• SIGNA™ Hero 3.0T Service Methods
  • 5852800-8EN Revision 1.0
  • Object ID: 00000018WHA305872GYZ
  • Topic ID: id_2001635 Version: 15.1
  • Date: Nov 24, 2021 4:37:43 PM

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.

Prerequisites

Personnel requirements
Required personsPreliminary requirementsProcedureFinalization
1-30 minutes (varies)10 minutes
Tools and test equipment
ItemQuantityPart numberManufacturer
DQA III Phantom12321556-
Table 1. Tools and test equipment
ItemQuantityEffectivityPart numberManufacturer
DQA III Phantom1-2321556-
Required conditions
This procedure requires an accurate landmark. Make sure the laser light alignment is complete. Troubleshoot any problems you find while doing this calibration.
ConditionReferenceEffectivity

Laser light alignment completed.

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Safety

Before working in any GE Healthcare MR suite or performing any GE Healthcare service procedure, you must:

  • Have read and understood all hazard conditions and safety requirements in the latest revision of the GE Healthcare MR Service Safety Manual (5452735).
  • Have successfully completed all relevant GE Healthcare Environmental Health and Safety (EHS) courses (or for non-GE employees, equivalent workplace training courses).
  • Comply with all site-specific training and workplace safety requirements.

If you have any safety concerns at any time, do not begin work or immediately stop work and move to a safe location. Immediately contact your supervisor or site safety officer for instructions on how to proceed.

About this task

The DQA tool determines proper gradient polarity (positive to positive and negative to negative) and proper gradient wiring (X amp drives X coil, Y amp drives Y coil, Z amp drives Z coil) by scanning a series of axial and coronal images of the DQA III phantom. The tool also verifies that the proper phantom is being used. After proper gradient orientation is confirmed, the tool adjusts for Z isocenter and gradient calibration. If Z iso adjustments or gradient calibration adjustments are required, the DQA tool performs the appropriate iterations to complete. Therefore, the DQA tool time to complete may vary.

Procedure

  1. Verify that Checking and aligning the laser light was completed. Pay close attention when positioning the alignment light on the phantom, because this procedure requires an accurate landmark.
    If problems are encountered while doing this calibration, refer to Troubleshooting the Calibration Tool Troubleshooting the Daily Quality Assurance (DQA) II tool.
  2. Follow the steps below to place the DQA III phantom on the table.
    Figure 1. Phantom positioning on table
    Note: This image is a representative example. Actual systems may vary.
    1. Place the phantom positioner onto the hollow for HNU. R/L direction will be fit to the hollow.
    2. Push the phantom positioner toward the magnet until the two bottom bars reach the end of the hollow.
    3. Place the phantom onto the positioner and verify it is level and not rotated.
  3. Landmark on the center line of the DQA III phantom. The laser must be in the middle of the black circumferential line on the phantom.
    Note: Never use the touch-and-go landmarking strip when manually landmarking as part of a calibration tool procedure.
  4. Start the DQA tool:
    • (For non-proprietary mode) From the Common Service Desktop, select Calibration > DQA Calibration, then click Click here to start this tool.
  5. In the new window that displays, click Start.
    Figure 2. DQA tool
    All phantom images acquired during the DQA tool can be viewed in the browser. View these images if problems occur.
    To stop the DQA tool without restarting it, click Abort at any time.
  6. As the DQA tool progresses, the status displays in the Progress area. If problems are encountered, they display in the Actions Required area.
    Figure 3. DQA screen with actions required
    Note: After resolving the issues in the Actions Required section, click Restart to restart the DQA tool.

    Result

    A pop-up dialogue will ask if you want to update the config file with the new values.
  7. After the tool successfully completes its tasks, click Exit.
    Figure 4. Successful test
    Note: The finalization steps are included at the end of this procedure.
  8. Review images to verify proper body scan.