A single phantom to mimic 1H MR spectra of different tissues

Object To design and build a single phantom, encompassing various elementary tubes, that mimics the 1H magnetic resonance (MR) spectra of liver, prostate, muscle and brain. Materials and Methods High-resolution NMR tubes were filled with water and the metabolite of interest, at a concentration of 50 mM, or with dairy cream or oil. The tubes (5 mm outer diameter) were placed into a plastic support, the ensemble was positioned in the center of a cuboid container filled with water. Simulations of the magnetic field inhomogeneity arising from the susceptibility variations in the current phantom were also performed. MR localized spectroscopy was performed on a 1.5 T clinical scanner. Results MR spectra of voxels positioned in four different locations of the phantom closely mimicked the resonance peaks of liver, prostate, muscle and brain in vivo MR spectra. In particular, for the muscle spectrum, the intramyocellular lipid (IMCL) and extramyocellular lipid (EMCL) resonances were obtained using dairy cream and oil, respectively. Simulations of the magnetic field inhomogeneity in the phantom showed that in the case of an NMR tube length five times greater than the thickness of the volume of interest, it is not necessary to fill the container with water. However, to ensure a good reception level and shim settings, the NMR tubes were immersed in water. Conclusions A single phantom of new design, that is easily built and highly reconfigurable, is here presented, to mimic the in vivo MR spectra of liver, prostate, muscle, brain and other models as needed.