• Discovery MR750 3.0T System Service Methods
  • 5690009-2EN Revision 4
  • Object ID: 00000018WIA30622750GYZ
  • Topic ID: id_2025571 Version: 1.2
  • Date: Oct 11, 2021 6:13:21 PM

Probe/SV SNR testing

Topic ID: id_SL317692-1060211

Probe/SV SNR Procedure

About this task

Use the MRS phantom (without the loader) for the signal-to-noise ratio (SNR) procedure. Enter the most visible number of the temperature strip as a Control Variable (tempC).

Topic ID: id_SL1952014-1060211

Probe-S SNR Procedure

Procedure

  1. Note:

    Use the MRS phantom for all SNR procedures. Position the MRS phantom centered on the head coil. Use foam padding as necessary to center the phantom in the head coil. Phantom centering (up/down/left/ right/in/out) is important. Run any head localizer to ensure the phantom is properly centered before beginning the Probe-S SNR procedure.

    Select Create new worklist.
    1. Patient ID: geservice
    2. Name: probe snr
    3. Weight (lb.): 111
    4. Select Show All Protocols.
    5. Select Protocol Library option Service and select Other tab. Scroll through the list to the protocol Probe-S SNR. Select Series 1 and Accept, and then click Start Exam.
    6. Click the arrow next to the Scan Time indicator to expand the scan prescription area.
    7. Click the Advanced tab. Enter the temperature that is noted on the phantom.
  2. Click Save Rx.
  3. Click the arrow next to the Scan option, and then click Auto Prescan.
  4. Select Message Window, which is located in the bottom center of the scan desktop. Record R1, R2, TG, AX (and if present, record FWHM, WS Angle, WS%) on the Data Sheets. Close the window.
  5. Select Scan.
  6. Display the image, and record the displayed results of CR SNR on the Data Sheets for Probe-S SNR.
  7. Note:

    You must perform a minimum of three scans (back to back) to get an estimated average Probe-S SNR.

    Repeat Step 5 through Step 6 three times to get an average Probe-S SNR (C-SNR).

    Probe-S SNR specification minimum is:

    50.0 Cr SNR for 3.0T

Topic ID: id_SL1952035-1060211

Probe-P SNR Procedure

Procedure

  1. Note:

    Use the MRS phantom for all SNR procedures. Center the MRS phantom on the head coil. Use foam padding as necessary to center the phantom in the head coil. Phantom centering (up/down/left/ right/in/out) is important. Run any head localizer to ensure the phantom is properly centered before beginning the Probe-P SNR procedure.

    Select Create new worklist.
    1. Patient ID: geservice
    2. Name: probe snr
    3. Weight (lb.): 111
    4. Select Show All Protocols.
    5. Select Protocol Library option Service and select Other tab. Scroll through the list to the protocol Probe-P SNR. Select Series 1 and Accept, and then click Start Exam.
    6. Click the arrow next to the Scan Time indicator to expand the scan prescription area.
    7. Click the Advanced tab. Enter the temperature that is noted on the phantom.
  2. Click Save Rx.
  3. Click the arrow next to the Scan option, and then click Auto Prescan.
  4. Select Message Window, which is located in bottom center of the scan desktop. Record R1, R2, TG, AX (and if present, record FWHM, WS Angle, WS%) on the Data Sheets. Close the window.
  5. Select Scan.
  6. Display the image, and record the displayed results of CR SNR on the Data Sheets of the Probe-S SNR.
    Note:

    You must perform a minimum of three scans (back to back) to get an estimated average Probe-S SNR.

  7. Repeat Step 5 through Step 6 three times to get an average Probe-P SNR (C-SNR).

    Probe-P SNR specification minimum is:

    100 Cr SNR for 3.0T

Finalization

Remove all service equipment from the system.