JeffFessler / JeffFessler/mirt

mri_field_map_reg_scale causing bright pixels outside head

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Dominant language
MATLAB
Stars
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Forks
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Description

MH reports that putting images from J-SENSE recon code output
https://sigpy.readthedocs.io/en/latest/generated/sigpy.mri.app.JsenseRecon.html#sigpy.mri.app.JsenseRecon
into mri_field_map_reg.m causes amplification of pixels outside the head in this line:

https://github.com/JeffFessler/mirt/blob/43b20b5ea04b5bb61979aea7574ca73e3ea1b291/mri/fieldmap/mri_field_map_reg.m#L96
https://github.com/JeffFessler/mirt/blob/43b20b5ea04b5bb61979aea7574ca73e3ea1b291/mri/fieldmap/mri_field_map_reg.m#L148

Masking the fieldmaps (using ESPIRT masks) addressed the issue.
Fixing this is a low priority because I recommend using this code instead anyway:
https://github.com/ClaireYLin/regularized-field-map-estimation

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with mri/fieldmap/mri_field_map_reg.m at the referenced lines and reproduce the behavior using images from sigpy's JsenseRecon output. Compare the result with ESPIRT-masked fieldmaps; done means the reconstruction no longer amplifies pixels outside the head without requiring that masking workaround.

Written by the indexing model from the issue text.

Assessment

Tech stack
matlab
Domain
computer-vision
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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