Integrated positron emission tomography (PET)/magnetic resonance (MR) imaging is gradually being used to
improve the rate of cancer lesion detection in the medical field. To enhance the quality of PET/MR images,
attenuation correction (AC) techniques are used by applying MR pulse sequences of the controlled aliasing in
parallel imaging results in higher acceleration (CAIPI; MR ACDixon-Caipi) and the generation autocalibrating
partially parallel acquisition (GRAPPA; MR ACDixon-Grappa), based on the T1-weighted two-point Dixon pulse
sequence. In addition, quality control using a Jaszczak phantom filled with water and radioisotopes is frequently
performed when scanning the patient. When acquiring MR-based AC PET images in the phantom
study, artifacts are caused by high permittivity in water, and there is a limitation in the acquisition of uniform
image quality. Therefore, the purpose of this study was to compare the image quality using phantom fluids with
lower permittivity than water (sodium chloride (NaCl) NaCl+nickel sulfate (NiSO4)) according to MR ACDixon-
Caipi and MR ACDixon-Grappa pulse sequences using various quantitative analysis parameters: percent of non-uniformity
(PNU), percent contrast recovery (PCR), signal to noise ratio (SNR), and coefficient of variation
(COV). The results indicated that the image quality with NaCl+NiSO4 fluid based on the results was 1.2-, 1.6-,
1.4-, and 1.1 times superior to that of NaCl fluid, respectively. In conclusion, NaCl+NiSO4 fluid is suitable as a
phantom fluid material in PET/MR images.