Hi,
In eddy_correct FLIRT is used to register the b volumes to
the B0 volume. As already described in an earlier post,
I frequently notice a scaling, see output of avscale for the
derived affine transformations for one of the b volumes:
Rotation & Translation Matrix:
0.999991 -0.003124 -0.002873 -1.394440
0.003120 0.999994 -0.001635 -3.587220
0.002878 0.001626 0.999995 -1.920300
0.000000 0.000000 0.000000 1.000000
Scales (x,y,z) = 1.018279 1.039003 1.017240
Skews (xy,xz,yz) = -0.001957 -0.001985 -0.005259
Average scaling = 1.02484
Determinant = 1.07623
Left-Right orientation: preserved
Forward half transform =
1.009096 -0.002589 -0.002446 -0.697537
0.001575 1.019312 -0.003477 -1.777544
0.001452 0.000828 1.008578 -0.954807
0.000000 0.000000 0.000000 1.000000
Backward half transform =
0.990976 0.002540 0.002411 0.698059
-0.001524 0.981047 0.003344 1.745984
-0.001426 -0.000816 0.991492 0.944238
0.000000 0.000000 0.000000 1.000000
I would like to remove the scaling from the matrix.
How to proceed?
Ed
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