[Mristudio-users] error when calculating tensor with double gradient table

Fri Jul 11 21:55:56 EDT 2008

Hi Elizabeth,

There could be some bug. I must admit that we haven't rigorously tested the
AIR-realigned table. In general if tensor calculation crushes after
successful loading, following should be considered.

1)       memory issue: Please try partial slice calculation (e.g. calculate
only slice 1-20 instead of all slices).

2)       Gradient table issue: Please load the data once, make sure that all
images are loaded, close the window, and do "DTI Mapping" again. In the data
input window, inspect the b-table, which is remember from the previous
processing. If there is any mistake in the syntax, you can see how DtiStudio
interpreted the table.

3)       Also try no auto rejection and see if it works. Auto rejection is
still a beta version.

Please let us know the results of these tests.

Susumu

  _____  

From: mristudio-users-bounces at mristudio.org
[mailto:mristudio-users-bounces at mristudio.org] On Behalf Of [Seongjin]
Sent: Wednesday, July 09, 2008 4:40 PM
To: DTI Studio, ROI Editor, Landmarker Questions/Support
Subject: Re: [Mristudio-users] error when calculating tensor with double
gradient table

Dear Elizabeth,

What vendor is this table for?

Best,

Seongjin Choi

On Wed, Jul 9, 2008 at 3:39 PM, Elizabeth Finger
<Elizabeth.Finger at lhsc.on.ca> wrote:

Hello-

I have running into an error- the DTI Mapping program is crashing out, when
attempting to do a tensor calculation with an updated gradient table from
the AIR Matrix calcuation that uses two series.  We have two separate series
with 3 b0 images and 33 graidents with the same DTI parameters per subject.
We have used AIR to align them together, and generated an updated gradient
table. When we reload the two AIR series into the DTI Mapping window with
the new gradient table from AIRMatrix output (table pasted below, now with
72 lines, starting w/ 0 and ending w/ 71), the data load correctly. However,
when we attempt to run the tensor calculation with automatic outlier
rejection, as soon as the calculation starts the program crashes out.  If we
use the original gradient table there is no problem. Also, if we use half of
the updated gradient tables (either first half w/ numbers from 0 to 35, or
the second half w/ original airmatrix numbers from 36-71, the tensor
calculation works. Is there something else we can do to use the revised
gradient table for both series and include both series in the tensor
calculation?

Thank you,
Elizabeth Finger

***   New Gradient Table   ***
 0: 0.000000, 0.000000, 0.000000
 1: 0.000000, 0.000000, 0.000000
 2: 0.000000, 0.000000, 0.000000
 3: 0.999999, 0.000434, -0.000390
 4: 0.313706, 0.949767, -0.000230
 5: -0.072833, 0.636259, 0.767252
 6: 0.875411, -0.479757, 0.061399
 7: -0.199675, -0.555806, 0.809540
 8: -0.615266, -0.363411, 0.700719
 9: 0.684460, 0.371145, 0.627016
10: -0.565897, 0.821968, 0.063204
11: 0.901326, 0.406546, 0.148179
12: 0.093208, -0.995034, -0.035177
13: 0.144608, -0.895242, -0.421890
14: 0.524194, -0.680821, -0.509454
15: -0.481128, -0.733741, 0.480656
16: -0.823076, 0.449965, 0.347979
17: -0.888253, -0.063133, -0.455690
18: -0.672102, -0.732741, 0.110781
19: 0.699453, -0.110723, -0.705987
20: 0.441389, -0.391523, -0.806244
21: -0.281831, -0.814184, -0.507885
22: -0.601632, -0.812283, -0.508305
23: 0.629421, 0.708171, 0.317496
24: -0.568210, 0.273148, -0.778529
25: 0.829784, -0.324714, 0.454091
26: 0.313490, 0.491775, 0.811144
27: 0.054139, -0.216170, -0.975053
28: 0.286972, -0.904461, 0.315101
29: 0.923529, -0.021970, -0.383806
30: 0.264165, -0.607207, 0.749858
31: 0.260233, -0.609104, 0.749834
32: 0.854475, 0.400779, -0.330854
33: -0.097884, 0.220989, -0.970907
34: -0.349784, -0.104215, 0.931861
35: -0.426056, -0.091100, -0.900897
36: 0.000000, 0.000000, 0.000000
37: 0.000000, 0.000000, 0.000000
38: 0.000000, 0.000000, 0.000000
39: 0.999991, -0.004224, -0.000249
40: 0.314415, 0.949532, -0.000519
41: -0.075562, 0.638964, 0.766869
42: 0.875203, -0.479650, 0.061976
43: -0.199274, -0.552859, 0.809863
44: -0.614361, -0.360801, 0.701046
45: 0.685615, 0.369276, 0.626992
46: -0.559605, 0.826597, 0.062539
47: 0.904448, 0.399873, 0.148048
48: 0.093181, -0.995075, -0.035007
49: 0.144334, -0.895057, -0.421964
50: 0.519135, -0.685870, -0.509212
51: -0.481587, -0.732226, 0.480938
52: -0.823207, 0.450559, 0.347815
53: -0.886639, -0.063294, -0.456166
54: -0.676109, -0.728467, 0.111361
55: 0.700883, -0.109309, -0.705804
56: 0.444573, -0.392454, -0.805908
57: -0.280834, -0.812282, -0.508434
58: -0.601365, -0.814664, -0.507772
59: 0.629210, 0.711182, 0.316532
60: -0.566986, 0.272640, -0.778692
61: 0.830525, -0.326559, 0.453683
62: 0.315200, 0.490945, 0.811119
63: 0.054672, -0.213494, -0.975138
64: 0.284283, -0.905688, 0.314935
65: 0.923751, -0.020852, -0.383734
66: 0.259252, -0.608233, 0.749993
67: 0.259508, -0.605161, 0.750359
68: 0.854059, 0.401502, -0.330884
69: -0.095633, 0.224934, -0.970803
70: -0.349293, -0.104589, 0.931882
71: -0.423139, -0.088227, -0.901151

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