QSM Throughout the Body

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Magnetic Resonance Imaging

Background:

• Quantitative susceptibility mapping (QSM) is a technique used to study magnetic materials in biological tissues.
• While predominantly used in the brain, QSM's application is expanding to non-cranial tissues.
• QSM leverages the magnetic susceptibility of substances like iron, calcium, and collagen to create contrast in MRI.

Purpose of the Study:

• To highlight the adaptation and application of quantitative susceptibility mapping (QSM) for imaging outside the human brain.
• To address the challenges and necessary corrections for implementing QSM in body imaging.
• To showcase the diverse potential applications of body QSM in clinical and research settings.

Main Methods:

• QSM relies on the phase shifts in gradient echo MRI sequences caused by magnetic susceptibility variations.
• A critical step for body QSM is water-fat separation to correct for the confounding chemical shift of fat.
• Techniques for compensating cardiac and respiratory motion artifacts are employed to improve image quality.

Main Results:

• Successful application of body QSM requires accurate water-fat separation to isolate susceptibility effects.
• Motion compensation techniques are vital for reliable QSM in dynamic body regions.
• Body QSM has demonstrated utility in evaluating liver iron/fibrosis, cardiac blood oxygenation, myocardial hemorrhage, and more.

Conclusions:

• Quantitative susceptibility mapping (QSM) is a versatile technique adaptable for non-brain imaging.
• Water-fat separation and motion correction are crucial for accurate body QSM.
• Body QSM offers promising avenues for diagnosing and monitoring various conditions affecting organs, vasculature, and calcifications.