This method of fMRI distortion correction is implemented in the HCP
On 5/13/18, 11:14 PM, "FSL - FMRIB's Software Library on behalf of Him
anshu" <[log in to unmask] on behalf of [log in to unmask]> wrote:
>Thank you for your response...
>I also feel that with 2X distortion scans acquired using spin echo is
>better conditioned than a standard field map. And even I din't acquired
>the regularized field map either. Therefore, I have to use 2X distortion
>scans to correct susceptibility induced distortions in my fMRI data. For
>this, I have tried FSL-topup and used the commands given below.
>Given that I have two short EPIs, each with 3 volumes (A_P and P_A) in
>anterior to posterior and posterior to anterior directions. And I need
>to correct the distortions of my resting state EPI, which have 200
>volumes and is acquired in P_A direction.
>fslroi A_P b0_blip_up 0 1
>fslroi P_A b0_blip_down 0 1
>fslmerge -t both_b0 b0_blip_up b0_blip_down
>topup --imain=both_b0 --datain=my_acq_param.txt --config=b02b0.cnf
>applytopup --imain=A_P,P_A --inindex=1,2 --datain=my_acq_param.txt
>I can anticipate that my_hifi_images have 3 volumes does not have
>susceptibility induced distortions. Kindly suggest that how the
>susceptibility induced distortions of my resting state EPI can be
>corrected using applytopup?
>Can you suggest some pointers to solve this issue/problem.
>Thanks and Regards