Noninvasive in-vivo measurement of hepatic and cardiac iron.

This study describes a new noninvasive in-vivo method of appraising human iron stores by nuclear resonance scattering (NRS). Manganese-56 is used as a source of 847 keV gamma rays which scatter resonantly from the iron in the liver and heart of patients with Cooley's anemia (thalassemia major). These patients have heavy iron overload that may lead to cardiac and other organ failure. The NRS iron quantitation of the liver compared favorably, in a linear fashion, with the iron in the liver biopsies. Above initial value, the hepatic iron correlates with the cardiac NRS signal. There is no correlation, however, between liver enzymes and degree of iron load. NRS appears to be a reliable method for measuring cardiac and hepatic iron. It may be repeated as needed to determine the effectiveness, selectivity and compliance to therapy and prognosis.