• Discovery MR750w and SIGNA™ Architect T 3.0T System Service Methods
  • 5690002-2EN Revision 4
  • Object ID: 00000018WIA30522750GYZ
  • Topic ID: id_2025570 Version: 1.2
  • Date: Nov 5, 2020 1:37:49 PM

Probe/P tuning

Procedure

  1. Refer to Data Sheets for the tuning data sheet.
  2. Position the phantom in the single channel head coil. Do NOT use the head loader with the MRS phantom. Use foam support pads for quick alignment to center the phantom in the head coil. Phantom centering (up/down/left/right/in/out) within 5 mm of the isocenter in all directions is important. Landmark on the center of the phantom.
  3. Run a 3-plane localizer to make sure the MRS phantom is properly centered. If necessary, run an additional 3-plane localizer. Once the phantom is centered, make sure the phantom remains stationary for at least 5 minutes before the start of any Probe calibration scan. (This is to allow the fluid in the phantom to reach equilibrium and to minimize the effects of long-term eddy currents.)
  4. Start the Probe/P Tune Tool.
    1. (For non-proprietary service tools) From the Common Service Desktop, select Calibration. Select Probe/P Tune from the Calibration menu, and select Click here to start this tool to start the procedure.
  5. At the Probe/P Tune popup, press Enter. The calibration begins as shown below.


                         Probe-P Cal Started

    xshim= -1 yshim= 5 zshim= 2
    APS: R1=13 R2=30 TG=190 CF=127762262
    deltay_val: -0.670430
    Y Axis Calibration completed Successfully
    deltax_val: 0.576271
    X Axis Calibration completed Successfully
    deltaz_val: -0.180328
    Z Axis Calibration completed Successfully
                      

    This message appears after the completion of the three axes:


                         Probe/P Tuning completed successfully
    Results are stored in /usr/g/caldir/probep_cal.log
    Press [Enter] to quit -->
                      

    Press CtrlC to stop the tool.

    This test takes about six minutes.

  6. To view the complete results (which do not contain auto pre-scan (APS) information):
    1. Note: The Shell window can only be launched when the EA3 user is included in the authorized EA3 group. Users not in this EA3 group will not have access to launch the Shell window. If you are not logged on as the proper logon user, log out and then log back on as the correct EA3 user with the authorized permissions.
      Select C Shell.
    2. Type: more /usr/g/caldir/probep_cal.log.
    Note:

    If the calibration log file is not available, perform a TPS reset and repeat these steps to view the log file.

  7. The specification criteria (absolute value) are:

    • Single delta parameter, < 0.8

    • Sum of all delta parameters, < 1.0