Synopsis

Keywords: Contrast mechanisms: Susceptibility, Contrast mechanisms: Relaxometry, Neuro: Brain

The basics of SWI, QSM and R₂^* will be introduced along with the contrast mechanisms for iron imaging. Sensitivity, specificity and limitations will be illustrated as well as examples for iron imaging in neurologic disorders.

Susceptibility is a measure of how much a material gets magnetized in an external magnetic field. Paramagnetic materials have unpaired electrons and paramagnetism is temperature dependent. QSM differentiates between para- and diamagnetic materials. R₂^* relaxometry is sensitive to both iron and myelin. QSM and SWI can differentiate MS lesion types. QSM and R₂^* quantify age- and pathology related iron accumulation in brain nuclei and cortices.