MR-guided Stereotactic Radiosurgery QA.


The QUASAR™ GRID3D Image Distortion Analysis System is designed to evaluate image distortion in 3D MR images for stereotactic radiosurgery (SRS).

The system is comprised of a phantom and analysis software which work together to produce a 3D map of spatial distortion with submillimetre accuracy throughout a volume of interest. The GRID3D System ensures that MR imaging can support the outstanding geometric precision and dosimetric accuracy of the Leksell Gamma Knife®, including PERFEXION™.

The phantom is an acrylic cube containing a 1 cm 3D grid of channels filled with copper sulphate solution.

The region of interest measures 14 x 13 x 11 cm3 in which there are 2002 vertex locations. The vertex locations are known to within 0.1 mm. The phantom accurately and reproducibly mounts securely to the Leksell® Coordinate Frame G at a known position. It fits within both the Leksell® MR Indicator and Leksell® CT Indicator.

Key Features of the GRID3D

  • Verify geometric accuracy of different MR pulse sequences
  • Compatible with the Leksell Gamma Knife®, including PERFEXION™ (fiducial box is required)
  • Automated image analysis provides full 3D distortion map with submillimetre accuracy
An image of the QUASAR GRID3D brochure