High-Tc Susceptometer to Monitor Transfusional Iron Overload

The proposed research project will continue the application and development of a new method (biomagnetic susceptometry) that measures magnetic fields to determine how much iron is in the liver. The amount of iron in the liver is the best indicator of the amount of iron in the whole body. Measuring the amount of iron in the body is important because either too much (iron overload) or too little iron (iron deficiency) can be harmful. At present, the most reliable way to measure the amount of iron in the liver is to remove a sample of the liver by biopsy, either by surgery or by using a needle which pierces the skin and liver. Iron stored in the liver can be magnetized to a small degree when placed in a magnetic field. In patients with iron overload, the investigators previous studies have shown that magnetic measurements of liver iron in patients with iron overload are quantitatively equivalent to biochemical determinations on tissue obtained by biopsy. In the past the investigators have developed a device to measure the amount of magnetization, which was called a SQUID (Superconducting QUantum Interference Device) susceptometer. This device was validated and in use for over 20 years. The safety, ease, rapidity and comfort of magnetic measurements make frequent, serial studies technically feasible and practically acceptable to patients. The investigators have now developed a new susceptometer, which uses very similar technology to the SQUID, but the investigators believe is more accurate and precise. This study aims to validate this new instrument. The investigators will do prospective, serial studies of the diagnosis and management of patients with iron overload, including thalassemia major (Cooley's anemia), sickle cell disease, aplastic anemia, myelodysplasia, hereditary hemochromatosis, and other disorders.