Protocol optimization for MRI studies in radiation oncology: I. Phantoms

Area of Science:

• Medical Physics
• Radiotherapy
• Quantitative Imaging

Background:

• Magnetic Resonance Imaging (MRI) is increasingly vital in radiation oncology for tasks like tumor delineation and response assessment.
• Quantitative MRI (qMRI) offers predictive biomarkers, but its implementation faces bias due to vendor-dependent sequences and analysis methods.
• Inconsistencies in imaging parameters and post-processing across institutions lead to significant variability in qMRI measurements.

Purpose of the Study:

• To address bias and uncertainty in quantitative MRI (qMRI) for radiotherapy.
• To introduce and evaluate in-house-built phantoms for optimizing and quality assuring MRI sequences, protocols, and post-processing methods.
• To enhance the reliability and robustness of MRI-based imaging biomarkers in radiation oncology.

Main Methods:

• Development and utilization of in-house-built phantoms for MRI sequence and protocol optimization.
• Quality assurance (QA) of MRI sequences, protocols, and post-processing techniques using specialized phantoms.
• Focus on harmonizing protocols and addressing bias in quantitative parametric MRI maps.

Main Results:

• In-house phantoms demonstrate utility in optimizing MRI sequences and protocols for radiotherapy applications.
• The developed methods aid in safeguarding the reliability and robustness of quantitative MRI measurements.
• Objective measures of uncertainty in quantitative parametric MRI maps can be provided.

Conclusions:

• In-house phantoms are essential tools for the optimization and quality assurance of MRI protocols in radiation oncology.
• Standardization and rigorous QA are critical for reducing bias and variability in qMRI biomarkers.
• Adapting QA approaches is necessary with the rise of advanced reconstruction techniques like compressed sensing.