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QSM Pipeline

QSM Processing Pipeline using Sepia and QQNet.

__init__

QSM processing pipeline.

Parameters:

Name Type Description Default
subject BIDSSubject

A BIDS subject object.

required
session BIDSSession

A BIDS session object.

required
output_path str

Output directory to save results.

required
use_which_t1w str

Keyword to select the desired T1w image.

None
normalize bool

If True, normalize QSM (and other scalar maps) to MNI space via T1w.

False
phase_image_correction bool

If True, apply phase image correction for inter-slice phase polarity differences in the GE data. (https://github.com/kschan0214/sepia/discussions/93)

False
reverse_phase int

Set to 1 to inverse phase polarity (for GE scanners).

0

A more detailed description:

This pipeline contains the processing steps to compute Quantitative Susceptibility Mapping (QSM) and other scalar maps from multi-echo gradient echo (GRE) data by the following steps:

  1. QSM reconstruction using a combined approach from the SEPIA toolbox and Chisep toolbox, including:
    • Phase unwrapping (SEPIA: ROMEO total field calculation)
    • Background field removal using V-SHARP (SEPIA)
    • Dipole inversion using iLSQR (Chisep)