• Discovery MR750 3.0T System Service Methods
  • 5690009-2EN Revision 4
  • Object ID: 00000018WHA3014C6GYZ
  • Topic ID: id_2001854 Version: 6.60
  • Date: Nov 3, 2021 6:28:32 PM

Configuring for LVShim

About this task

The configuring process is different depending on the type of software you are using. Please select the appropriate procedure for configuring for LVShim.
Topic ID: task_cbw_5lh_53b

Configuring for LVShim

Procedure

  1. Make sure that all coils have been removed from the cradle and phantoms from the bore.
  2. Set up and align the LVShim phantom. Align the phantom so that:
    1. The phantom’s seam is oriented perpendicular to the table.
    2. The phantom’s z-axis is along the length of the cradle.
    3. The phantom is centered left to right with respect to the cradle top.
    Note: This image is a representative example. Actual systems may vary.
    Figure 1. Placing the LVShim phantom on the patient table
  3. Landmark on the LVShim phantom crosshairs.
    Note: The landmarking tolerances of the LVShim tool are: I/S: ± 3 mm, A/P: ± 30 mm, R/L: ± 5 mm. Ensure accuracy of the placement for landmarking.
    Note: Due to the tight landmarking tolerance, it is important to align the lasers on the crosshairs of the LVShim phantom.
  4. Press Advance to Scan.
  5. Do a phantom centering check scan and center frequency check using manual prescan. Save the resulting frequency using Save Frequency.
  6. Start the LVShim tool from the Common Service Desktop on the Calibration tab. Click Calibration > Installation and Calibration, then select the shim to be performed (Gradient Shim).
Topic ID: task_rx2_vrh_ykb

Configuring for LVShim for or later

Procedure

  1. Set up and align the LVShim phantom. Align the phantom so that:
  2. Press Advance to Scan.
    Note: The tool checks phantom positioning and will fail if the above landmarking specs are out of tolerance.