7T QA

Run 7T QA on Classic R5.

FID QA measurements

This procedure repeatedly measures the 8th sample of a pulse-acquire FID measurement, using proton and multi-nuclei amplifiers, with and without gradients. Creator: Paul Sanders, Philips

Logbook

20161011 MC: MN with gradients 3rd channel: spurious spikes of 1%

Scanning procedure

• Position blue phantom sphere in center of 32ch head coil, use holder. Make sure the phantom is centered.
• Remove any installed patch
  • The application software might not show that there is a patch active, but if the 'G:\Patch\' folder contains files, there is a patch installed.
  • Open SmartPatch and press 1. This will take a while.

• Go to ´G:\Toolbox_TestPlatform´, and double click ´start_MR_signal_stability_mtx2_v1.bat´ to start scanning. A command window appears, and the phantom positioning wordt gedaan. Deze mag maximaal 10% afwijken. Als het phantoom goed ligt, klik op enter om de QA te beginnen.
• After 2 minutes, turn on patient communication to verify that you here repeating 'ticks'.
• Scanning finishes after ~20 minutes. In command window it says: 'press any key to continue'. Click space bar, this ends the measurement.

Als de phantoom positionering het niet doet:

• Start scan software
• Perform a prescan : QA\QA_FID_Survey
  • Scan a survey. Click OK on the following message: 'Cannot determine optimum RF power'.
• Application software can be on, but list of planned scans must be empty.

PlotServer (appear during scanning)

• Tab1 Mod profile: shows FID for all measurements
• Other tabs plot the repeated 8th sample of FID for all 32 channels. Horizontal axis: repeated measure (512 or 1024). 150ms between measurements.
  • measurement 250-275: programmed 1% lower signal as a reference
  • first 16: box A (lower). last 16: box B. (border between magenta/purple and cyan/lightblue)
  • Gr=true/false: gradients on/off. MN (multi-nuclei) or PR (proton) amplifier.

Save output

• ZIP folder G:\Toolbox_TestPlatform\TestData\mtx2_mr_signal_stab\7t_acq_DATE and copy to S:\7T_QA\FID (\\ftpsc\DATA\scdropbox\7T_QA\FID)

Offline processing

Update weekly after QA

Project folder: \\ftpsc\DATA\scdropbox\7T_QA\FID To make QA plots: fid_batch_run_7T.m

Summary plots

Output files of the batch run script appear here: \\ftpsc\Projects\7TQA\fidstab_results

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MN = Multi Nuclei Amplifier PR = Proton Amplifier GR0 = No Gradient GR1 = With Gradient

Image shows the standard deviation of four channels (8,12,31,32) over time.

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Individual plots of each channel. axis are the same in the previous figure.

Individual plots

\\ftpsc\Projects\7TQA\fidstab\7t-acq_20180509\fig_5_MN_sc_fid_v4_stab_no_grad_2_tx1_tr_vol_20180509160953.png

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Start MATLAB and run matlab-script scdropbox/7T_QA/FID/software/fid/fid_stab_viewer_v4.m. A file prompt appears, open one .txt file in the output folder. Now all plots for all output-files in this directory are generated.

FID software details

• software is installed in G:\TA (Ruby language, .rb files)
• double click G:\TA\Ruby193\start_ruby193*.bat to start Ruby

• sc_fid_stability_r5_v1.rb
  • lines 21:24: (Only_grad_switching) true: run with gradient switching. false: one times without, one time with gradients.
  • Start_pr_rf_amp: first PR then MN amplifier. false: start with MN
  • repeat_per_tests --> 1024

• sc_fid_stability_r5_v1.rb
  • lines 292 pulse-acquire scan
  • 300-307: add gradient blocks (objects are removed based on only_grad_switching setting)
  • 308 RF0 RF-pulse
  • 309 AQ0 acquire FID signal

load files to view/verify:

• (drag G:\TA\Testscripts\sc_fids\start_fid_stability*.bat into Ruby window (not so interesting))

EPI Stability Tool

TO DO

- Ronde houder voor Sphere A, 5 grijze kussentjes

- patch Utrecht_w_Pride (nu #6)

- het QA protocol staat onder hospital, QA: QA20150404

- runt zelf tot de eerste DWI-EPI, even inplannen.

- shimtool gebruiken voor tweede B0.

- voor en na laatste scan in Control Parameter Editor dynamic noise scan op 'no RF GR'

- alle data exporteren als PAR/REC in dbimexp.

- move to dropbox folder 7T QA

- copy logs from E:\export\PRIDE\EPI_stability_tool fMRIstabilityoutput.txt en diffusionstabilityoutput.txt

- run readEpi and readDTI scripts in Matlab. Use _simple version for Windows (no fancy output).

Online temporal SNR measurements.