T2* magnetic resonance: iron and gold.

As a clinician, it is important to never underestimate the power of basic science to deliver new answers to old questions. At the outset of the development of magnetic resonance (MR), scientists demonstrated differences in magnetic relaxation between normal and malignant tissues that were of significant interest, although only clinically exploited later through MR spectroscopy. Some 30 years on, the fundamental magnetic properties of tissues are once again becoming more interesting in a range of diseases. The most relevant relaxation parameter is T2* (pronounced T2 star), which has the valuable property of being shortened in tissues containing particulate iron, which disturbs the local magnetic microenvironment. Although T1 and T2