Non-Invasive in vivo Loss Tangent Imaging: Thermal Sensitivity Estimation at the Larmor Frequency

Abstract

Magnetic resonance imaging (MRI) is a versatile tool widely used for diagnosing disease. It provides high resolution anatomical information of the human with excellent soft tissue contrast, obtained in a non-invasive manner, and can be used to guide treatments and surgeries through monitoring of temperature and visualization of tumors (1-5). More recent applications related to hyperthermic therapy include magnetic resonance-guided laser-induced thermal therapy (3) and MR-guided focused ultrasound surgery (2), which demonstrated the possibility for application of MRI as a valuable tool in managing the ablation region. Hyperthermic ablation is a widely used therapeutic tool for cardiac arrhythmias and cancers of the liver, lung, kidney, and bone (6-9). RF and microwave ablation utilize the thermal sensitivity differences between tumor and normal tissue, which are primarily determined by the electrical properties (i.e., permittivity and conductivity). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Received: March 11, 2016 Accepted: March 20, 2016