Kreft B, Block W, Dombrowski F, Fackeldey A, Bachmann R, Muhlhauser J, Traber F, Oksendal A, Pfeifer U, Schild HH.Diagnostic value of a superparamagnetic iron oxide in MR imaging of chronic liver disease in an animal model. AJR Am J Roentgenol 1998 Mar;170(3):661-8
OBJECTIVE: The enhancement
characteristics and the diagnostic value of a cell-specific superparamagnetic
contrast agent (NSR 0430) in different degrees of liver fibrosis
and cirrhosis were experimentally studied in an animal model.
MATERIALS AND METHODS: Chronic liver damage was induced in rats
either by oral administration of carbon tetrachloride (CCl4) for
15 weeks (n = 37) or by oral administration of thioacetamide (TAA)
in drinking water for 24-26 weeks (n = 48). Twenty-six animals
served as control subjects. T1 and T2 relaxation times for the
liver and the spleen were measured in vitro with a spectrometer
at 40 MHz. In vivo MR imaging at 1.5 T also was performed using
T2-weighted turbo spin-echo sequences before and 1 hr after administration
of NSR 0430. All data were correlated with the histologic degree
of liver fibrosis and cirrhosis and the amount of connective tissue
in the liver, which was measured morphometrically. RESULT: CCl4
produced liver fibrosis in most of the animals, and TAA predominantly
caused liver cirrhosis. NSR 0430 caused a T2 relaxation time decrease
in the control animals by 49%; in the CCl4 group with light and
moderate liver fibrosis, by 25%; in the CCl4 group with severe
liver fibrosis or cirrhosis, by 16%; and in the TAA group with
cirrhosis, by 30%. On the T2-weighted turbo spin-echo sequences,
liver signal-to-noise ratios (SNRs) decreased after contrast agent
administration in the control animals by 81% and 79%, depending
on the TE parameter. In the CCl4 group, liver SNRs decreased by
96% and 61% in animals with light or moderate fibrosis and by
44% and 55% in animals with severe fibrosis or cirrhosis, depending
on the TE parameter. In the TAA group, liver SNR decreased by
61% and 67%, depending on the TE parameter. CONCLUSION: Enhancement
of the superparamagnetic contrast agent NSR 0430 is decreased
in the presence of liver fibrosis and cirrhosis in an animal model.
However, the reduced enhancement is not directly related to the
degree of chronic liver damage, which limits the diagnostic value
of superparamagnetic contrast agents in the assessment of chronic
liver disease.
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