QSMxT: Robust masking and artifact reduction for quantitative susceptibility mapping.

Area of Science:

• Medical Imaging
• Biophysics

Background:

• Quantitative susceptibility mapping (QSM) is crucial for estimating tissue magnetic susceptibility from MRI phase data.
• Current QSM masking techniques suffer from artifacts, exclude anatomical information, and require extensive parameter tuning and anatomical priors.

Purpose of the Study:

• To develop a robust, automated masking and reconstruction procedure for QSM.
• To overcome limitations of existing QSM masking techniques, reducing artifacts and improving anatomical detail.
• To integrate the new procedure into an open-source software framework, QSMxT.

Main Methods:

• A novel masking technique was developed to automatically differentiate reliable from unreliable phase regions.
• A two-pass reconstruction procedure was employed, processing separated phase regions before combination.
• The method was tested across various MRI acquisitions, including 3 T and 7 T in volunteers, patients, and an in silico phantom.

Main Results:

• The two-pass inversion significantly reduced streaking artifacts compared to standard methods.
• The technique demonstrated robustness across diverse acquisition settings and phantoms.
• Substantial reductions in artifacts and errors were observed, alongside enhanced anatomical detail and minimal parameter tuning.

Conclusions:

• The developed two-pass masking and reconstruction procedure enables more accurate QSM.
• This method mitigates artifacts, operates without anatomical priors, and requires minimal parameter tuning.
• Integration into QSMxT enhances accessibility and robustness of QSM processing, particularly against streaking artifacts.