How to Restore the shim to standard 'Head' values

• Use this procedure if the shim is bad and not converging. This should also be run after each study of an object other than a human head.
• Be sure that the grad shim has been set to 0 for X, Y and Z before your begin.

1. From the instascan console, open a window and start the shimmer program.
2. Select option 5 (more options)
3. Select option 6 (read settings from a file)
4. Enter in a file name. A good starting file is:

   /usr/export/home/anmr/stdhead

5. After the file is loaded, select 7 (return to basic options)

A screen capture of this process appears below. User entries appear in boldface:

instascan# shimmer e--------------------------------------------------------------------------e | shimmer_r6 is a user-friendly interface for the suite of programs that | | enable automated shimming on the Signa-Instascan systems. shimmer_r6 | | was written by Tim Reese (me, the author). The programs it runs were | | developed by Tim Davis (xds, WU), David Harrison (xgraph, UCB) and me, | | with collaborative help from Robert Weisskoff. Please address questions, | | change requests or bug reports to Tim Reese, reese@nmr.MGH.harvard.edu. | e--------------------------------------------------------------------------e ----------- checking Resonance Research shim power supply---------------- opening serial port. activating controller DAC. controller power is currently on. closing serial port. WARNING --- shimmer:depthfirst_pwd:directory error at file .apdconfig:no such file or directory -------------------------------------------------------------------------- X : -0.046144 ZX : 0.170049 Y : 0.140873 ZY : 1.197668 Z : 0.767724 XY : 0.077517 Z2 : -0.819727 X2Y2 : -0.257942 -------------------------------------------------------------------------- CURRENT PARAMETERS: Bay 2 Signa/Instascan, through 2nd order columns, rows and slices: 128,64,9 voxel dimensions in mm: 3.2,3.2,10 Echo shift: 4.4 ms, Acquisition time: 32 ms orientation: axial, I-S slice, R-L read, supine current directory: /home/anmr (no I/Q images found) SHIM PROCESSING OPTIONS (TOP LEVEL MENU) 0) go process image data 1) <inactive> 2) <inactive> 3) start the manual shim controller 4) select a shim volume? no 5) more options 6) quit (0 to 6, 0) :: 5 SHIM PARAMETER OPTIONS (SECOND LEVEL MENU) 0) pick shims to evaluate : Z0,Z1,X1,Y1,Z2,ZX,ZY,XY,X2Y2 1) enable cardiac mode? no (in development) 2) display correlations? no (in development) 3) change magnitude threshold from 10% 4) enable DUMP in shimfit? no 5) save shim settings to a file. 6) read shim settings from a file. 7) return to basic options (0 to 7, 7) :: 6 Enter the file name to restore from (must be the full path!) default: /tmp/shim_settings4029 :: /usr/export/home/anmr/stdhead opening serial port. closing serial port. shimcontrol_r2: shim settings restored from file /usr/export/home/anmr/stdhead SHIM PARAMETER OPTIONS (SECOND LEVEL MENU) 0) pick shims to evaluate : Z0,Z1,X1,Y1,Z2,ZX,ZY,XY,X2Y2 1) enable cardiac mode? no (in development) 2) display correlations? no (in development) 3) change magnitude threshold from 10% 4) enable DUMP in shimfit? no 5) save shim settings to a file. 6) read shim settings from a file. 7) return to basic options (0 to 7, 7) :: 7