MR Thermometry

Abstract

Noninvasive and minimally invasive thermal therapy of benign and malignant diseases benefit from near-real-time magnetic resonance (MR) image guidance because of MRI’s unique ability to construct maps of in vivo body temperature. This chapter reviews the intrinsic MR parameters that display a temperature sensitivity: the proton resonance frequency (PRF), the diffusion coefficient, T 1 and T 2 relaxation times, magnetization transfer, and the proton density. The principles of temperature measurements with these parameters are reviewed and their usefulness for monitoring in vivo procedures is discussed. The excellent linearity and temperature dependence of the PRF and its near independence with regard to tissue type have made PRF-based phase mapping methods the preferred choice for many in vivo applications. Accelerated MRI techniques for real-time monitoring with the PRF method are discussed. Special attention is paid to acquisition and reconstruction methods for reducing temperature measurement artifacts introduced by tissue motion, which is often unavoidable during in vivo applications.KeywordsMagnetization TransferTemperature MonitoringMagnetic Resonance ElastographyThermal TherapyPhase DriftThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.