Echo Planar Test (EPT)

Prerequisites

1 Startup

EPT combines the functionality of the current B0 Dither Calibration, Group Delay Calibration and B0 Image Test into a single tool with a simple user interface. The output is suitable for remote support access, trending, and automatic checking of results against acceptance limits. In addition, EPT automatically updates the EPI calibration files when authorized by the user.

Procedure

  1. Click on New Pt, and enter the following:

    ID: geservice

  2. Place an EPI foam phantom holder and a 100-mm sphere phantom and phantom loader in the head coil, as shown in Figure 1Landmark on the center of the sphere, but do not advance to scan yet.

    Figure 1. EPI Phantom Positioning

    Figure 2. Landmark Marker

  3. Place an EPI foam phantom holder and a second 100-mm sphere on the Grafidy base plate, as shown in Figure 3. Move the table into the bore to 1100 mm from landmark. Slide the Grafidy base plate so the center of the 100-mm sphere is at the axial alignment light, and then press the MOVE TO SCAN button.

    Figure 3. Landmark 100–mm sphere phantom

    note:
    When using the old head coil shown in Figure 1make sure phantom placement is correct prior to starting EPT by performing a 3-plane localizer scan. Before running the scan make sure that the offsets are set to zero, see Figure 4

    Figure 4. Scanning Range Offsets

  4. Start the Echo Planar Test Calibration Tool.

    • Starting non-proprietary service tools:

      1. From the Common Service Desktop, select [Calibration] .

      2. Select [Echo Planner Test] from the calibration menu, and select [Click here to start this tool] to start the procedure.

      Figure 5. Starting EPT

  5. Click the Start button.
  6. The Echo Planar Test Window will appear, as shown inFigure 6 .

    Figure 6. Echo Planar Test Window

    note:

    The “Select All Tests” default option is No.

  7. There are four option buttons on the screen that must be chosen before starting EPT:
    1. Selecting the Multi Passes button and entering an integer in the text box can perform more than one pass of the tests.
    2. One or more of the selected tests can automatically update the config files with new calibration data if the new data is within specs. Select Config Update before starting EPT.
  8. Select a Test Purpose from the pull-down menu.
  9. Two lines of comments can be entered, if desired. If no comments are entered, the text “NO COMMENT” will be entered into the results file.
    10. Notice Image
    • caution
    • Equipment Movement!
    • The test you are about to initiate will move the cradle.
    • Please take appropriate precautions to ensure that no one will be in its path.
  10. Select Start EPT. Running all the tests takes about one hour and will thoroughly test the EPI performance of your system. This is the recommended mode for baseline, PM, and initial problem-finding. The single test mode is meant to be used while troubleshooting. If possible, run the full set of tests at the end of your troubleshooting to verify system performance. While EPT is running, each test will be displayed in the message window indicating the amount of time the test requires to run.
    note:

    Actual run time of the test may not coincide with the countdown clock displayed on the interface.

  11. EPT will create many images. If applicable, a window will pop up to inform you that there is not enough space available.
  12. When the tests are complete, one of four messages shown below will appear:
    1. Your tests completed successfully, or
    2. A minor system problem has been detected. This problem is NOT expected to affect image quality, or
    3. A serious system problem has been detected. This problem IS expected to impact image quality, or
    4. EPT was unable to determine PASS/FAIL status of the tests.
  13. If the tests completed successfully, proceed to Finalization below.
  14. If the tests fail, open the Report Manager to view the test results and identify the failing tests.
  15. Select Quit EPT and confirm

2 Test Termination Procedure

Procedure

  1. If Quit EPT is selected, a confirmation window appears.
  2. If the EPT process is not shut down in an orderly manner, the service protocol directions may need to be reset. This can be done by opening a C-shell and typing the following:

    cd /usr/g/service/cclass/ept Enter

    resetept Enter

3 Finalization

Procedure

  1. Reset the TPS to bring the system back into a known mode.
  2. Do a test scan to ensure the scanner is working properly before customer turn over.