Enhanced tumor detection in the presence of liver cirrhosis: Experimental study on the diagnostic value of a superparamagnetic iron oxide MR imaging contrast agent (NSR 0430)

The purpose of this study was to determine the diagnostic value of the supe rparamagnetic iron oxide NSR 0430 for the detection of focal liver lesions in the presence of advanced cirrhosis, Cirrhosis and growth of cholangiofib romas were induced in 22 rats by administration of thioacetamide, Sixteen n on-cirrhotic animals served as controls. T1 and T2 relaxation times of live r and tumor tissue of 12 animals were measured spectroscopically. In 10 ani mals in vivo MRI was performed before and 1 hour after contrast administrat ion, and then the tumor-to-liver contrast-to-noise ratio (CNR) was calculat ed. All specimens were evaluated histologically. After contrast administrat ion, 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 t umor tissue did not change. On precontrast turbo spin-echo images, 40 tumor s could be identified; after contrast administration, 95 lesions were visib le. 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 a nd in vivo results demonstrate that administration of NSR 0430 substantiall y improves liver-to-tumor CNR and lesion detection on Ta-weighted magnetic resonance images even in the presence of severe cirrhosis. J, Magn, Reson, Imaging 1999;9:251-256. (C) 1999 Wiley-Liss, Inc.