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Sepia QSM

Pipeline for processing Quantitative Susceptibility Mapping (QSM) data using the SEPIA toolbox.

__init__

Sepia 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
sepia_toolbox_path str

Path to the SEPIA toolbox. If None, assumes SEPIA is in MATLAB path.

None
reverse_phase int

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

0

A more detailed description:

This pipeline is deprecated. Please use the new QSM pipeline instead.

This pipeline contains the processing steps to compute Quantitative Susceptibility Mapping (QSM) from multi-echo gradient echo (GRE) data using the SEPIA toolbox. It is used in our paper:

[1] Wang Y, Ye C, Pan R, Tang B, Li C, Liu J, Tao W, Zhang X, Yang T, Yan Y, Jiang S, Lui S, Wu B. Cognitive implications and associated transcriptomic signatures of distinct regional iron depositions in cerebral small vessel disease. Alzheimers Dement. 2025 Apr;21(4):e70196. doi: 10.1002/alz.70196. PMID: 40257048; PMCID: PMC12010275.