title: Imaging of iron.
abstract: Magnetic resonance imaging (MRI) enables a noninvasive in vivo quantification of iron in various organs. Several techniques have been developed that detect signal alterations derived mainly from the magnetic properties of ferritin and hemosiderin, the major iron storage compounds. High magnetic susceptibility of ferritin shortens the transversal relaxation time of nearby water protons and thus induces a focal signal extinction of iron-rich areas in T2-weighted (T2w) MRI. T2w tissue contrast is additionally influenced by other factors such as water content, myelin density, and the presence of other metals. Therefore, more specific methods are needed with higher specificity to iron. These in vivo techniques can be divided into three groups: relaxometry, magnetic field correlation imaging and phase-based contrast covering susceptibility-weighted imaging, and quantitative susceptibility mapping. The differential diagnosis of various neurological disorders is aided by characteristic patterns of iron depositions. Reliable estimates of cerebral tissue iron concentration are equally important in studying physiological age-related as well as pathological conditions in neurodegenerative, neuroinflammatory, and vascular diseases. In the future, monitoring changes in iron storage and content may serve as sensitive biomarker for diagnosis as well as treatment monitoring.
authors.affiliation: Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic; Institut für interventionelle und diagnostische Neuroradiologie, Universitätsmedizin Göttingen, Göttingen, Germany. Electronic address: pdusek@gmail.com.
authors.forename: Petr
authors.initials: P
authors.lastname: Dusek
authors.forename: Monika
authors.initials: M
authors.lastname: Dezortova
authors.forename: Jens
authors.initials: J
authors.lastname: Wuerfel
mesh_terms: D001921:Brain / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D009410:Nerve Degeneration / Q000378:metabolism*; D019636:Neurodegenerative Diseases / Q000378:metabolism*
chemical_list: D007501:Iron
keywords: Chelating agents; Iron; MRI; NBIA; Neurodegeneration; Relaxometry; SWI