MR pulse sequence selection for optimal display of acrylic polymer phantoms

Abstract

Purpose Acrylic phantoms are being increasingly used as an alternative to cadaveric and animal derived tissue samples in pre-clinical magnetic resonance (MR) imaging research studies. Such phantoms have been imaged using a variety of MR sequences but little effort has been devoted to determining the most appropriate MR pulse sequence. In order to address this question, a prospective comparative study was performed to determine which MR sequence optimally demonstrates acrylic polymer phantoms. Methods Nine MR imaging sequences were selected and used to image an acrylic phantom placed in a water bath. The mid-sagittal slice of each sequence was used to determine signal-to-noise (S/N) and contrast-to-noise (C/N) ratios. The signal intensity maximum gradient at the phantom/fluid interface was used as a measure of edge delineation. Results Of the nine sequences reviewed the T2 driven equilibrium pulse sequence (DRIVE), a 3D turbo spin echo (TSE) sequence, provided the highest S/N (72.88) and C/N (69.62) ratios, while the proton density (PD) TSE or intermediate T2 TSE sequences provided the best edge delineation (definition of the acrylic-fluid interface). Conclusion This study suggests that selection of MR pulse sequences when evaluating a submersed acrylic phantom is dependent on which information is most important to the researcher. If S/N and C/N are considered most important, of the nine MR sequences tested, the T2 DRIVE sequence may be best employed. If edge delineation is considered most important, then PD or intermediate T2 TSE sequences may be best employed.