Noninvasive quantitation of liver iron in dogs with hemochromatosis using dual-energy CT scanning.

The concentration of iron deposited in the livers of two dogs with experimentally induced iron overload was determined by use of dual energy computerized tomographic (CT) scanning. A phantom was constructed, containing known amounts of iron-dextran solutions. CT scans of the phantoms, at 80 and 120 kVp, corrected for the response of water, showed a linear relationship between known iron concentrations and difference in CT number at the two scanning energies, with a change of 24 H units per 1000 mg% iron. Using the graph of this linear relationship, the amount of iron in dog liver was predicted, compared with the amount of iron measured from biopsy specimens, and analyzed by neutron activation analysis. A close correlation existed between predicted liver iron and measured iron concentration (r = 0.99). Dual-energy CT scanning appears to provide an accurate, noninvasive method of quantitating liver iron.