Polymer gel dosimetry utilizing a 2D (SE) and a 2D (HASTE) multiple echo sequences

Abstract

Two pulse sequences were used for the estimation of dosimetric characteristics of VIPET polymer gels. The first one, multi- echo spin echo (MESE) is the well-established method for T2 measurements. The other method is a new multi-echo single shot turbo spin echo pulse sequence, MEHASTE that reduces the acquisition time significantly. Both techniques showed a linear R2-dose response. With MESE sequence, the dose sensitivity was slightly enhanced as compared to MEHASTE. The linear portion of the R2-dose curve was restricted using the MEHASTE sequence. For doses above 7 Gy both methods fulfill the 2% ICRU criterion limit for dose resolution estimations (95% confidence level). Finally, for a time period of one month the temporal stability of R2-dose response was maintained stable utilizing both MESE and MEHASTE pulse sequences. MEHASTE serves as an excellent means for fast 3D polymer gel dosimetry.