Non-invasive NMR thermometry and temperature monitering using the proton resonance frequenccy method

Abstract

The proton resonance frequency (PRF) method for nuclear magnetic resonance (NMR) thermometry has emerged as a notable method for non-invasive temperature measurement. The PRF method has been investigated by a number of researchers. The ability to perform temperature measurements without direct contact between the probe and the sample is highly desirable for numerous medical operations, as well as various other non-medical applications. This research introduced NMR then-nometry as a new direction of research for the Magnetic Resonance Systems Laboratory (MRSL). The theory and principles of the PRF method are thoroughly investigated. The 2.OT MRI system is tested for phase and temporal stability and is determined whether it is capable of accurate NMR thermometry. Experiments demonstrated accurate temperature measurements within a gel phantom using the PRF method. The results show that temperature measurements using the PR.F method can be performed using the MRSL MRI system. This method is a valuable tool for future research involving temperature measurements such as monitoring of laser coagulation in tissues or microwave heating. A phase difference algorithm is also introduced as a tool to eliminate errors caused by phase wrapping. In addition, a script command was written for the MRI system providing the user with the ability to monitor temperature changes within the phantom.