Real-time volumetric MR thermometry using 3D echo-shifted sequence under an open source reconstruction platform

Abstract

Purpose: The aim of this work is to implement real-time 3D MR thermometry for high intensity focused ultrasound (HIFU) monitoring.

Methods: Volumetric MR thermometry was implemented based on a 3D echo-shifted sequence with short TR to improve temperature sensitivity. The 3D acquisition was accelerated in two phase encoding directions with controlled aliasing in volumetric parallel imaging (CAIPIRINHA). Image reconstruction was run in an open source reconstruction platform (Gadgetron).

Results: Phantom experiments showed the proposed volumetric thermometry was comparable to the fiber optical thermometer. In-vivo animal experiments in rabbit thigh showed that the temperature error before and after 4× acceleration was less than 0.65 °C. Finally, real-time 3D thermometry with temporal resolution ~3 s and spatial resolution 2 × 2 × 5 mm³ (spatial coverage 192 × 192 × 80 mm³) was achieved with Gadgetron reconstruction.

Conclusion: Real-time temperature monitoring was achieved in-vivo by using parallel imaging accelerated 3D echo-shifted sequence with Gadgetron reconstruction.

Keywords: Gadgetron; MR temperature imaging; Parallel imaging.