Ferrite, a new magnetic resonance (MR)
contrast agent, was evaluated in the detection and diagnosis of splenic
lymphoma. Before administration of
ferrite, normal rat spleens and spleens with
diffuse lymphoma showed similar in vitro relaxation times and in vivo MR imaging signal-to-noise ratios (S/N). After the administration of
ferrite (50 mumol Fe/kg), the T2 time of lymphomatous spleen was 27.0 msec +/- 2.9 (mean +/- standard deviation), which was significantly greater than that of normal spleen (10.7 msec +/- 1.5, P less than .005). The S/N of
ferrite-enhanced in vivo MR images of lymphomatous spleen was 12.4 +/- 0.9, which was significantly greater than normal (5.7 +/- 0.2, P less than .005). Similar experiments with animal models of micronodular
lymphoma also demonstrated that
ferrite-enhanced MR imaging can distinguish micronodular
lymphoma from normal spleen. Benign
splenomegaly, studied with an animal model of erythroid
hyperplasia, showed
ferrite-enhanced MR tissue characteristics that were indistinguishable from those of normal spleen.