Predicting liver ablation volumes with real-time MRI thermometry.

Background & Aims: MRI guidance offers better lesion targeting for microwave ablation of liver lesions with higher soft-tissue contrast, as well as the possibility of real-time thermometry. This study aims to evaluate the correlation of real-time MR thermometry-predicted lesion volume with the ablation zone in postprocedural first-day images.

Methods: This single-center retrospective analysis evaluated prospectively included patients who underwent MRI-guided microwave ablation with real-time thermometry between December 2020 and July 2023.

Real-time multislice MR-thermometry of the prostate: Assessment of feasibility, accuracy and sources of biases in patients.

Purpose: The primary purpose of this study was to evaluate the accuracy of an MR-thermometry sequence for monitoring prostate temperature. The secondary purposes were to analyze clinical and technical factors that may affect accuracy and testing the method in a realistic setting, with MR-guided Laser ablation on an ex vivo muscle sample.

Materials And Methods: An ex vivo muscle sample was subjected to Laser ablation while using a two-dimensional multislice segmented echo planar imaging sequence for MR thermometry.

Evaluation of a deformable image registration algorithm for image-guided thermal ablation of liver tumors on clinically acquired MR-temperature maps.

Background: Quantitative real-time MRI-based temperature mapping techniques are hampered by abdominal motion. Intrascan motion can be reduced by rapid acquisition sequences such as 2D echo planar imaging (EPI), and inter-scan organ displacement can be compensated by image processing such as optical flow (OF) algorithms. However, motion field estimation can be seriously affected by local variation of signal intensity on magnitude images inherent to tissue heating, potentially leading to erroneous temperature estimates.

Automatic volumetric temperature regulation during in vivo MRI-guided laser-induced thermotherapy (MRg-LITT) with multiple laser probes.

Background: Clinical Laser-Induced Thermotherapy (LITT) currently lacks precise control of tissue temperature increase during the procedure. This study presents a new method to automatically regulate the maximum temperature increase in vivo at different positions by adjusting LITT power delivered by multiple laser probes using real-time volumetric MR-thermometry.

Methods: The regulation algorithm was evaluated in vivo on a pig leg muscle.

Accuracy of 3D real-time MRI temperature mapping in gel phantoms during microwave heating.

Background: Interventional magnetic resonance imaging (MRI) can provide a comprehensive setting for microwave ablation of tumors with real-time monitoring of the energy delivery using MRI-based temperature mapping. The purpose of this study was to quantify the accuracy of three-dimensional (3D) real-time MRI temperature mapping during microwave heating in vitro by comparing MRI thermometry data to reference data measured by fiber-optical thermometry.

Methods: Nine phantom experiments were evaluated in agar-based gel phantoms using an in-room MR-conditional microwave system and MRI thermometry.