Iron can be measured in the heart from a small sample of the tissue obtained from a biopsy. However, most patients do not find this procedure acceptable. In addition, the distribution of iron in the heart is heterogeneous and the iron measured in a biopsy sample may not represent the total heart iron content. A non-invasive measure is magnetic resonance imaging (MRI), which is a technique that has recently been enhanced so that it can estimate the extent of iron loading in a patient’s heart. MRI tests have been used more frequently to look at iron loading in patient’s hearts. These tests provide researchers and physicians with a tool that allows them to measure the effect that an iron chelator has on the iron levels in the heart. A recent study using MRI has shown that patients treated with Ferriprox® have low levels of iron in the heart (Anderson, 2002).