MAGPHAN® MR Distortion Phantoms (ADNI) 051 & 121
Magphan® Quantitative Imaging Phantom - Models 051 & 121
The Magphan® Quantitative Imaging Phantom was developed with physicist Richard Mallozzi, Ph.D., to provide detailed mapping of image distortion in MRI images. The phantom contains an array of precisely positioned polycarbonate spheres. Comparing known and scanned sphere positions allows for a highly accurate distortion map to be created.
The Alzheimer's Disease Neuroimaging Initiative (ADNI) study selected the Magphan® EMR051 to monitor the MR distortion to control their study which involves critical volume measurements. The Magphan® Quantitative Imaging Phantoms continue to be widely used in neuroimaging studies where distortion monitoring is critical in fields such as autism and Alzheimer's research.
With the increasing use of MR scanners for radiation oncology planning and guidance concerns about distortion effects and their impact on treatment planning and delivery accuracy. Several white papers by Dr. Rich Mallozzi outline the sources of MR distortion and residual distortion after MR distortion corrections.The Magphan® Quantitative Imaging Phantom provides the ability to quantify the effects of distortion on these critical processes.
The Magphan® Quantitative Imaging Phantom is available in two models. The original phantom ( EMR051 ) in a 20cm housing with 165 polycarbonate spheres and an 18cm model ( EMR121) designed to fit inside smaller head coils. The EMR121 model contains 131 spheres.
The spheres are filled with copper sulfate and water solutions and are mounted on a series of polycarbonate plates and posts to maintain their fixed positions inside the phantom.
The original EMR051 phantom includes:
- one 6 cm diameter sphere,
- four 3 cm diameter spheres,
- two 1.5 cm diameter spheres
- one hundred and fifty-eight 1 cm spheres.
The EMR121 model includes:
- one 6 cm diameter sphere,
- three 1.5 cm diameter spheres
- one hundred and twenty-seven 1 cm spheres.
The differing solutions also provide means to measure contrast to noise ratios in the images.
The phantom housings are cast from a clear urethane material. The two halves of the sphere have a threaded connection allowing for internal access to the phantom if required.
Analysis Service for Magphan Model EMR051
In order to provide a standardized application of the original ADNI distortion measurement algorithm The Phantom Laboratory has partnered with Image Owl, Inc. to provide a convenient cost-effective online service to provide accurate analysis of MRI system spatial fidelity and to enable users to track results over time.
Image Owl’s MR Distortion Analysis Service provides web-based image processing, data analysis, and visualizations of distortion measurements. The database tools available offer a comprehensive picture of scanner performance over time, ideal for quality assurance programs and longitudinal studies
The smaller EMR121 Magphan model does not currently have an automated analysis available.