3.6 years (the group of interest). Imaging of the pelvic bones and lumbar vertebrae was performed on a Philips Achieva 3T scanner using the mDixon-quant sequence, with a subsequent construction of FF maps. The Mann–Whitney U-test was used to compare the FF data of the cases with each other and with the controls. Four regions of interest were selected, 100 mm2 each: in the bodies of the right and the left iliac bones as well as in the bodies of the L4 and L5 vertebras. For each group of subjects and each region of interest, mean FF was calculated. In the group of the patients with acute phase ALL, FF was the lowest: 3.53 ± 2.75% and 3,72 ± 3.09% in the bodies of the left and right iliac bones respectively, and 2.62 ± 1.86% and 2.47 ± 2.17% in the L4 and L5 vertebras respectively. In the control group, FF in the respective regions of interest was 51.3 ± 9.5%; 49.9 ± 11.0%; 31.3 ± 8.73% and 32.4 ± 10.3%. It is obvious that bone marrow FF in the patients with ALL differs significantly from the control group. Quantitative MRI can become a new method for the assessment of changes in the bone marrow of children with leukaemias.

Longitudinal MR-based proton-density fat fraction (PDFF) and T2* for the assessment of associations between bone marrow changes and myelotoxic chemotherapy

ObjectivesMR imaging-based proton density fat fraction (PDFF) and T2* imaging has shown to be useful for the evaluation of degenerative changes in the spine. Therefore, the aim of this study was to investigate the influence of myelotoxic chemotherapy on the PDFF and T2* of the thoracolumbar spine in comparison to changes in bone mineral density (BMD).MethodsIn this study, 19 patients were included who had received myelotoxic chemotherapy (MC) and had received a MR imaging scan of the thoracolumbar vertebrates before and after the MC. Every patient was matched for age, sex, and time between the MRI scans to two controls without MC. All patients underwent 3-T MR imaging including the thoracolumbar spine comprising chemical shift encoding-based water-fat imaging to extract PDFF and T2* maps. Moreover, trabecular BMD values were determined before and after chemotherapy. Longitudinal changes in PDFF and T2* were evaluated and compared to changes in BMD.ResultsAbsolute mean differences of PDFF values between scans before and after MC were at 8.7% (p = 0.01) and at −0.5% (p = 0.57) in the control group, resulting in significantly higher changes in PDFF in patients with MC (p = 0.008). BMD and T2* values neither showed significant changes in patients with nor in those without myelotoxic chemotherapy (p = 0.15 and p = 0.47). There was an inverse, yet non-significant correlation between changes in PDFF and BMD found in patients with myelotoxic chemotherapy (r = −0.41, p = 0.12).ConclusionTherefore, PDFF could be a useful non-invasive biomarker in order to detect changes in the bone marrow in patients receiving myelotoxic therapy.Clinical relevance statementUsing PDFF as a non-invasive biomarker for early bone marrow changes in oncologic patients undergoing myelotoxic treatment may help enable more targeted countermeasures at commencing states of bone marrow degradation and reduce risks of possible fragility fractures.Key PointsQuantifying changes in bone marrow fat fraction, as well as T2* caused by myelotoxic pharmaceuticals using proton density fat fraction, is feasible.Proton density fat fraction could potentially be established as a non-invasive biomarker for early bone marrow changes in oncologic patients undergoing myelotoxic treatment.

Association between IDEAL-IQ MRI fat fraction quantification and pelvic bone marrow reserve function in concurrent chemoradiotherapy for cervical cancer

ObjectiveTo analyze the association between iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantification sequence (IDEAL-IQ) magnetic resonance imaging (MRI) of bone marrow fat fraction and bone marrow reserve function during concurrent chemoradiotherapy for cervical cancer. MethodsThe study retrospectively analyzed twenty-six patients with stage IB1 to IVA cervical cancer treated between February 2020 and November 2020. All patients received concurrent chemoradiotherapy that included platinum alone or combined paclitaxel and platinum. Pelvic IDEAL-IQ MRI (plain and enhanced) was performed before and after treatment. Regions of interest, including the fifth lumbar vertebra, sacrum, ilium, ischium, and femoral neck, were manually delineated, and the bone marrow fat fraction was measured. Peripheral blood cell counts were recorded during treatment, and the relationship between the fat fraction values and changes in the blood cell counts was explored. ResultsIDEAL-IQ MRI bone marrow fat fraction was associated with platelet nadir and platelet decline during treatment. The average pelvic bone marrow fat fraction before chemoradiotherapy was moderately negatively correlated with platelet count nadir during concurrent chemoradiotherapy (r ​= ​−0.450, P ​= ​0.021). The change in average pelvic bone marrow fat fraction through chemoradiotherapy was moderately positively correlated with the degree of thrombocytopenia (r ​= ​0.399, P ​= ​0.044). ConclusionBone marrow fat content quantified by IDEAL-IQ was associated with platelet count nadir and the degree of thrombocytopenia in patients with cervical cancer undergoing concurrent chemoradiotherapy.

Liver Fat, Bone Marrow Adipose Tissue, and Bone Mineral Density in Children With Overweight.

Hepatic steatosis is associated with decreased bone mineral density (BMD). Bone marrow fat fraction (BMFF) could play a role in this relationship in children with obesity. The objectives of this work were (i) to examine the relationship between the lumbar spine (LS) BMFF and BMD, and (ii) to explore the mediating role of LS-BMFF on the relationship between percentage hepatic fat with LS-BMD in preadolescent children with overweight/obesity. Hepatic fat and LS-BMFF (magnetic resonance imaging) and areal LS-BMD (LS-aBMD, dual-energy x-ray absorptiometry) were measured in 106 children (aged 10.6 ± 1.1 years, 53.8% girls) with overweight/obesity. LS-BMFF was inversely associated with LS-aBMD (r = -0.313; P = .001) and directly related with percentage hepatic fat (r = 0.276; P = .005). LS-BMFF was significantly greater in children with than without hepatic steatosis (P = .003; Cohen's d: 0.61; 95% CI, -0.21 to 1.0), while no significant difference was seen between children with overweight and those with obesity (P = .604; Cohen's d: 0.16; 95% CI, -0.21-0.55). Mediating analysis indicated that LS-BMFF is an important mediator (50%) in the association of hepatic fat with lower LS-aBMD (indirect effect: β = -.076; 95% CI, -0.143 to -0.015). These findings suggest that hepatic steatosis, rather than overall excess adiposity, is associated with greater bone marrow adipose tissue in preadolescent children with overweight/obesity, which in turn, is related to lower BMD. Hepatic steatosis could be a potential biomarker of osteoporosis risk, and a therapeutic target for interventions that aim to reduce not only hepatic steatosis, but for those designed to improve bone health in such children.

Assessment of Osteoporosis at the Lumbar Spine Using Ultrashort Echo Time Magnetization Transfer (UTE-MT) MRI.

Bone collagen-matrix contributes to the mechanical properties of bone by imparting tensile strength and elasticity, which can be indirectly quantified by ultrashort echo time magnetization transfer ratio (UTE-MTR) to assess osteoporosis. To evaluate osteoporosis at the human lumbar spine using UTE-MTR. Prospective. One hundred forty-eight-volunteers (age-range, 50-85; females, N = 90), including 81-normal bone density, 35-osteopenic, and 32-osteoporotic subjects. Ten additional healthy volunteers were recruited to study the intrasession reproducibility of the UTE-MT. 3T/UTE-MT, short repetition-time adiabatic inversion recovery prepared UTE (STAIR-UTE), and iterative decomposition of water-and-fat with echo-asymmetry and least-squares estimation (IDEAL-IQ). Fracture risk was calculated using Fracture-Risk-Assessment-Tool (FRAX). Region-of-interests (ROIs) were delineated on the trabecular area in the maps of bone-mineral-density, UTE-MTR, collagen-bound water proton-fraction (CBWPF), and bone-marrow fat fraction (BMFF). Linear-regression and Bland-Altman analysis were performed to assess the reproducibility of UTE-MTR measurements in the different scans. UTE-MTR and BMFF were correlated with bone-mineral-density using Pearson's regression and with FRAX scores using nonlinear regression. The abilities of UTE-MTR, CBWPF, and BMFF to discriminate between the three patient subgroups were evaluated using receiver-operator-characteristic (ROC) analysis and area-under-the-curve (AUC). Decision-curve-analysis (DCA) and clinical-impact curves were used to evaluate the value of UTE-MTR in clinical diagnosis. The DeLong test was used to compare the ROC curves. P-value <0.05 was considered statistically significant. Excellent reproducibility was obtained for the UTE-MT measurements. UTE-MTR strongly correlated with bone-mineral-density (r = 0.76) and FRAX scores (r = -0.77). UTE-MTR exhibited higher AUCs (≥0.723) than BMFF, indicating its superior ability to distinguish between the three patient subgroups. The DCA and clinical-impact curves confirmed the diagnostic value of UTE-MTR. UTE-MTR and CBWPF showed similar performance in correlation with bone-mineral-density and cohort classification. UTE-MTR strongly correlates with bone-mineral-density and FRAX and shows great potential in distinguishing between normal, osteopenic, and osteoporotic subjects. 1 TECHNICAL EFFICACY: Stage 2.

Preliminary Study of Confounder-Corrected Fat Fraction and R2* Mapping of Bone Marrow in Children With Acute Leukemia.

The bone marrow (BM) evaluation of acute leukemia (AL) mainly depends on invasive BM puncture biopsy. Noninvasive and accurate MR examination technology has potential clinical application value in the BM evaluation of AL patients. Multi-gradient-echo (MGRE) has been found useful to evaluate changes in BM fat and iron content, but has not yet been applied in AL. To explore the diagnostic capability of BM infiltration of quantitative BM fat fraction (FF) and R2* values obtained from a 3D MGRE sequence in children with primary AL. Prospective. Sixty-two pediatric patients with untreated AL and 68 healthy volunteers. AL patients were divided into acute lymphoblastic leukemia (ALL) (n = 39) and acute myeloid leukemia (AML) (n = 23) groups. 3T, 3D chemical-shift-encoded multi-gradient-echo, T1WI, T2WI, T2_STIR. BM FF and R2* values were assessed by manually drawing regions of interest at the L3, L4, ilium, and 1 cm below the bilateral trochanter of the femur (upper femur). Independent sample t-tests, variance analysis, Spearman correlation. BM FF and R2* at L3, L4, ilium, and upper femur, FFtotal and R2*total were significantly lower in the AL than control group. BM FF did not significantly differ between ALL and AML groups (PL3 = 0.060, PL4 = 0.086, Pilium = 0.179, Pupper femur = 0.149, and Ptotle = 0.097, respectively). The R2* was significantly lower in ALL group than AML group for L3, L4, and R2*total . BM FF was moderately positively correlated with R2* in ALL group, and strongly positively correlated in AML group. Area under the receiver operating characteristic curves showed that BM FF had higher AUC in AL, ALL, and AML (all AUC = 1.000) than R2* (0.976, 0.996, and 0.941, respectively). MGRE-MRI mapping can be applied to measure BM FF and R2* values, and help evaluate BM infiltration and iron storage in children with AL. 1 Technical Efficacy: 2.

Quantification of spinal bone marrow fat fraction using three-material decomposition technique on dual-energy CT: A phantom study.

Two-material decomposition is insufficient to quantify the fat fraction of spinal bone marrow, which is comprised of a mixture of bone minerals, water, and yellow marrow (fat). To develop an accurate three-material decomposition-based bone marrow fat fraction ( ) quantification technique for dual-energy CT. Bone marrow edema phantoms containing trabecular bone minerals, water, and fat were constructed using fat fractions and bone mineral density values matching those expected in healthy and edematous bone, and scanned on a commercial dual-energy CT. Fat quantified by were compared to MRI-based fat fraction ( ) and conventional two-material-decomposition-based fat fraction ( ) to evaluate its accuracy and dependency on various bone mineral densities. demonstrated an excellent correlation with (r=0.97, R2 =0.96) in the phantom, significantly more accurate than FF2MD when confounding bone minerals are present (50mg/cm3 : r=1.02, R2 =0.95vs. r=0.65, R2 =0.79 (p<0.01); 100mg/cm3 : r=0.81, R2 =0.47vs. r=0.21, R2 =0.21 (p<0.05)). accurately quantified bone marrow fat fraction, when compared with , in the specially constructed bone marrow phantom.

Bone marrow cellularity assessment using magnetic resonance imaging in children with aplastic anemia

Aplastic anemia is a life-threatening condition characterized by the suppression of all hematopoietic lineages in the bone marrow. Empty intertrabecular spaces are replaced by adipose tissue. With modern MR techniques for assessing fat fraction, it has become possible to capture these changes. The fat fraction is estimated as the ratio of the signal intensity from fat to the sum of the fat and water signals. Aim of the study: to assess the diagnostic value of bone marrow fat fraction quantification in patients aged &lt; 18 years with aplastic anemia. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Healthcare of the Russian Federation. The study included 66 participants aged under 18 years. A control group consisted of 33 healthy subjects with a mean age of 13.03 ± 2.83 years. A group of interest included 33 children with a confirmed diagnosis of aplastic anemia, with a mean age of 12.31 ± 4.39 years. The study was carried out at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Healthcare of the Russian Federation; all scanning was performed on a Philips Achieva 3.0T MRI scanner using the mDixon-quant sequence in the iliac bones and lumbar vertebrae. Our results showed that bone marrow fat fraction was significantly higher in the aplastic anemia group than in the controls. In the patients with aplastic anemia, the mean fat fraction values in the iliac bones and in the L4, L5 vertebrae were 82.62 ± 10.92% and 73.52 ± 17.52%, respectively. In the control group, the mean fat fraction values for these sites were 51.04 ± 11.41% and 31.43 ± 10.61%, respectively. We found a significant difference in fat fraction values for the same sites between the groups (p &lt; 0.01). Bone marrow fat fraction quantification by MRI allows for the detection of decreased cellularity of the marrow in patients under 18 years of age with aplastic anemia compared to healthy children.

Quantitative MRI evaluation of bone marrow in sickle cell disease: relationship with haemolysis and clinical severity

To evaluate bone marrow fat fraction using the Dixon technique (FFDix) of magnetic resonance imaging (MRI) as a potential biomarker of haemolysis and clinical severity in the overall assessment and follow-up of sickle cell disease (SCD) patients. The present study was a cross-sectional study in which healthy individuals and SCD patients (matched for age, sex, and weight) were subjected to MRI of the lumbar spine and pelvis to quantify FFDix in the bone marrow using the Dixon technique. SCD severity was analysed by clinical and laboratory data, and an online calculator. A high degree of haemolysis was defined using the cut-off values haemoglobin (Hb) ≤10 g/dl, lactate dehydrogenase (LDH) ≥325 U/l, reticulocytes ≥3% and total bilirubin (TB) ≥1.2 mg/dl. Pearson's correlation, receiver operating characteristic (ROC) curve and binary logistic regression analysis were performed. Forty-eight SCD patients (26 homozygous: HbSS and 22 compound heterozygous: HbSC) and 48 healthy individuals participated in the study. FFDix was lower in SCD patients than in the control group, showing even lower values in the HbSS subtype and patients with a higher degree of haemolysis. HbSC patients with a higher degree of haemolysis using hydroxyurea (medium dosage 9.8 mg/kg/day) had lower FFDix. ROC curves and odds ratios for detecting patients with a higher degree of haemolysis at the different FFDix measurement sites demonstrated excellent performance: iliac bones (cut-off ≤16.75%, AUC=0.824, p<0.001), femoral heads (cut-off ≤46.7%, AUC=0.775, p=0.001), lumbar vertebrae (cut-off ≤7.8%, AUC=0.755, p=0.002). Decreased FFDix is indicative of higher degree of haemolysis and SCD severity with great potential as a non-invasive biomarker contributing to the overall assessment and follow-up of SCD patients.

Fat fraction quantification of bone marrow in the lumbar spine using the LiverLab assessment tool in healthy adult volunteers and patients with Gaucher disease.

Magnetic Resonance Imaging is used for evaluation of bone in Gaucher disease (GD), but a widely available quantitative scoring method remains elusive. The study purpose was to assess the reproducibility of the LiverLab tool for assessing bone marrow fat fraction (FF) and determine whether it could differentiate GD patients from healthy subjects. Ten healthy volunteers and 18 GD patients were prospectively recruited. FF was calculated at L3, L4 and L5. GD patient bone marrow burden (BMB) score assessed by one observer. Inter and intra-rater agreement assessed with Bland-Altman data plots. Differences in FF between healthy volunteers versus GD patients and between subjects treated versus not treated assessed using two-sample t-tests. In GD patients, the relationship between FF, BMB and glucosylsphingosine was determined using the Pearson's correlation coefficient. Healthy volunteer mean FF was 0.36, standard deviation (SD) 0.10 (range 0.20-0.57). Intra and inter-rater SD were both 0.02. GD patient mean FF was 0.40, SD 0.13 (range 0.09-0.57). No statistical difference was shown between healthy volunteers and GD patients (P=0.447) or between GD patients whether on enzyme replacement therapy or not (P=0.090). No significant correlation between mean FF and total BMB (r=-0.525, P=0.253) or between FF and glucosylsphingosine levels (r=0.287, P=0.248). Excellent reproducibility of LiverLab FF measurements across studies and observers is comparable to Dixon quantitative chemical shift imaging (QCSI). Lack of statistical difference between GD patients and controls may be explained by limited patient numbers, active treatment or mild disease severity in untreated patients.

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.