QSMART: Quantitative susceptibility mapping artifact reduction technique.

Area of Science:

• Medical Imaging
• Biophysics
• Neuroimaging

Background:

• Quantitative susceptibility mapping (QSM) is an advanced MRI technique for mapping tissue magnetic susceptibility from phase images.
• QSM is an ill-posed inverse problem, often plagued by streaking and banding artifacts, especially around high susceptibility sources like vasculature.
• Existing QSM methods struggle with artifact reduction, limiting accurate susceptibility quantification.

Purpose of the Study:

• To introduce QSMART, a novel post-processing pipeline designed to mitigate streaking and banding artifacts in QSM.
• To improve the accuracy and robustness of susceptibility value estimation in various biological tissues.

Main Methods:

• QSMART employs a two-stage parallel inversion process for artifact reduction.
• A Frangi filter generates a vasculature mask for separate susceptibility estimation of tissue and veins.
• Spatially dependent filtering is utilized for background field removal, integrating susceptibility estimates for the final QSM map.
• QSMART was validated against RESHARP/iLSQR and V-SHARP/iLSQR using numerical phantoms and in vivo/ex vivo multi-species MRI data.

Main Results:

• QSMART demonstrated superior suppression of phase artifacts near the cortex compared to RESHARP and V-SHARP, without causing brain edge erosion.
• The pipeline effectively reduced streaking artifacts and enhanced tissue contrast in QSM maps.
• QSMART outperformed conventional methods in artifact reduction and image quality across diverse datasets.

Conclusions:

• QSMART significantly reduces artifacts in quantitative susceptibility mapping.
• The pipeline enables more robust and accurate estimation of magnetic susceptibility values.
• QSMART holds promise for improved in vivo and ex vivo neuroimaging applications.