Hepatocellular carcinoma (HCC) is a common primary malignant tumor of the liver with high morbidity and poor prognosis (Digumarthy et al., 2005). Distinguishing HCC from pre-cancer is critical for therapeutic and prevention strategies. Magnetic resonance imaging and spectroscopy (MRI/S) can potentially be used for diagnosis and monitoring but existing methods are unable to detect early changes. Using a pre-clinical model of liver cancer in the rat, induced by choline and methionine deficient diet, we have investigated by MRI and MRS key bio-indicators including lipid signal change, transverse relaxation time (T2), distribution of lipid accumulation by phase interference imaging, and variation of apparent diffusion coefficient (ADC) with exposure to diet in a group of 9 rats (currently up to 24 weeks on diet). In our latest measurements, we have found that the mean T2 value of abnormal liver is significantly larger (34 ms ± 3.91, p < 0.005) than those in the normal tissue (23 ms ± 1.71). These correspond with dark regions in opposed phase images indicating the cancellation of MR signal by a significantly large lipid pool contribution. Preliminary work measuring ADC’s also shows a significant difference in these regions. In addition, localized spectroscopy showed elevated lipid signal in the MR spectrum. It is known that lipid accumulation precedes tumour development (Griffitts et al., 2010) but was previously difficult to capture in a systematic method. Here we propose that the combination of T2, ADC, phase interference and localized spectroscopy will be a powerful new indicator of early detection in liver cancer.
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