<div dir="ltr">There are four potential types of the 15-orientation table of Philips.<div><br></div><div style>1) The b0 image (i.e. 0, 0, 0) could be at the beginning or second from the last. You can see images and figure out where is b0.</div>
<div style>So your table is one type and other alternative is;</div><div style><br></div><div style><p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'">0:
1.0, 0.0, 0.0</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 1:
0.0, 1.0, 0.0</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 2:
0.0, 0.0, 1.0</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 3:
-0.1789, -0.1113, -0.9776</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 4:
-0.0635, 0.3767, -0.9242</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 5:
0.710, 0.0516, -0.7015</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 6:
0.6191, -0.4385, -0.6515</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 7:
0.2424, 0.7843, -0.5710</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 8:
-0.2589, -0.6180, -0.7423</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 9:
-0.8169, 0.1697, -0.5513</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 10:
-0.8438, 0.5261, -0.1060</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 11:
-0.2626, 0.9548, -0.1389</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 12:
0.0001, 0.9689, 0.2476</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 13:
0.7453, 0.6663, 0.0242</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 14:
0.9726, 0.2317, 0.0209</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 15:
0, 0, 0</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'"> 16:
100, 100, 100</span></p><p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'">2) There is gradient overplus and non-overplus option. The one you used is "non-overplus".</span></p>
<p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'">If you used overplus in your image protocol, it should be;</span></p><p class="" style="margin-bottom:0.0001pt">0: 0, 0, 0</p>
<p class="" style="margin-bottom:0.0001pt">1: -0.500,
-0.500, -0.707</p><p class="" style="margin-bottom:0.0001pt">2: -0.500,
-0.500, 0.707</p><p class="" style="margin-bottom:0.0001pt">3: 0.707,
-0.707, 0.000</p><p class="" style="margin-bottom:0.0001pt">4: -0.110,
-0.707, -0.699</p><p class="" style="margin-bottom:0.0001pt">5: 0.289,
-0.700, -0.653</p><p class="" style="margin-bottom:0.0001pt">6: 0.627,
-0.331, -0.705</p><p class="" style="margin-bottom:0.0001pt">7: 0.657,
-0.273, -0.702</p><p class="" style="margin-bottom:0.0001pt">8: -0.673,
-0.542, -0.504</p><p class="" style="margin-bottom:0.0001pt">9: 0.704,
-0.491, 0.513</p><p class="" style="margin-bottom:0.0001pt">10: -0.693,
-0.253, 0.675</p><p class="" style="margin-bottom:0.0001pt">11: -0.707,
-0.707, 0.028</p><p class="" style="margin-bottom:0.0001pt">12: -0.282,
-0.707, 0.648</p><p class="" style="margin-bottom:0.0001pt">13: 0.289,
-0.702, 0.651</p><p class="" style="margin-bottom:0.0001pt">14: 0.706,
-0.706, 0.054</p><p class="" style="margin-bottom:0.0001pt">15: 0.701,
-0.205, 0.683</p><p class="" style="margin-bottom:0.0001pt">
</p><p class="" style="margin-bottom:0.0001pt">16: 100,
100, 100</p><p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'">Again, you have alternative choice of b0 at the second from the last.</span></p><p class="" style="margin-bottom:0.0001pt">
<span style="font-size:10pt;font-family:'Courier New'"><br></span></p><p class="" style="margin-bottom:0.0001pt"><span style="font-size:10pt;font-family:'Courier New'">If you find out that you used the "overplus" option, you have to be very careful because you have to perform gradient re-calculation if you used oblique imaging. For example, if you do plain axial imaging, you are fine. However, if you tilted the axial plane to adjust the head orientation, the gradient table has to be also tilted. If you used "non-overplus", this table reorientation is performed on-the-fly but that's not the case for the overplus. So, stay away from overplus.</span></p>
</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Jul 4, 2013 at 1:23 AM, 罗璐娇 <span dir="ltr"><<a href="mailto:lujiaoluo1990@126.com" target="_blank">lujiaoluo1990@126.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="line-height:1.7;font-size:14px;font-family:arial">Hello experts,<div>I was using dti studio to process my diffusion data obtained from Philips <span style="font-family:微软雅黑;line-height:normal;text-align:-webkit-auto">AcHieva 1.5 T scanner(</span><span style="font-family:微软雅黑;line-height:normal">medium angular, </span><span style="font-family:微软雅黑;line-height:normal;text-align:-webkit-auto">format: DICOM, in total of 17 images) .</span></div>
<div><br></div><div><span style="font-family:微软雅黑;line-height:normal;text-align:-webkit-auto">I used the pre-defined gradient table in dti studio listed below, while plus the 16th line to exclude the last average image</span></div>
<div><span style="font-family:微软雅黑;line-height:normal;text-align:-webkit-auto"><div>0: 0, 0, 0</div><div>1: 1.0, 0.0, 0.0</div><div>2: 0.0, 1.0, 0.0</div><div>3: 0.0, 0.0, 1.0</div><div>4: -0.1789, -0.1113, -0.9776</div>
<div>5: -0.0635, 0.3767, -0.9242</div><div>6: 0.710, 0.0516, -0.7015</div><div>7: 0.6191, -0.4385, -0.6515</div><div>8: 0.2424, 0.7843, -0.5710</div><div>9: -0.2589, -0.6180, -0.7423</div><div>10: -0.8169, 0.1697, -0.5513</div>
<div>11: -0.8438, 0.5261, -0.1060</div><div>12: -0.2626, 0.9548, -0.1389</div><div>13: 0.0001, 0.9689, 0.2476</div><div>14: 0.7453, 0.6663, 0.0242</div><div>15: 0.9726, 0.2317, 0.0209</div><div>16: 100 100 100</div>
<div><br></div><div>But resulting images were not that fine, and couldn't distinguish the fiber orientations clearly. I tried to use mricron (dcm2niigue.exe) to obtain the bvecs and bvals file. But it also doesn't work. </div>
<div>Would you please tell me how to solve this problem?</div><div><br></div><div>Thanks so much!</div></span></div></div><br><br><span title="neteasefooter"><span></span></span><br>_______________________________________________<br>
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