Mbirn: Calibration Code developments

Updates

• May 17, 2005 (S. Mori)
  • Gradient non-linearity distortion correction: JHU phantom scans completed
    • Philips scanner has two setting of gradient performance. One is rapid / low strength and the other is slow / high strength. Measurements were done in both modes.
    • Philips doesn't use gradient linearity compensation for post-processing for the 1.5T scanner (4G/cm system).
    • Philips' new gradient system (8G/cm) system in 3T does use linearity correction. I talked with a Philips person about the disclosure of the linearity information but I couldn't get clear answer about it.
    • I'll measure the linearity in the 3T system after ISMRM.
    • This data will be uploaded to the SRB using JHU's rack, and then inspected at MGH to assess the degree of distortions.

• Jan 20, 2005 (J. Jovicich)
  • Gradient non-linearity distortion correction: S. Czanner extended the gradient unwarping code to operate on Siemens Avanto (1.5T). He is currently re-writting the matlab scripts so that we can have a stand-alone that can be distributed without proprietory information. This version will take as input the vendor-specific information that we use for the correction.

---