• Discovery MR750w and SIGNA™ Architect T 3.0T System Service Methods
  • 5690002-2EN Revision 4
  • Object ID: 00000018WIA3091FE20GYZ
  • Topic ID: id_13106552 Version: 3.8
  • Date: Nov 30, 2021 2:00:13 PM

System Gain Calibration (for systems DV26 or earlier)

Body system gain calibration.

Prerequisites

Table 1. Personnel requirements
Required personsPreliminary requirementsProcedureFinalization
15 minutes10 minutes2 minutes
Table 2. Tools and test equipment
ItemQuantityEffectivityPart numberManufacturer
Foam Support for ECMT and Phantom1-

5554839

-
Table 3. Required conditions
ConditionReferenceEffectivity

No required conditions.

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About this task

System gain calibration is performed to determine the body recon scale factors that will achieve a known level of image intensity when using the body coil with a known phantom solution and protocol. The goal is that when the same solution or tissue is scanned in either the standard body coil with the same protocol, those tissues will have approximately the same image intensity level on a given system and between systems of like type.

This calibration accounts for differences in body receive coil sensitivity, preamp gains, cable loss, receiver gain, and other factors. The calibration must be done on body at least once to calibrate those paths.

Topic ID: id_SL3890161-1178717

Preliminary Setup

Procedure

  1. Move the Cradle 320 mm from Home Position and Landmark, but do not advance to scan.
  2. Run the cradle in so the display reads 1135 mm.
  3. Place the body loader on the GEM foam phantom positioner. Turn on the alignment light and then position the body loader on the cradle so that the alignment light is properly centered on the loader crosshair.
  4. Press Advance to Scan.
  5. Start the System Gain Calibration tool:
    1. (For non-proprietary service tools) From the Common Service Desktop, select Calibration > System Gain Calibration. Select Click here to start this tool.

    The System Gain Calibration window appears.

Topic ID: id_SL1774744-1178717

Calibration

Procedure

  1. At the System Gain Calibration Test Modes menu, click Start button. The calibration begins.
    Figure 1. Starting System Gain Calibration Tool
  2. The calibration results display on the screen. If adjustments are required, the system asks, Do you want to save the recon scale factor. Type Y and press Enter to save the recon scale factor.
    Figure 2. Calibration Output
  3. Click Quit button to exit the tool. The calibration is complete.
Topic ID: id_15006924

Finalization

Procedure

  1. Remove all phantoms and service tools from the patient table.
  2. If you are performing this calibration during an installation, continue with the required calibrations. Otherwise, perform a SaveInfo to save the new ReconScale values.