SIGNA™ Hero 3.0T Service Methods
5852800-8EN Revision 1.0
Object ID: 00000018WIA305EEE20GYZ
Topic ID: id_13106288 Version: 3.17
Date: Oct 28, 2021 11:36:51 AM

Body Coil Tuning

Prerequisites

Table 1. Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
1	-	-	-

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
USB Memory	1	-	-	-
USB Mouse (For Network Analyzer operation)	1	-	-	-
Network Analyzer Service Tool Kit	1	-	, 5336593-3, or 5336593-4	-
Body Loader w/ Sphere Phantom	1	-	2371511	-
FOAM SUPPORT ECMT AND PHANTOM	1	-	5554839	-

Table 3. Safety

Warning

Strong magnetic field

Ferrous materials can become dangerous projectiles in the presence of the magnetic field that the magnet produces.

Do not bring any ferrous tools or equipment into the magnet room.

Notice

System must be in scanning condition with system air and water cooling in proper operation.

Notice

RF body coil temperature must be stable and match magnet room temperature.

Table 4. Required conditions
Condition	Reference	Effectivity
Body Coil Isolation is done.	-	-
System must be in scanning condition	-	-
RF body coil temperature must be stable and match magnet room temperature	-	-

About this task

Body Coil Tuning is performed by adjusting Variable Capacitors (VC1, VC2, VC3) to tune f1, f2, f3, and MagS21 according to the navigation of the Network Analyzer screen.

Note: This procedure describes the normal tuning procedure. If there is any problem regarding Body Coil Tuning such as Network Analyzer Display problem or Abnormal plots, refer to Body Coil Tuning Troubleshooting.

Topic ID: id_SL3911442-1178721

System Pre-setup for Tuning

Procedure

Perform the following sub-steps to set up any body coil scan on scan window to setup driver module body BIAS mode.
1. On the exciter/ref clock module located in the Pen or ISC cabinet, set the RF ENB switch down (Disable).
  
  Figure 2. Exciter/ref clock module
2. At the magnet control panel, press [In] button so the cradle advances into the bore until enclosure display indicates 800mm position.
3. At the magnet control panel, press [Alignment Light]. Then press the [Landmark] and [Advance to Scan] buttons sequentially to advance empty cradle to the magnet isocenter.
4. At the operator console, set up any body coil scan on scan window to setup driver module BIAS mode. The following steps are example of body coil scan setup.
  1. Click the New Patient Icon.
  2. Enter “geservice” for Patient ID and 111 lbs for Weight. Then click [Start Exam] at bottom right.
  3. In the Protocol Selector, select Service from the Protocol Library. Select “snr_check and SNR Body Axial, FuncChk:Sys. Then click the [>] (right arrow) icon. Protocol is transferred in right field (Multi Protocol Basket).
  4. Click [Accept] for Protocol Selector.
  5. Click [Save Rx] to download body coil scan parameter.
  6. Left click on [Scan] and select 'Manual Prescan' from the pulldown.
  7. Allow the scanner to pulse once, then select [Done] in the Manual Prescan window.
    
    Note: The driver module should now be supplying correct DC bias for tuning the body coil (-13.6VDC).
  8. Perform “End Exam” from pull down menu of scan window (End / End Exam).
5. Move the cradle to home position using the home button.
Remove the following components:
1. Undock the dockable patient table and move it away from the magnet.
2. Remove the magnet left-hand lower access panel, dockable table interface cover, and bridge cover. Refer to Removing the bridge cover.
3. Remove the rear service access panel. Refer to Removing the magnet rear service access panel.
The body coil tuning driver is located behind the bridge cover. It will be used to tune the variable capacitor.

Figure 3. Remove the cover to access the tuning driver
Place body loader with phantom on the foam support, place them on the bridge, and push them into the magnet center so that front edge of body loader is 822mm (32.4 inches) away from the front edge of the bridge.

Figure 4. Body loader setup

Note: Pioneer system is shown. This applies to both Pioneer and Hero systems.

Topic ID: id_SL3911426-1178721

Calibration of the network analyzer

Procedure

CAUTION
Electric Hazard !!
Please make sure DC Cable is not connected to Bias T.

Connect Bias T at Port1 and Port2. Do not connect the Bias cable at this time.

Figure 5. Bias T installation

Notice

Use AC wall outlet and do not use AC outlet at ISC. ISC might be shutdown during the procedure, but need to keep Network Analyzer power ON throughout Body Coil Tuning to keep activating calculated data in macro.

Note: Recommend to connect a mouse to one of the USB ports on the network analyzer.

If not using the mouse, it is necessary to use hard key. For example, select [Menu] hardkey and then use arrow (<, >) hardkeys to navigate and highlight, and [ENTER] hardkey to select from menu.

Power ON the network analyzer. If no power seen confirm AC power switch on rear of unit in 'I' position.

If the network analyzer is not ready, start either the ZVL Analyzer (5336593-3) from the Windows screen, or the Vector Network Analyzer (5336593-4). (This step might not be needed.)

Figure 7. Start ZVL Analyzer (5336593-3)

Figure 8. Start Vector Network Analyzer (5336593-4)
For Vector Network Analyzer (5336593-4), do the following to change the Preset mode to Network Analyzer:
1. Press Setup.
2. Click System Config.
3. Click VNA.
4. Close the window.

Select Pioneer 3T body coil tuning, based on your network analyzer:

Option	Description
For ZVL Analyzer (5336593-3)	Select Nwa-Setup > External Tools > Pioneer 3T Body Coil Tuning.lnk. Figure 9. Pioneer 3T Body Coil Tuning.lnk
For Vector Network Analyzer (5336593-4)	Select the Start menu, and then select Pioneer 3T Body Coil Tuning. Figure 10. Pioneer 3T Body Coil Tuning

Notice

If “Pioneer 3T Body Coil Tuning.lnk” does not show up, it is necessity to update the software in NWA. Please find the iso file in DOC1784686 in MWS, create CD-ROM, then copy the files in GE supplied USB memory to install software to NWA. Software installation procedure file is also stored in iso file.

The following screen shows up. For button selection, proceed to Step 7.

Select button shown in Figure 11 per following instruction.
1. If calibration of the network analyzer has not been done yet, click [OK] to start the calibration. Then, go to Step 8.
2. If calibration of the network analyzer has already been done and the following conditions are satisfied, click [Skip] to skip the calibration and go to equipment setup.
  - The current setup is the same as last calibration.
  - It is less than 1 day since last calibration.
  - No other calibration has been run on network analyzer.
  1. If [Skip] is clicked, the confirmation screen shown in Figure 12 comes up. Confirm the condition again and click [OK]. Then, go to Body coil tuning using network analyzer navigation.
  2. If any condition is not satisfied, click [Quit] button, then press the blue Pre-Set hard-key button on front left side of unit, and start the tool again.
    
    Figure 12. Confirmation screen
When [OK] is selected at Step 7, the following message comes up. Confirm that DC cable is not connected to Bias-Ts and click [OK].

Figure 13. Message
Connect N(m) to N(m) coaxial cable to Bias T of Port1. Refer to Figure 14.

Figure 14. Cable Connection 1

Note: Do not touch the cable ends and minimize human interaction during network analyzer calibration, as this can change the Impedance of the calibration setup.
Also it is best to not cross the cables, and route so that they are parallel and separated from each other as much as possible.

Note: It is recommended that the 50 ohm load (Match Standard) be measured with a DVM to confirm that it is operational (50 ohms +/- 5 ohms). Connecting it to end of BNC-f to BNC-f adapter or BNC-f to N-m adapter and measuring through opposite end of adapter sometimes provides most reliable electrical connection for measurement.
Connect female barrel and “BNC female to N male” to the end port 1 of the channel 1 cable. Do not attach any BNC 'Standard' connectors. Click [OK] when the following message is displayed. Do not make any changes until prompted.

Figure 15. Message for OPEN

Note: It will take about 15 seconds to display next message after clicking [OK] .
Connect Short standard to “BNC female to N male” and click [OK] when the following message is displayed.

Figure 16. Message for SHORT
Remove Short, connect 50 Ohm load standard and click [OK] when the following message is displayed.

Figure 17. Message for MATCH Standard (50 Ohm Load)
Using 2nd set of unused hardware, repeat Step 9 through Step 12 for port 2.
Connect port 1 and port 2 cables through female barrel.

Figure 18. Cable Connection 2
Click [OK] when the following message is displayed. Calibration is complete.

Figure 19. Message for THROUGH Standard
Once calibration is completed, the following screen comes up. Proceed to “Tuning Cable Connection (Equipment Setup)” by referring to Tuning cable connection (Equipment setup). Keep Network Analyzer screen as it is during “Tuning Cable Connection (Equipment Setup)”.

Figure 20. Message for Equipment Setup

Topic ID: id_SL5108032-1178721

Tuning cable connection (Equipment setup)

Procedure

Warning

Strong Magnetic Field!

Network analyzer must remain outside magnet room at all times.

Never take network analyzer in magnet room.

Connect the cables to the network analyzer as following illustration.

Disconnect cables for J2, J7, J8 and J3 from the DTR switch.

Connect the cables removed from the J2, J7, J8 and J3 to BNC extension cables which go to the network analyzer.

Table 5.
Cable removed from TR switch	Extension Cable	Connector	Body Coil/Bias Cable
J2	N(M)	N(M)	Body coil 1 cable
J7	MHV(F)	BNC(M)	Bias cable from driver module
J8	MHV(F)	BNC(M)	Bias cable from driver module
J3	N(M)	N(M)	Body coil 2 cable

At the network analyzer:
- Check the proper voltage on the removed cables from J7 and J8. Voltage should be approximately –13.6 VDC on each cable (measured between center conductor (-) and outer collar (+) of the connector).
- Connect body coil 1 cable to port 1 Bias T.
- Connect body coil 2 cable to port 2 Bias T.

Topic ID: id_SL3911454-1178721

Body coil tuning using network analyzer navigation

Procedure

Once tuning cable connection (equipment setup) is completed, click [OK].

Figure 22. Message for equipment setup

Ch1 measurement will start. Click [OK] to record f1.

Note: In case the following screen comes up, it means S11 Magnitude is unusual.

Figure 24. Message for unusual S11 Magnitude

In this case, please check the following conditions.

The cradle is not located in the magnet bore.
Bridge is installed in the the magnet.
Phantom is setup correctly per the System Pre-setup for Tuning section.
Cables are connected correctly per System Pre-setup for Tuning section.

Driver module DD bias in 'Body' mode. (-13.6VDC unloaded. ~2.6VDC Loaded, Exact voltages not critical.)

Notice

In case DD Bias is in Head Mode, the voltage is ~145VDC (Unloaded). If you need to measure DD bias voltage, please be careful to avoid creating an electrical short between center conductor(-) and outer collar(+) of the connector not to damage any equipment.

Once problem is corrected, click [Retry]. If there is no problem for the condition above, click [Ignore].

Ch2 measurement will start. Click [OK] to record f2.

Note: In case the following screen comes up, it means S22 Magnitude is unusual.

Figure 26. Message for unusual S22 Magnitude

In this case, please check the following conditions.

Cradle is not located in the magnet bore.
Bridge is installed in the the magnet.
Phantom is setup correctly per System Pre-setup for Tuning section.
Cables are connected correctly per System Pre-setup for Tuning section.

Driver module DD bias in 'Body' mode. (-13.6VDC Unloaded, ~2.6VDC Loaded, Exact voltages not critical.)

Notice

Once problem is corrected, click on [Retry].

From here, display on the network analyzer will navigate the operation. Follow the instruction shown in the display of the network analyzer.

Note: If the body coil is within specification, a pop-up which is shown in Figure 36 will appear. You are done tuning.

If VC1 CW or VC1 CCW is shown, turn VC1 using stick to tune f1 until [VC1 TUNED!] is displayed. Once [VC1 TUNED!] is displayed, click [OK] to go to next step.

Figure 27. Display

Figure 28. Tuning

Note: There are two ports for VC1 and you can adjust either one. If the one reached to the limit, turn the other one for adjustment.

Notice

If both ports for VC1 reached to the limit, click on the appropriate button to go to the next step.

If VC2 CW or VC2 CCW is shown, turn VC2 using stick to tune f2 until [VC2 TUNED!] is displayed. Once [VC2 TUNED!] Is displayed, click [OK] to go to next step.

Note: There are two ports for VC2 and you can adjust either one. If the one reached to the limit, turn the other one for adjustment.

Notice

If both ports for VC2 reached to the limit, click on the appropriate button to go to the next step.

If VC3 CW or VC3 CCW is shown, turn VC3 using stick to tune f3 until [VC3 TUNED!] is displayed. Once [VC3 TUNED!] Is displayed, click [OK] to go to next step.

Notice

In case VC3 tuning cannot be adjusted, turn the VC3 to CCW limit once and start adjustment.

Notice

If VC3 reached to the limit, click on the appropriate button to go to the next step.

Note: If VC3 Tuned does not display even though tuning is performed according to the displayed instruction, select [VC3 CW Limit] or [VC3 CCW Limit] and start VC1 tuning per displayed instruction. If the VC1 Tuning and VC2 tuning are completed properly, the dialog box shown in Figure 34 will display. Turn the VC3 to CCW limit according to the displayed instruction and select [Retry]. Then, VC3 adjustment will be available.

Note: In case the following screen comes up, it means S11, S22, or S21 Magnitude is unusual.

Figure 33. Message for unusual S11, S22, or S21 Magnitude

In this case, please check the following conditions.

The cradle is not located in the magnet bore.
The bridge is installed in the magnet.
Phantom is setup correctly per System Pre-setup for Tuning section.
Cables are connected correctly per System Pre-setup for Tuning section.

Driver module DD bias in 'Body' mode. Driver module DD bias in 'Body' mode. (-13.6VDC Unloaded, ~2.6VDC Loaded, exact voltages not critical.)

Notice

Once problem is corrected, click on [Retry].

If you see the screen shown in Figure 34, turn the VC3 to CCW limit according to the displayed instruction and click [Retry] to start tuning.

Note: If you see this screen second time, turn the VC3 to CCW limit and click [Retry] and try again.
If you see this screen three times or more, click [Quit]. It will navigate to troubleshooting.

Figure 34. RETRY or QUIT message

Once the following screen comes up, click [OK] to start the calculation.

Figure 35. Record data screen

Measured data is calculated and the result is shown on the display. Proceed per result as follows.

Note: The measured data will be archived in the following directory of the network analyzer.

C:\Program\Pioneer 3T Body Coil Tuning
File Name example: September 19, 2012 @ 5_35 PM Data.txt

Select ‘Firmware Exit’, ‘My Computer’ to save to USB memory stick.

Notice

It is recommended to save measured data after all data are in pass condition. If you want to save measured data to USB memory stick under fail condition, it’s necessary to exit firmware and navigation of Network Analyzer will stop. In this case, you need to restart ZVL Analyzer and you need to perform extra steps for Tuning.

Once the screen shown in Figure 36 is displayed, Body Coil tuning is completed.　Go to #id_14939534__SL3911556-1178721.

Note: The value in following screen is an example. Check the Pass or fail result.

If any of result is failed, following kind of screen shows up. Click [OK] and follow the navigation screen to perform more tuning.

Note: The value in following screen is an example. Check the Pass or fail result.

Figure 37. Measured data (Failed)

Topic ID: id_SL4908620-1178721

Troubleshooting

Procedure

If the following screen is shown, perform body coil troubleshooting.

Perform Body Coil Isolation.
Confirm bridge alignment and height correct per installation manual.
Check phantom position.
Replace the body coil.

Topic ID: id_14939534

Finalization

Procedure

Record final values.

Table 6. Final Value
Parameter Final Value
f1 MHz
f2 MHz
|f1 - f2| MHz
f3 MHz
S21 dB
Restore the cables and phantom. Restore the Bridge cover, dockable table interface cover, and magnet left hand lower access panel. Refer to Installing the magnet left-hand lower front cover and Installing the bridge cover.
On the Exciter/Ref Clock module located in the Pen or ISC cabinet, set the RF Enb switch up (Enable).

Figure 39. Exciter/ref clock module
Run the TR Dynamic Disable Calibration.
Run the System Gain Calibration.
Run the DD Quadrature Calibration .
Run the Echo Planar Test (EPT).
Perform a quick head and body scan to ensure the system is functioning properly.

Table 6. Final Value
Parameter	Final Value
f1	MHz
f2	MHz
\|f1 - f2\|	MHz
f3	MHz
S21	dB