Related Experiment Video
Updated: Nov 21, 2025
Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
Published on: December 18, 2016
Sensitivity analysis of different quality assurance methods for magnetic resonance imaging in radiotherapy
Mary Adjeiwaah1, Anders Garpebring1, Tufve Nyholm1
1Department of Radiation Sciences, Umeå University, Umeå, Sweden.
Background And Purpose:
There are currently no standard quality assurance (QA) methods for magnetic resonance imaging (MRI) in radiotherapy (RT). This work was aimed at evaluating the ability of two QA protocols to detect common events that affect quality of MR images under RT settings.
Materials And Methods:
The American College of Radiology (ACR) MRI QA phantom was repeatedly scanned using a flexible coil and action limits for key image quality parameters were derived. Using an exploratory survey, issues that reduce MR image quality were identified. The most commonly occurring events were introduced as provocations to produce MR images with degraded quality. From these images, detection sensitivities of the ACR MRI QA protocol and a commercial geometric accuracy phantom were determined.
Results:
Machine-specific action limits for key image quality parameters set at were comparable with the ACR acceptable values. For the geometric accuracy phantom, provocations from uncorrected gradient nonlinearity effects and a piece of metal in the bore of the scanner resulted in worst distortions of 22.2 mm and 3.4 mm, respectively. The ACR phantom was sensitive to uncorrected signal variations, electric interference and a piece of metal in the bore of the scanner but could not adequately detect individual coil element failures.
Conclusions:
The ACR MRI QA phantom combined with the large field-of-view commercial geometric accuracy phantom were generally sensitive in identifying some common MR image quality issues. The two protocols when combined may provide a tool to monitor the performance of MRI systems in the radiotherapy environment.
Insights
Standard quality assurance (QA) methods for magnetic resonance imaging (MRI) in radiotherapy (RT) are lacking. This study evaluated two QA protocols, finding they can detect common issues affecting MR image quality in RT settings.
Area of Science:
- Medical Imaging
- Radiotherapy Physics
- Quality Assurance
Background:
- Standardized quality assurance (QA) protocols for magnetic resonance imaging (MRI) in radiotherapy (RT) are currently unavailable.
- Ensuring high-quality MR images is critical for accurate RT planning and delivery.
- Existing QA methods may not adequately address the unique challenges of MRI in RT environments.
Purpose of the Study:
- To evaluate the efficacy of two distinct QA protocols in detecting common image quality degradations specific to MRI in RT.
- To assess the sensitivity of the American College of Radiology (ACR) MRI QA phantom and a commercial geometric accuracy phantom.
- To identify potential solutions for monitoring MRI system performance in RT.
Main Methods:
- The American College of Radiology (ACR) MRI QA phantom was utilized to establish machine-specific action limits for image quality parameters.
- An exploratory survey identified common issues affecting MR image quality.
- These identified issues were simulated as provocations to degrade MR image quality.
- The detection capabilities of the ACR phantom and a geometric accuracy phantom were assessed against these simulated degradations.
Main Results:
- Machine-specific action limits were established and found comparable to ACR acceptable values.
- The geometric accuracy phantom detected significant distortions (up to 22.2 mm) due to uncorrected gradient nonlinearity and metal artifacts (3.4 mm).
- The ACR phantom effectively identified signal variations, electrical interference, and metal artifacts but failed to detect individual coil element failures.
Conclusions:
- The combined use of the ACR MRI QA phantom and a large field-of-view geometric accuracy phantom demonstrated sensitivity in identifying several common MR image quality problems.
- These integrated QA protocols offer a potential tool for consistent performance monitoring of MRI systems within the radiotherapy setting.
- Further development may be needed to address all potential failure modes, such as individual coil element issues.
More Related Videos
Related Concept Videos
01:24Magnetic Resonance Imaging
01:14Imaging Studies I: CT and MRI
Description of the Procedures
Computed Tomography (CT) scan:
Computed Tomography (CT) scans use X-ray technology to generate detailed images of bones, organs, and tissues. During the scan, the patient lies on a moving table...
01:30Radiological Investigation II: MRI and Ventilation Perfusion Scan
Magnetic Resonance Imaging (MRI) and Ventilation Perfusion Scans are two radiological investigations that offer detailed diagnostic images of the body, particularly lung structures.
MRI
MRI uses magnetic fields and radiofrequency signals to distinguish between normal and abnormal tissues. This technology provides a more detailed diagnostic image than CT scans, enabling it to characterize pulmonary nodules, stage bronchogenic carcinoma, and evaluate inflammatory activity in...
01:27Imaging Studies IV: Magnetic Resonance Imaging
01:21Imaging Studies for Cardiovascular System IV: CMRI