<div dir="ltr">Thanks a lot.<br><br>Seongjin<br><br><div class="gmail_quote">On Fri, Jul 25, 2008 at 7:12 AM, susumu <<a href="mailto:susumu@mri.jhu.edu">susumu@mri.jhu.edu</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-US">
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<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">Seongjin,</span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">In Philips, there are 3 types (low: 6,
medium: 15, high: 32) x 2 (overplus on/off) = 6 gradient tables.</span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">The "gradient overplus = on"
always use at least two gradients to enhance b efficiency and therefore gaining
several millisecond of echo time. In your example, the low and high is
"overplus = off" and the medium is "overplus = on". You can
see "1, 0, 0" in the first two but not in the medium. </span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">The medium with "overplus = off"
should look like;</span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 0:
0, 0, 0</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 1:
1, 0, 0</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 2:
0, 1, 0</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 3:
0, 0, 1</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 4:
-0.0424,-0.1146,-0.9925 </span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 5:
0.1749,-0.2005,-0.9639</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 6:
0.2323,-0.1626,-0.9590</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 7:
0.3675,0.0261,-0.9296 </span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 8:
0.1902,0.3744,-0.9076</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 9:
-0.1168,0.8334,-0.5402 </span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 10:
-0.2005,0.2527,-0.9466</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 11:
-0.4958,0.1345,-0.8580</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 12:
-0.0141,-0.6281,-0.7780</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 13:
-0.7445,-0.1477,-0.6511</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 14:
-0.7609,0.3204,-0.5643</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 15:
-0.1809,0.9247,-0.33510</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 16:
-0.6796,-0.4224,-0.5997</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 17:
0.7771,0.4707,-0.4178</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 18:
0.9242,-0.1036,-0.3677</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 19:
0.4685,-0.7674,-0.4378</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 20:
0.8817,-0.1893,-0.4322</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 21:
0.6904,0.7062,-0.1569</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 22:
0.2391,0.7571,-0.6080</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 23:
-0.0578,0.9837,0.1703</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 24:
-0.5368,0.8361,-0.1135</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 25:
-0.9918,-0.1207,-0.0423</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 26:
-0.9968,0.0709,-0.0379</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 27:
-0.8724,0.4781,-0.1014</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 28:
-0.2487,0.9335,0.2581</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 29:
0.1183,0.9919,-0.0471</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 30:
0.3376,0.8415,0.4218</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 31:
0.5286,0.8409,0.1163</span></font></p>
<p style=""><font size="2" face="Courier New"><span style="font-size: 10pt;"> 32:
0.9969,0.0550,-0.0571</span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">In general, I do not recommend to user
"overplus = on", because tensor calculation get complicated when
oblique planes are used. You have to recalculate the table based on the image
angles.</span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">Also, please note that the "0, 0,
0" could be the first or the last image depending on how you specify the
output files.</span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">Susumu</span></font></p>
<p><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;"> </span></font></p>
<div>
<div style="text-align: center;" align="center"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">
<hr size="2" width="100%" align="center">
</span></font></div>
<p><b><font size="2" face="Tahoma"><span style="font-size: 10pt; font-family: Tahoma; font-weight: bold;">From:</span></font></b><font size="2" face="Tahoma"><span style="font-size: 10pt; font-family: Tahoma;">
<a href="mailto:mristudio-users-bounces@mristudio.org" target="_blank">mristudio-users-bounces@mristudio.org</a>
[mailto:<a href="mailto:mristudio-users-bounces@mristudio.org" target="_blank">mristudio-users-bounces@mristudio.org</a>] <b><span style="font-weight: bold;">On Behalf Of </span></b>[Seongjin]<br>
<b><span style="font-weight: bold;">Sent:</span></b> Wednesday, July 23, 2008
3:47 PM<br>
<b><span style="font-weight: bold;">To:</span></b> DTI Studio, ROI Editor,
Landmarker Questions/Support<br>
<b><span style="font-weight: bold;">Subject:</span></b> [Mristudio-users] Philips
gradient tables</span></font></p>
</div><div><div></div><div class="Wj3C7c">
<p><font size="3" face="Times New Roman"><span style="font-size: 12pt;"> </span></font></p>
<div>
<p><font size="3" face="Times New Roman"><span style="font-size: 12pt;">Dear DTIstudio users,<br>
<br>
I wonder if you have gradient tables for Philips Achieva system.<br>
<br>
>From a source I have a gradient table for low resolution as follows:<br>
<br>
0:1.0000, 0.0000, 0.0000<br>
1:0.0000, 1.0000, 0.0000<br>
2:0.0000, 0.0000, 1.0000<br>
3:-0.7044, -0.0881, -0.7044<br>
4:0.7044, 0.7044, 0.0881<br>
5:0.0881, 0.7044, 0.7044<br>
6:0.0000, 0.0000, 0.0000<br>
<br>
<br>
For medium,<br>
<br>
0: 0.7071 -0.7071 1.00<br>
1: 0.7071 -0.7071 -1.00<br>
2: 1.0000 1.0000 0.0000<br>
3: 0.9999 -0.1561 0.9879<br>
4: 0.9894 0.4091 0.9240<br>
5: 0.4674 0.8874 0.9970<br>
6: 0.3866 0.9297 0.9930<br>
7: 0.7667 -0.9511 0.7124<br>
8: 0.6945 0.9954 -0.7295<br>
9: 0.3580 -0.9800 -0.9547<br>
10: 1.0000 -0.9992 -0.0392<br>
11: 0.9999 -0.3989 -0.9171<br>
12: 0.9923 0.4082 -0.9213<br>
13: 0.9989 0.9982 -0.0759<br>
14: 0.2899 0.9919 -0.9655<br>
15: 0.0000 0.0000 0.0000<br>
<br>
<br>
For high,<br>
<br>
0: 1.000, 0.000, 0.000<br>
1: 0.000, 1.000, 0.000<br>
2: 0.000, 0.000, 1.000<br>
3: -0.042, -0.115, -0.993<br>
4: 0.175, -0.200, -0.964<br>
5: 0.232, -0.163, -0.959<br>
6: 0.368, 0.026, -0.930<br>
7: 0.190, 0.374, -0.908<br>
8: -0.117, 0.833, -0.540<br>
9: -0.200, 0.253, -0.947<br>
10: -0.496, 0.134, -0.858<br>
11: -0.014, -0.628, -0.778<br>
12: -0.744, -0.148, -0.651<br>
13: -0.761, 0.320, -0.564<br>
14: -0.181, 0.925, -0.335<br>
15: -0.680, -0.422, -0.600<br>
16: 0.777, 0.471, -0.418<br>
17: 0.924, -0.104, -0.368<br>
18: 0.468, -0.767, -0.438<br>
19: 0.882, -0.189, -0.432<br>
20: 0.690, 0.706, -0.157<br>
21: 0.239, 0.757, -0.608<br>
22: -0.058, 0.984, 0.170<br>
23: -0.537, 0.836, -0.113<br>
24: -0.992, -0.121, -0.042<br>
25: -0.997, 0.071, -0.038<br>
26: -0.872, 0.478, -0.101<br>
27: -0.249, 0.933, 0.258<br>
28: 0.118, 0.992, -0.047<br>
29: 0.338, 0.841, 0.422<br>
30: 0.529, 0.841, 0.116<br>
31: 0.997, 0.055, -0.057<br>
32: 0.000, 0.000, 0.000<br>
<br>
<br>
I wonder if the tables above are correct or not. Is there anything incorrect or
partially incomplete, please let me know.<br>
Thanks in advance.<br>
<br>
Sincerely,<br>
Seongjin </span></font></p>
</div>
</div></div></div>
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