Dual-contrast MR imaging of liver cancer in rats

Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02114.

MR contrast agents increase hepatic tumor conspicuity, as measured in terms of contrast-to-noise (C/N) ratios. With an animal model of hepatic metastases from breast cancer, IV administration of Gd-DTPA (0.2 mmol/kg) shows a biphasic time response, transiently increasing the signal intensity of liver relative to tumor, with C/N ratio magnitudes increasing from -5.7 to -16.3 (SE 250/20); after a delay, the signal intensity of tumor increases relative to liver with a reversal of the C/N sign from negative to positive and an increase in the C/N magnitude to +25.0. IV administration of ferrite particles (0.05 mmol Fe/kg) shows a monophasic time response, increasing signal intensity of tumor relative to liver from +1.5 to +49.5 (SE 500/30). When both contrast agents were administered together (dual-contrast technique), the tumor-liver C/N magnitude reached a maximum of +67.8 (SE 500/30) 12 min after drug infusion. Analysis of individual contrast and noise factors contributing to this technique revealed a strong correlation between the signal intensity of liver and the signal intensity of ghost artifacts, which increase after administration of Gd-DTPA (r = .89) and decrease after administration of ferrite (r = 1.0). Dual-contrast imaging shows a synergistic addition of contrast and suppression of noise from ghost artifacts, maximizing the C/N and increasing the conspicuity of focal liver lesions.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				R. F. Hanna, D. A. Aguirre, N. Kased, S. C. Emery, M. R. Peterson, and C. B. Sirlin Cirrhosis-associated Hepatocellular Nodules: Correlation of Histopathologic and MR Imaging Features RadioGraphics, May 1, 2008; 28(3): 747 - 769. [Abstract] [Full Text] [PDF]