Robust Magnetic Resonance Temperature Mapping for Real-Time Guidance of Interventional Therapies

Abstract

Minimally-invasive thermal therapies, such as focused ultrasound, laser, or RF ablation, are a viable alternative to more invasive surgical procedures. These interventional therapies can be used treat everything from cancer to hippocampal epilepsy but are currently hindered by a lack of spatially-resolved real-time temperature monitoring during treatment. Magnetic resonance imaging (MRI) temperature mapping techniques can provide this critical feedback. However, current methods are limited to specific use cases in water-based tissues such as brain or muscle. Many methods fail in more difficult treatment scenarios such as fatty breast tissues or near metallic needles and ablation probes. Additionally, progress on novel ablation techniques such as focused ultrasound is hindered by a lack of well-validated, accessible systems for proof of concept studies. In this work I have developed MR thermometry algorithms and an open-source MR-guided focused ultrasound system to address these needs. This includes novel temperature map reconstruction methods to perform online correction of temperature mapping errors in fatty tissues, pulse sequence development to recover image signal and temperature precision near metallic probes, and validation of a custom MR-guided focused ultrasound system for preclinical studies.