On-line correction and visualization of motion during MRI-controlled hyperthermia

Area of Science:

• Medical Physics
• Biomedical Engineering
• Radiology

Background:

• Tissue displacement during MRI-controlled hyperthermia leads to inaccurate temperature calculations.
• Motion artifacts and inter-image displacement compromise spatial temperature referencing.

Purpose of the Study:

• To develop and validate a method for correcting motion-related temperature errors in MRI-guided hyperthermia.
• To enhance the accuracy and reliability of temperature mapping during hyperthermia treatments.

Main Methods:

• Incorporation of cyclic navigator echoes into rapid gradient-echo MRI sequences for temperature mapping.
• On-line evaluation of navigator information to minimize motion artifacts using phase information.
• Quantitative displacement evaluation via navigator profile matching and novel processing for reference temperature map correction.

Main Results:

• Motion artifacts in echo-shifted gradient-echo images were significantly minimized.
• Accurate quantitative displacement evaluation enabled correction of temperature maps, preventing persistent errors.
• On-line visualization of displacement, temperature, and thermal dose facilitated physician intervention.

Conclusions:

• The developed method effectively corrects motion-induced temperature errors during MRI-guided hyperthermia.
• On-line navigator echo evaluation improves the accuracy of temperature mapping and treatment monitoring.
• This approach enhances patient safety and treatment efficacy in hyperthermia therapy.