Related Experiment Video
Updated: Aug 5, 2026
10:05
In vivo 19F MRI for Cell Tracking
Published on: November 25, 2013
Correcting for rf inhomogeneities in multiecho pulse sequence MRI dosimetry
1Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada.
Medical Physics
|October 1, 1995
Summary
This study introduces a new MRI technique to accurately measure radiation dose distributions in phantoms. The echo quotient method improves accuracy for transverse relaxation rate (R2) measurements, making MRI dosimetry a potentially clinical tool.
Area of Science:
- Medical Physics
- Magnetic Resonance Imaging
- Radiation Dosimetry
Background:
- Growing interest in MRI for dose distribution measurement in specialized materials.
- Need for improved NMR relaxation rate measurements in large phantoms.
- Transverse relaxation rate (R2) is a sensitive dose measure, but accuracy is limited by MRI artifacts.
Purpose of the Study:
- To present a novel echo quotient technique for accurate R2 change (delta R2) measurement.
- To address inaccuracies caused by imperfect MRI tip angles in large phantoms.
- To validate the technique for measuring radiation dose distributions.
Main Methods:
- Development of a novel echo quotient technique.
- Application to measure dynamically wedged photon beam dose distribution.
- Comparison with existing MRI methods, film, and ion chamber data.
Main Results:
- The echo quotient technique allows accurate delta R2 measurement in regions with imperfect tip angles.
- Demonstrated improved accuracy compared to other methods for dose distribution measurement.
- MRI data agreed with film and ion chamber data within 2.5% in the region of interest.
Conclusions:
- The novel echo quotient technique enhances the accuracy of MRI-based R2 measurements.
- This method shows potential for clinical application in MRI dosimetry.
- Accurate delta R2 MRI dosimetry can be a valuable tool for radiation therapy.
