The MR Distortion Analysis Service, developed by Image Owl in close cooperation with the designers of the  Magphan® Distortion Analysis phantom, is the complete and accurate system for measuring 2D and 3D MR spatial distortion.

With the growing impact of MR Imaging in radiotherapy planning and guidance the measurement of MR image distortion and quality has become an increasing concern for many involved in this expanding field.

Image Owl has a 10 year track record in the distortion analysis and reduction of 2D and 3D MR image acquisitions. During that period , Image Owl software has been instrumental in analyzing MR distortion in thousands of neuroimaging image sets and has provided automated distortion reduction services in hundreds of additional cases.


Image Owl’s involvement with MR distortion analysis began in 2002 with the development of the Magphan® ADNI phantom as a collaborative research project with General Electric's’ Global Research Center. The method was adopted and further advanced by the Alzheimer's disease neuroimaging initiative (ADNI) project to standardize high-precision distortion measurements for multi-center imaging studies

Image Owl created a convenient cloud-based service to analyze, store and trend data for researchers. Since its inception the service has been involved in eight long-term longitudinal studies with 3-14 sites per study. The service has analyzed thousands of imaging studies over that period, giving Image Owl deep insights into MR distortion in actual clinical settings.

In 2009, Image Owl started providing distortion reduction services for a select group of clients performing quantitative neuroimaging studies that required submillimeter spatial accuracy for brain structure volume measurements. Image Owl developed a novel and highly accurate system that has successfully reduced MR distortion to submillimeter levels on over 300 studies.

MR Distortion in RT

Manufacturers’ gradient distortion correction algorithms correct much of the distortion due to nonlinearity inherent in gradient coil fields. However, three significant sources of gradient distortion remain:

  • residual distortion from imprecise gradient calibration
  • distortion in the slice direction on 2D pulse sequences
  • distortion due to disturbances in the static magnetic field (Bo)

Together, these sources of distortion commonly leave 1-3 mm of gradient-induced distortion in scanners that are operating within manufacturers’ specifications. With RT planning approaching submillimeter requirements in many cases, this residual distortion can have profound effects on treatment accuracy.

Led by imaging and QA thought leaders including Dr. Richard Mallozzi, developer of the Magphan® Quantitative Imaging phantom, Image Owl is leading the way in providing insightful QA measurements for MR imaging in radiotherapy.

Dr. Mallozzi has prepared a series of white papers exploring the sources of MR distortion and why distortion persists even after manufacturer distortion reduction efforts. Please contact us to receive copies of these papers.

Image Owl MR Distortion Analysis Service

The MR Distortion Analysis Service measures MR spatial distortion using scans of the The Phantom Laboratory’s Magphan® Quantitative Imaging Phantom.

The actual and scanned locations of the 165 spheres enclosed in the phantom are compared to produce measurements and mapping of scanner distortion (up to 4th order).The service provides 2D and 3D plots of sphere position to aid in visualization and analysis of distortion.

In addition to spatial distortion the service also measures signal to noise ratios (SNR), scaling and non-linearity.

All the data is stored and trended making it perfect for establishing a MR QA program across different facilities. Tolerances can be established with automatic e-mail alerts sent when measurements fall out of specification.

The MR Distortion Analysis Service’s cloud-based architecture requires no installation, and software updates are completely automated. Your data is visible at all times on any web enabled device.

Analyzing your Magphan® images could not be easier. Simply upload your MR scan into the web page and the service uploads the images, automatically categorizes and analyzes them, stores the results, and prepares a complete report.