7T general info & troubleshooting

Overview page for 7T Achieva related information

Table operation

• When pulling the table out, stop when 'table out' LED turns on. Don't pull further than backside of bed. When undocking, the bed will be pushed back the remaining centimeter.
• Move table to fully outer position before resetting or undocking
• Do not set the lights above level 3

Manual operation

• Go to manual mode by pressing Stop: red lights on bore will turn on.
• Push the small safety handle/lever at the front bottom of the bed and push the bed in a few centimeters. Do this slowly!
• Pull the table back
• Press reset and retry normal operation
• Fully manual positioning: the bed is in the iso-center when aligned which the edge of the bore / 2nd pencil line on the bed.

Undocking/docking the table

Warning: not following the right undocking procedure will damage the equipment!

• When scanning with dualTx: Disconnect cables and remove interface boxes
• Pull table pins up (ensure they stay up)
• Undock

Resetting table

In case the table operation does not respond, try the following options:

• Follow manual operation, see above
• Press the in button longer (~5 seconds). After a while the table goes into some sort of stand by mode, a long press can wake it up again.
• Try stop/reset multiple times. Wait.
• 3-finger reset (takes 2 minutes). Wait. Repeated if needed.
• Undock table (follow procedure above). Wait 1 minute before docking.
• Manual undocking: upper switch at lower right hand of the magnet:
  • up: undock - careful: connector will come out of docking station!
  • center: ready to dock
  • down: dock(?)
• CDAS reset (see elsewhere on this wiki)

If table beeps, bed position is lost, probably caused by not resetting not in outer bed position. Follow manual operation, see above.

If all fails, the table can be pushed in manually:

• bed must be docked and connected.
• go to manual mode by pressing Stop: red lights on bore will turn on. Push the small safety handle/lever at the front bottom of the bed and push the bed in. Do this slowly! Pushing the bed in usually requires two persons on each side.
• The bed is in the iso-center when aligned which the edge of the bore / 2nd pencil line on the bed.

In all cases, call support, and/or Anton/Cor from Philips. Explain what was scanned/happened beforehand and report date/time.

Switching between 7T Achieva systems

Classic <-> MultiX

• Exit the scan environment of the system which was currently used (THIS STEP SEEMS OPTIONAL)
• Use Permproc stop scanner to disconnect the host being used from scanner.
• Unplug the rf-coil being used.
• Switch to other environment (using the switch next to scanner door)
• Use permproc start scanner on new host to be used.
• Run logd: CDAS will boot up. This takes 5-10 minutes. Wait for message: humidity of examination room (or NOMEASPARS in the logging browser)
• Meanwhile, connect the proper coil

System specific information

R5

Patches

Loading a patch:

• exit application software
• Run SmartPatch.pl from the Desktop
• logd wait for processes to finish then start software

Installing patches: G:\Site\ClinicalScience\Put All Patches Here

General

• SmartPatch:
  • after switching patches, WAIT for loading all boards etc. before starting application software. Inspect PatchReadyCheck tool
  • do NOT manually copy/paste/delete files in G:\patch. This directory links to the installation folder and will affect the installed patch files
• Shimtool: pride-folder should be present in G:\patch to automatically start shimtool as PRIDE process

Classic (dualTx, R5B)

• Does NOT automatically scan SENSEref and CoilSurvey

Making a new Reference Scan - Always Repeat Prescans

The scanner will always use the first valid reference scan for reconstruction. So for instance when removing patients from the scanner mid-session, a new reference scan needs to be made. Same goes for the case where the angulation of shimming of the reference scan was off. Importantly, if a new reference scan is made, always select "Repeat Prescans" from the menu to make sure this new reference scan is used!

Errors

• The MTX-Volume-T/R-coil needs 4500 watts where 3800 watts is allowed

B1 cannot be reached, lower value (to 17, 15 or lower, set to 15 in example below):

Check Contrast --> B1 mode: change from Default to 15.

For T1, FLAIR, MP(2)RAGE and other scans with inversion pulses: check Contrast --> Inversion control: max B1 (uT). Set to same value as B1 mode (also 15).

To find the detailed error message: Use logging application or log browser to query log file. Reported in log file as 'Average Forward Power Fault'.

One should try not the change the ref scales in System Tuning - however if you do, then keep the RATIO the same between the two ref scales for the two transmit channels (R5 Classic)!!!

Coil parameters are not set correctly. Perhaps not added to a patch? Check settings above.

MultiX

• Always have a classic host running for intercom communication
• SENSEref and CoilSurvey are automatically scanned whenever needed.

Tx testing: System Tuning --> Coil --> NOVA Head coil Transmit phases: 0, -45, -90, ..., -315 CCM-file, Datamonitoring tab --> CCM. Make screen shot when scanning.

MRCodetool

• B0 scan includes Exportdata pride tool
• start menu/desktop to open tool (installed in E:\Export\MRCodeTool)
• run unshimmed B0 to shim on

=> run B0shimming in MRCodeTool

• run shimmed B0 (for the B1 shim)
• FFE dyn scan (acquires FFE transmitting on each channel - output 8 images - input for B1 shimming)
• FFE quad scan (all 8 in quadrature - workaround for bug)
• B1 quad (B1 map (DREAM) - input for B1 shimming)

=> run RFshimming in MRCodeTool (minimizes standard deviation B1 over single (centre?) slice)

• in scans where you want to use the rf-shim, select contrast-rfshim-shimtool
• contrast-rfshim-predefined offers pre-calculated options (on models)

For SPINS pulses:

• B1map dyn (B1 map (DREAM leaving every run 1 channel out) - input for SPINS pulse calculation in addition to the above)
• Open the protocol you'd like to use your pulse in, change MTX pulse def id. to a non-used number (check on G:\Site\Waveforms)
• confirm that the protocol gives a conflict (non existing pulse)
• run SPINS module in MRCode
• confirm that protocol is no longer in conflict (pulse now exists)
• run scan

For MP2RAGE:

• load MP2RAGE protocol
• change end_rep_delay to desired value **NEEDS UPDATING**
• run MP2RAGE prot MRCode

Errors

• Error: Coil coupling matrix abnormal. Caused by scanning phantoms. Scan Control Parameters --> Preparation --> CCM switch off. Apply (Do NOT save). Revert back after finishing scanning phantom.

Software

MRCodeTool (MP2RAGE)

The MRCodeTool can deal with two types of MP2RAGEs: those acquired with the MISS (including T123DEPI and MP2RAGEME data and everything acquired with FatNavs) and those acquired with all other patches, also known as the 'cardiac phases' MP2RAGE.

For both modules (and the shimming) counts: if it hangs, you can press ctrl-alt-delete and remove the PulseClient and PulseServer processes, usually you can successfully start a second PRIDE job then.

• MP2RAGE (1 scan, all patches but MISS)

Use the MP2RAGE job. Only the PRIDE jobs will write data into the database (not the gui). The parameters for the T1-maps are taken from the file starting with variablesettings_... in E/Export/MRCodeTool/PulseClient/. Make sure you use variablesettings_clean.txt. If the file contains lines with 'inversiontime' then remove the file and replace it with original_variablesettings_clean.txt. The T1-weighted image and T1map can be viewed from the images tab on the scanner (i.e. not the list view).

• MISS MP2RAGE (multiple scans)

Two jobs are required: 1 export job on MP2RAGE_INV1 and 1 mp2rage (2 inputs) on MP2RAGE_INV2. Note that MP2RAGE_INV2 is typically the first scan in the queue. You need to select the right set of settings for your acquisition and rename the wanted .txt file to variable_settings_SOMETHINGRELEVANT.txt. Please put back the clean one after you finish! If there is no variablesettings file for your experiment, you can quite easily make one following the instructions below: FIRST_inversiontime_sec = inversion time MP2RAGE_INV1 / 1000 (because this is required in seconds but specified in milliseconds). SECOND_inversiontime_sec = (shot_interval MP2RAGE_INV1 + 0.5*TFE_dur_shot/acq(ms) MP2RAGE_INV2 )/1000 MP2RAGE_repetitionTime_sec = shot_interval MP2RAGE_INV1/1000 + shot_interval MP2RAGE_INV2/1000 + dyn scan time FATNAV (if present).

delayed reconstruction

Under R5 the data can be reconstructed (post-scanning) using some different recon parameters. Useful if you'd like to save also the separate coil images, calculate g-factors or interpolate differently. Raw data saving does need to be switched on, obviously.

1. On the post-processing tab of your protocol, switch on raw data saving
2. Following running of the scan, right-click on finished scan -> delayed reconstruction
3. Open the job it puts under your scan
4. Edit the parameters you would like to change(matrix size, saving separate coils, etc)
5. remove the waiting thingy.
6. wait. enjoy.

B1 shimming

• Export B1 as parrec and load in RFshimGUI
• Copy rfshims.dat from D: to G:\Site
• RF Shims: shimtool

MT B1 calibration scan scan UI --> full enables editing B1-scan parameters B1 field map: yes --> makes image instead of calibration scan

Text in log files: Reading G:\site\rfshims.dat am_scales=..., phases = 0 11

If RFshimGUI doesn't start (error: Undefined function or variable matlabrc), clear cache folder G:\Temp\Gyrotest\MCRCache

MultiX

Built-in RF shimming is (currently) done on the phase only: Relative Phase Nulling. The result is a phase difference, by which the coil transmit phases are adjusted. The scanner adds the RF shim angles (centered around 0) to Coil Tx phases. Search for "TransmitPhase" in the log file to find the shim results.

Manual shimming: Scan cycled FFE. Set Multichannel images: no (not supported by RFShimGUI). Export as PARREC

single B1+ maps. dyn relative B1 maps. Single Slice.

license updates

Once a year (feb 15th) the license file expires on the scanners. Should you need to update the licenses, follow these steps (R5 specific): 1) open the Service Application 2) fill in your name and reason for entry 3) under software options, choose update license file 4) select OK

(Common) errors, malfunctions and fixes

Software

PRIDE jobs hanging

SHIMTOOL/MRCODETOOL, pride crash

• Close Application software
• run 'permproc stop ProcessingService'
• empty <G:\queue\> folder
• run 'permproc start ProcessingService'
• Restart Application software and create new examination

Hardware

No trigger

• Check if your sequence is sending triggers (sync external device ON)
• Check if sync box on console pc has power (right LED green)
• Unplug/replug power.

• table
• coldhead compressors
• gradient amplifiers

No power in bed, won't dock, no 'air puffs'

• Probably no air pressure
• Check if compressor in climate control room on office level is running (compressor located right after entrance). Pressure should be about 8 bar. Start with switch if pressure is low [picture to be uploaded]. Pressure takes minutes to build up.
• Check meters in cabinet at the back of CDAS (how to remove panel? Ask Cor/Anton).
• Pressure meters should look approx. like this: [picture to be uploaded]

No physiologic signals being logged

• Check if all sensors are plugged in, at least ECG!
• Check if ECG sensor has (working) battery
• If this is OK, switch CDAS off/on (after switching off host!)

Defect in shim gradients

Irregular 'cracking noise' in scanner room. Originates from shim rack.

Not all scanner functions available

Might have an error in shim gradients (HOS error or fault, i.e. higher order shimming). For reset:

• Enter on the computer: "permproc stop scanner"
• Turn off the 3 switches (at the bottom) of the shim gradients in the technical room. Turn off in following order: Middel, Right, Left and wait a couple of seconds
• Turn on the 3 switches in reversed order
• Enter on the computer: "permproc start scanner"

Airflow in magnet bore is insufficient (typically after bi-monthly emergency power test)

Caused by the building's climate control system not rebooting, resulting in too limited airflow to the scanners. Call 88, describe the problem!

Power off and power on sequence(s)

CDAS

• exit scanner application software
• stop all processes/services: start_stop_procs.pl stop (easier than shutting down host)
• Reset CDAS: turn off green switch. Wait 5 seconds.
• Turn red switch.
• Unplug sense-cable (on top, labeled with red arrow, this will reset/enable bore light). Wait 5 seconds.
• Turn on in reverse order: red switch and green switch.
• Wait for bed-lights (top) to turn green. Now plug in the sense-cable (red arrow). This controls bore light.
• At bed console, set light to 50%.
• start all processes/services: start_stop_procs.pl start
• wait, then start application software

Main System

• A printed copy of the instructions are in right mains cabinet in technical room.

Compressors

Procedure testing/resetting compressors Helium pump: 2 small cubic devices in the far right corner. The green light on the left device should be flashing. Check messages on small LED-displays: scroll with arrow up/down buttons. Should all be OK, not ERR. Temperature of tubes should be below room temperature (i.e. cold). To reset: press OFF. You should hear it switching off. Wait, and press ON, again hearing it switching on. To hard reset: Press OFF. Wait. Turn small black switch from I to O. Wait. Turn back to I. Wait. Important: press ON to turn the compressor back on.

Patient ventilation system

Box hanging the CDAS rack. Turn off by unplugging 220V cable.

Coil-specific tips 'n tricks

Microcoils MR Coils (surface coils)

• acquire B0 not with commonly used pickup coil elements but instead the surface coil elements. The Shimtool should apply mask to area with signal only
• connect the two surface coils mixed on the two interface boxes, not one separately on each box

BOLD screen

Turn on by switching the switch in the console room to ON. Turn off after use! The visibility range in the vertical direction is from -4 to +3 on the desktop image. This means that at the top ~10% of the screen cannot be used.

Contact information

Philips contacts (?)

Cor Romeijn: 06 22489509 Anton Heijmans: 06 22491918 Maarten Versluis: 06 11386561 Philips service: 040 7001210

AMC Contacts

During office hours, contact front office on phone number 88, option 2 Regelkamer: 62900 (outside office hours) Ed de Klerk: 06-30005770 Tom Emke: 020-5662305, 06-22452389 Roelofsen: 68103

QA

QA has moved here: 7T MRI Quality assurance*