Medical Physics

Biography

Biography: Marianthi-Vasiliki Papoutsaki

Abstract

For quantitative MR quality control, an ideal phantom must provide reliable and reproducible multi-parameter measurements without any temperature dependence. Despite the fact that several phantoms have been presented in the literature, there is still a need for a phantom, which would provide reliable and reproducible values of temperature-dependent magnetic resonant (MR) parameters with values relevant to the corresponding physiological ranges with temperature control. In this study, a new polyvinylpyrrolidone (PVP) temperature-controlled phantom is presented for the quality control of quantitative T1, T2 and diffusion measurements. This phantom is cylindrical and contains 7 vials, one of distilled water and six of aqueous Polyvinylpyrolidone solutions. Its temperature control was achieved by filling it with ice-water. T1-weighted, T2-weighted and diffusion-weighted measurements were performed on a 1.5T MR scanner by using an Inversion Recovery technique, a multi-echo spin echo sequence and single shot echo planar imaging acquisition respectively three times in order to assess their short and long-term repeatability. For each measurement, the corresponding parameter maps were calculated and the T1, T2 and ADC values of each vial were estimated. The results indicate good short and long-term repeatability. The ADC estimates and the relation with the PVP concentrations were consistent with previously published results covering a range of physiologically relevant values. T1 and T2 values were comparable with the corresponding values of biological tissues and fluids respectively. As a conclusion, a PVP phantom at ice-water temperatures is suitable and reliable for multi-parametric quantitative MR quality control in a clinical setting.