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Adjustments/Calibrations
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Calibrating High Order Shim (HOS)
This procedure creates High Order Shim (HOS) reference maps characterizing the fields created by the HOS windings. These maps are used by the HOS feature.
Configuring for systems running DV29.1 and later

Adjustments/Calibrations
- System
  - B0 Drift Calibration
  - Doing DQA calibration
    The DQA tool determines proper gradient polarity and proper gradient wiring by scanning a series of axial and coronal images of the DQA III phantom.
  - Troubleshooting the Daily Quality Assurance (DQA) II tool
    If problems are encountered while using the Daily Quality Assurance (DQA) calibration procedure, refer to the following guidelines for troubleshooting.
  - Dual drive quadrature tool
  - Doing the Echo Planar Test
  - Deionization procedure
  - HIS/RIS Setup and Troubleshooting
  - Calibrating High Order Shim (HOS)
    This procedure creates High Order Shim (HOS) reference maps characterizing the fields created by the HOS windings. These maps are used by the HOS feature.
    - HOShim Reference Map Creation and Verification for DV26.0 or earlier
    - Configuring for systems running DV29.1 and later
    - Running High Order Shim (HOS) calibration
    - Doing a check scan
      A check scan is done at the conclusion of many procedures. This functional check assures the unit is in good clinical working order.
  - ICN On/Off procedure for Sun 4100, 4170, and Dell R620
  - LVShim Procedures
  - Running LVShim
    The objective of the LVShim tool is to fine-tune magnet homogeneity.
  - Running LVShim - Gradshim
  - Running LVShim in Auto mode
  - Running LVShim in Manual mode
  - System gain calibration
    Head and body system gain calibration.
- Gradient
- Radio Frequency (RF)
- Magnet Enclosure
- Patient Table
- Global Operator Console (GOC)
- Spectroscopy

Discovery MR750 3.0T System Service Methods
5690009-2EN Revision 4
Object ID: 00000018WIA308E5E50GYZ
Topic ID: id_2028293 Version: 1.6
Date: Mar 3, 2021 4:55:23 PM

Configuring for systems running DV29.1 and later

Procedure

Set the universal phantom pad on the table and align the crosshairs at 1080 mm away from home.
Put the sphere on the pad with the strap (in the groove) in the orientation shown below, making sure the laser lights are cross-centered on the sphere.

Figure 1. Sphere phantom position
Set up and align the LVShim phantom. Align the phantom so that:
1. The phantom's strap is parallel to the table surface.
2. The phantom is centered left to right with respect to the cradle top.
Landmark on the phantom pad crosshairs.

Note: The landmarking tolerances of the HOShim tool: I/S: ± 3 mm, A/P: ± 30 mm, R/L: ± 5 mm. Make sure the placement is accurate for landmarking. The HOShim tool will verify the placement of the phantom.
Press the Advance to Scan button.