The brain has long been a major focus for QSM, while applications of QSM outside the brain have occurred more recently. This course deals with both the technical aspects specific to QSM of the body and some of its clinical applications.
To date, most of the development of quantitative susceptibility mapping (QSM) has occurred in the brain. A rich endogenous variation in susceptibility and the relative ease with which high resolution imaging can be performed has led to a proliferation of applications of QSM in both the healthy and diseased brain. Applications of QSM outside the brain have occurred more recently. This course deals with both the technical aspects specific to QSM of the body and some of the clinical applications.
Technical issues encountered when extending QSM to the body
include among others
1.
dealing with breathing and cardiac motion.
2.
presence of fat which alters the phase of the
MRI signal that is not described by the conventional dipole convolution model.
3.
presence of tissues with extremely short
transverse relaxation times making accurate field estimation more challenging.
4.
Proximity to air-tissue interfaces complicating
distinctions between local and background susceptibility sources.
Clinical applications of QSM in the body include among
others
1.
oxygenation and oxygen consumption
2.
bone and cartilage characterization
3.
iron overload assessment
4.
detecting calcifications and hemorrhage.
1. Wang, Y. & Liu, T. Quantitative susceptibility mapping (QSM): Decoding MRI data for a tissue magnetic biomarker. Magnetic resonance in medicine 73, 82-101 (2015).
2. Wang, Y. et al. Clinical Quantitative Susceptibility Mapping (QSM): Biometal Imaging and Its Emerging Roles in Patient Care. JMRI in press (2017).