The purpose of this study was to determine the diagnostic value of the superparamagnetic
iron oxide NSR 0430 for the detection of focal liver lesions in the presence of advanced
cirrhosis.
Cirrhosis and growth of cholangiofibromas were induced in 22 rats by administration of
thioacetamide. Sixteen non-cirrhotic animals served as controls. T1 and T2 relaxation times of liver and
tumor tissue of 12 animals were measured spectroscopically. In 10 animals in vivo MRI was performed before and 1 hour after contrast administration, and then the
tumor-to-liver contrast-to-noise ratio (CNR) was calculated. All specimens were evaluated histologically. After contrast administration, T1 and T2 values of liver tissue showed a significant decrease of 18% (P = 0.01) and 31% (P = 0.009), respectively, whereas relaxation times of
tumor tissue did not change. On precontrast turbo spin-echo images, 40
tumors could be identified; after contrast administration, 95 lesions were visible. CNR increased significantly after contrast administration by 297% at a TE of 50 msec and by 254% at a TE of 90 msec. In conclusion, our in vitro and in vivo results demonstrate that administration of
NSR 0430 substantially improves liver-to-
tumor CNR and lesion detection on T2-weighted magnetic resonance images even in the presence of severe
cirrhosis.