Fundamentals of MRI measurements for gel dosimetry

Abstract

In radiotherapy gel dosimetry a humanoid phantom is irradiated according to the planned treatment of a patient. This results in a three-dimensional dose distribution. In order to read-out the gel dosimeter phantom, magnetic resonance imaging (MRI) is often used. Due to specific disturbances both the spatial and the dose reliability can be compromised. It is essential that the measurement sequence is optimized and that possible imaging artifacts are compensated in such a way that the proposed spatial and dose accuracy are met. In this review, several sources of disturbances are treated and compensation strategies are proposed. A code of good practice for the read-out technique is proposed. Finally, a tool for quality control of the imaging sequence is presented.