QUASAR™ MRID3D is a new, patent pending, cost-effective QA system for quantifying geometric distortion in 3D MR images. Analysis is performed on images for MRgRT and diagnostic imaging applications.
Unlike other distortion analysis products, which only sample a few imaging planes, the QUASAR™ MRID3D Geometric Distortion Analysis System analyzes the entire 3D volume in a single series acquisition.
The system uses a novel method based on 3D harmonic analysis of distortion by analyzing the Boundary Distortion Vector Field derived from the location of known control points on the surface of the phantom. 3D Laplace Partial Differential Equations are used to calculate the entire 3D Distortion Vector Field.
The hollow, acrylic phantom features integrated feet and handles for fast and easy setup in MRI scanners and includes image analysis software with a built-in 3D DICOM Viewer and Region of Interest (ROI) selector permitting user analysis of smaller custom volumes.
A submission to Medical Physics is available online:
The QUASAR™ MRID3D Geometric Distortion Analysis System results compare favourably to conventional grid phantoms, which have higher inherent susceptibility/sample distortion.
- Patent Pending
- Isocenter Detection
- Fiducial Markers
- Reference Markers
- Fast Processing
- Feature-rich Graphics
- Built-in 3D DICOM Viewer
- Axial Plots
- Automated Analysis
- Trend Analysis
- Export Results
- Detailed Reports
- Multi-App Phantom
- Large 3D Volume
- Hollow Phantom
- Waterless Phantom
- Complete System
- NEMA MS 12-2016 → Compliant
- Uses a novel method for quantifying 3D geometric distortion in MRI based on 3D harmonic analysis
- Features an XYZ orientation and scale cuboid containing fiducials channels to easily visualize the phantom isocenter
- Contains 1,496 precisely machined 3mm fiducial markers uniformly distributed around the phantom surface boundary
- Contains 6 precisely machined 5mm reference fiducials to detect image position when distortion is high or correction is off
- Acquire T1 weighted 3D isotropic GRE scans at 3T under 5 minutes or at 1.5T as quick as 10 minutes
- Enables users to easily visualize analysis results and update visually stunning charts, graphics and plots in real-time
- Ability to update statistical analysis in real-time within a selected region of interest (ROI)
- User selects 2 identical MR scans with opposite frequency encode polarities to compare B0 vs Gradient distortion
- Software automatically locates fiducials, compares it against the truth and calculates the geometric distortion for QA analysis
- Track results over time to identify patterns, prevent potential errors and make adjustments to improve patient care
- Capable of exporting the entire 3D Distortion Vector Field (DVF) data into Microsoft Excel (.CSV) format
- Save distortion measurement results in PDF format to share with physicist, MRI technician and radiation therapists
- Designed for multiple QA applications including MRI-guided radiation therapy, MR simulation and diagnostic imaging
- 37cm x 32cm (W x L) phantom enables users to accurately simulate and QA treatment plans for a wide range of patient sizes
- Phantom weighs 21 kg for easy and fast setup compared to similar sized water-based phantoms that weigh 41 kg or more
- The removable end plate, XYZ cuboid and fiducial markers are delivered pre-filled with mineral oil for best scanning results
- Maintenance free phantom comes complete with XYZ cuboid, analysis software and instructions for safe assembly
- Phantom design permits fast, accurate, large 3D volume scanning in under 5 minutes
Watch the Demonstration Video →
A video demonstration of the QUASAR™ MRID3D software analysis features for quantifying geometric distortion in 3D MR images.
Read the latest Press Release →
Modus QA Updates MRI Geometric Distortion QA Analysis System with faster isocenter detection, improved fiducial markers, convenient alignment crosshairs and additional visualization tools, making the fastest, lightweight, large field of view MRgRT QA Phantom better than ever.
INNOVATIVE DESIGN & FUNCTIONALITY
Features an XYZ orientation and scale cuboid containing fiducial channels to enable users to easily visualize the phantom isocenter
Contains 1,496 precisely machined 3mm fiducial markers and 6 contrastive 5mm central reference fiducials for robust position detection when imaging distortion is high or while geometric correction is turned off
Designed to work with the MRI laser positioning system to ensure that there is no roll, pitch or yaw displacement of the phantom
Integrated Feet and Handles
Comes with built-in 3 point contact feet for quick set-up on uneven surfaces and recessed handles for convenient carrying and easy storage
Pressure/vacuum sealed fill ports to lock-in mineral oil and prevent leaks due to changes in temperature
Integrated mineral oil thermal expansion tubes, made of blue fluorosilicone rubber, provide internal pressure relief to ensure geometric stability
The maintenance free phantom comes pre-filled with high T1 weighted contrast mineral oil for faster 3D scanning and dielectric-resonance-free use at high 3T fields. At 21 kg it is half the weight of conventional solid fluid filled grid phantoms for lighter, convenient one person setup.
The patent pending temperature compensating oil expansion reservoirs maintain geometric dimensional stability of the phantom when temperature variations are experienced in use. This eliminates a potential source of measurement error commonly found in large conventional grid phantoms, and ensures safe, leak-proof shipping.
The mineral oil is susceptibility matched to acrylic to render susceptibility artefact negligable around the control points. The physical dimensions of the phantom are 39.4 cm diameter by 39.1 cm long – with a hollow internal volume of ~25 liters, effectively removing 25 kg of weight relative to conventional solid fluid filled grid phantoms.
A small insert at the center of the phantom includes an XYZ orientation and scale cuboid to register a calibrated frame of reference and to facilitate auto pre-scanning 3 plane MR Image localizers.
The system includes mature, robust and intuitive client-based MR image distortion analysis QA software.
Figure caption: 3D comparison of Control Point Image locations (yellow) vs Truth Template from CAD data (green) to calculate Boundary Distortion Vector Field (red) from the difference between control point image location and truth. Results are easily visualized in 3D.
The robust QUASAR™ MRID3D software automatically identifies the location of the control points in acquired images of the phantom under conditions of low or high distortion e.g. with vendor geometric distortion correction turned off. The results are shown graphically in a 3D display and numerically in a spreadsheet.
The software is compatible with Windows 7 or higher operating systems.
Automated processes are used to identify location of Control Points, quantify Geometric Distortion, calculate Distortion Vector Fields and produce Statistical Analysis.
Complex equations and algorithms are put to use to calculate the phantom Boundary Distortion Vector Field, Volumetric 3D DVF and B0 Distortion vs Gradient Distortions.
Enriched analysis tools make it easier to examine the geometric distortion measurements of a single acquisition or compare the distortion among a collection of series.
Sophisticated 3D DICOM Viewer with ROI selector enables users with the ability to update charts and graphs in real-time to user-defined volumes to gain further insights.
Interactive statistical graphics allow users to explore, discover, summarize and visualize quantitative data in the way they see fit to form conclusions and make decisions.
Control how your data is managed by adjusting settings, image viewer properties, graphic resolution display, change plot line colours and configure the database path.
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Product Data Sheet
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