A quality control program for MR-guided focused ultrasound ablation therapy

Area of Science:

• Medical Physics
• Biomedical Engineering
• Radiology

Background:

• MR-guided focused ultrasound (FUS) ablation is a promising non-invasive treatment modality.
• Ensuring the accuracy and safety of FUS treatments is critical for patient outcomes.
• Standardized quality control (QC) protocols are essential for reliable FUS system performance.

Purpose of the Study:

• To develop and validate a comprehensive quality control program for MR-guided FUS ablation.
• To assess key parameters including beam positioning accuracy, power delivery, MR imaging quality, and system safety.
• To establish a QC workflow for implementation prior to clinical treatments.

Main Methods:

• Utilized Lucite cards to measure FUS beam positioning accuracy across 353 sonication points.
• Employed MR phase difference images and water proton chemical shift (WPCS) for temperature elevation calculations.
• Conducted 16 experiments with six phantoms to evaluate FUS power delivery reliability.
• Developed an automated computer program integrating FUS power delivery and MR image quality control.

Main Results:

• Average placement errors for FUS beams were minimal (-0.06 mm SI, -0.04 mm LR).
• WPCS temperature calibration yielded a coefficient of 0.011 ppm/degree C.
• Signal-to-noise ratio (SNR) and RF power were analyzed from phantom images.
• An automated QC process was successfully developed and integrated.

Conclusions:

• The proposed QC program effectively assesses critical parameters for MR-guided FUS ablation.
• The program ensures FUS beam positioning and power delivery accuracy, alongside MR imaging quality and system safety.
• Implementation of this QC program before each patient treatment is expected to enhance treatment safety and reliability.