| Objective: To investigate the clinical application value of diffusion -weighted MR imaging in the hepatic neoplasms at 3 Tesla magnetic resonance.Methods: 3.0T magnetic resonance diffusion-weighted imaging(DWI) was obtained in a total of 30 normal cases and 133 patients with liver focal masses(liver cyst 40, liver hemangioma 35, hepatocellular carcinoma 35, liver metastasis 23 ). The characteristics of the DWI and measurement of apparent diffusion coefficient (ADC) values were analyzed. The ratio of the ADC values of hepatocellular carcinoma and liver metastasis lessons/liver were calculated.Rusults: Most of hepatocellular carcinoma (HCC) and liver metastasis showed complex signals on DWI . The parenchyma part of HCC showed high signals, but the necrotic part showed low signals . The edge of tumors was clearly showed, The signals of the lesions were lessened when b value was increased . The hepatic cyst showed the homogenous high signals on DWI. and the signals were obviously decreased or vanished when b value was increased. Hemangiomas showed homogenous high signal on DWI, and the signals intensity was between HCC, liver metastasis and hepatic cysts. The signals intensity on ADC was totally opposite to that on DWI.When the b value was 400 s/mm2, the mean ADC value of normal liver is (1.19±0.23)×10-3mm2/s, Distinctive ADC values were found in liver lesions. The ADC value (l×10-3mm2/s) of liver cysts, liver hemangiomas, hepatocellular carcinoma and liver metastasis were2.89±0.30, 2.45±0.24, 1.89±0.38, 1.95±0.20. There were significant differences between malignant and benign lesions. The difference between the mean ADC value wassignificant (t=14.730, P<0.01) . the ADC threshold between malignant andbenign lesions was 2.15×10-3mm2/s, the sensitivity, specificity, accuracy were96.55%, 98.67%, 97.74% respectively. The ADC value in the same lesion showed significant differences at different b values. The decrease degree of the ADC value was different in different lesions. The higher the b value became, the worse the quality of the DWI of the little lesions. The hepatocellular carcinoma and liver metastasis showed no statistical significance (t=0.698, P=1.3760) . The ratio of the ADC values of lessons/liver in hepatocellular carcinoma and liver metastasis was 0.89±0.20 and 1.41±0.35 respectively ,there were significant different between both (t=7.199, P<0.05) .Conclusion: According to DWI, ADC value and their changing characteristics, Diffusion-weighted 3. OT MR imaging is useful in differentiated diagnosis of liver focal masses and advantage to show of the lessons. It can be one of the routine sequence in the liver examination.
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