Magnetic resonance elastography (MRE) is a noninvasive imaging technique used for the quantitative measurement of biomechanical properties. To improve the quantitative precision and spatial resolution, we are developing an external vibration device and pulse sequence with inversion algorithms for MRE systems. To compare the viscoelastic parameters between different elastography systeｚms and to optimize imaging parameters, we are developing tough and stable tissue-simulating viscoelastic phantoms.

We are developing an add-on positron emission tomography (PET) system that is composed of a magnetic resonance (MR) radio frequency (RF) coil integrated with depth-of-interaction (DOI) PET detectors, in collaboration with the National Institute of Radiological Sciences (NIRS-QST). In the proposed system, PET detectors are located extremely close to the MR RF coil. To reduce the electromagnetic interactions between the PET detectors and the MR RF coil, the PET detectors should be covered with conductive shield boxes. In this research, we validated that carbon fiber is effective as a shielding material in terms of the signal-to-noise ratio and eddy currents.