Usefulness of fat-containing agents: an initial study on estimating fat content for magnetic resonance imaging

Abstract

To investigate the usefulness of commercially available fat-containing agents in magnetic resonance imaging (MRI) based on bone mineral measurement. MethodsThe proximal femurs obtained from 14 volunteers were analyzed by 0.3T MRI with a fat-containing nutrient solution (based on soybean oil, 10% and 20%), 100% soybean oil and saline as reference substances. Fat content was estimated based on the relationship between the intensities of the signals of the reference substances. Since this was an approximate value, it was set as the estimated fat fraction based on signal intensity (SIeFF, %). The SIeFF values of the femoral bone marrow, including the femoral head, neck, shaft, and trochanter area, were measured. Reference substances were set as close as possible to the outside of both proximal femurs. MRI data were compared in terms of bone mineral content (BMC) and bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) in the proximal femur. MRI and DXA data were obtained on the same day. ResultsAccording to Pearson's correlation coe cient, the SIeFF and total BMC and BMD data revealed strong and moderate inverse correlations in the femoral head (r < − 0.74) and other sites (r = − 0.66 to − 0.45), respectively. ConclusionCommercially available fat-containing agents may be useful in estimating the bone marrow fat content for bone mineral measurement by MRI. SIeFF and BMC and BMD showed a strong inverse correlation in the femoral head. Nevertheless, a more thorough study is warranted before this method can be used as an alternative to DXA.