Proton-density fat fraction and simultaneous R2* estimation as an MRI tool for assessment of osteoporosis

Abstract

Objective To investigate multi-echo chemical shift-encoded MRI-based mapping of proton density fat fraction (PDFF) and fat-corrected R2* in bone marrow as biomarkers for osteoporosis assessment. Methods Fifty-one patients (28 female; mean age 69.7 ± 9.0 years) underwent dual energy X-ray absorptiometry (DXA). On the basis of the t score, 173 valid vertebrae bodies were divided into three groups (healthy, osteopenic and osteoporotic). Three echo chemical shift-encoded MRI sequences were acquired at 3 T. PDFF and R2* with correction for multiple-peak fat (R2*MP) were measured for each vertebral body. Kruskal–Wallis test and post hoc analysis were performed to evaluate differences between groups. Further, the area under the curve (AUC) for each technique was calculated using logistic regression analysis. Results On the basis of DXA, 92 samples were normal (53 %), 47 osteopenic (27 %) and 34 osteoporotic (20 %). PDFF was increased in osteoporosis compared with healthy (P=0.007). R2*MP showed significant differences between normal and osteopenia (P=0.004), and between normal and osteoporosis (P<0.001). AUC to differentiate between normal and osteoporosis was 0.698 for R2*MP, 0.656 for PDFF and 0.74 for both combined. Conclusion PDFF and R2*MP are moderate biomarkers for osteoporosis. PDFF and R2*MP combination might improve the prediction in differentiating healthy subjects from those with osteoporosis.

Simultaneous Quantification of Bone Edema/Adiposity and Structure in Inflamed Bone Using Chemical Shift‐Encoded MRI in Spondyloarthritis

“…Our phantom experiments also indicated a positive association between R2* and BMD . A number of authors have previously explored the use of R2* or R2' as markers of osteoporosis, and these parameters have been found to parallel apparent density measured by dual‐energy X‐ray absorptiometry (DEXA) or quantitative CT (QCT) . However, our results indicate that R2* measurements also are influenced by PDFF and cannot be regarded as a pure marker of BMD when fat content varies as well.…”

“…Previous studies also support this suggestion. For example, Kühn et al showed that R2* measurements could discriminate normal and osteoporotic patients with reasonably high levels of sensitivity and specificity despite concomitant variations in fat content in osteoporotic individuals .…”

Assessment of whole spine vertebral bone marrow fat using chemical shift‐encoding based water‐fat MRI

“…In the context of osteoporosis, water-fat imaging-based vertebral bone marrow fat fraction was inversely correlated with BMD. [14][15][16] Furthermore, water-fat imaging based bone marrow fat fraction increased after chemotherapy and radiation therapy, thus detecting chemotherapy and radiation-induced bone marrow damage.…”

“…12,13 Vertebral bone marrow PDFF has been reported to be inversely correlated with BMD. [14][15][16] Furthermore, water-fat imaging has been successfully applied to detect chemotherapy and radiation-induced bone marrow damage.…”

Standardized Approach for ROI-Based Measurements of Proton Density Fat Fraction and R2* in the Liver

“…PDFF-based liver fat quantification enables the noninvasive assessment of hepatic steatosis, the hallmark histologic feature of nonalcoholic fatty liver disease, which is estimated to affect 20–30% of the Western population [4–9]. Further, these techniques allow the simultaneous estimation of fat- and noise-corrected liver iron content using R2* (1 / T2*) quantification from the same acquired CSE MRI data [10–12]. R2*-based liver iron quantification enables the noninvasive assessment of diseases that result in liver iron overload, including hereditary hemochromatosis, and blood transfusion–dependent conditions such as thalassemia, sickle cell disease, and bone marrow failure [13–18].…”