1Department of Radiology, Ewha Womans University, Korea. 2Department of Internal Medicine, Ewha Womans University, Korea.
Published online: September 1, 2001.
ABSTRACT
PURPOSE: The purpose of this study was to differentiate dysplastic nodule (DN) from hepatocellular carcinoma (HCC) in patients with liver cirrhosis on contrast-enhanced power and pulsed Doppler US. MATERIALS AND METHODS: Twenty-one patients with liver cirrhosis and a focal lesion were included. They consisted of biopsyproven 12 DNs(mean diameter: 1.8 cm, M:F = 5:7, mean age 60) and 9 HCCs(mean diameter: 2.3cm, M:F = 6:3, mean age 63). All the patients were prospectively examined with Acuson Computed Sonography 128XP/10 and 4MHz vector transducer. Gray-scale US was done to assess the echogenicity of the focal lesion. Vascular flow signals within the focal lesion were examined with power Doppler US. After the injection of 7ml(300mg/ml) suspension of US contrast agent (Levovist, Schering, Berlin, Germary), vascular flow signals were graded to 4 grades on power Doppler US. Arterial and/or venous flow pattern on pulsed Doppler US were evaluated. Statistical analysis was done using chi-square method. RESULTS: On gray-scale US, 10 (83%) DNs showed hypoechogenicity and the other two (17%) showed hypere-chogenicity. 7 (78%) HCCs were hypoechoic and two (22%) were hyperechoic. On non-enhanced power Doppler US, all 12 cases (100%) of DNs had no vascular flow signal and four cases of nine HCCs (grade II : three, grade III : one) revealed vascular flow signals (p=0.429). On contrast-enhanced power Doppler US, 11 cases (92%) of DNs and all cases (100%) of HCCs showed increased vascular flow signals. Three (24%) of DNs and 7(78%) of HCCs showed grade III and IV . There was a statistical difference in the grade of vascular flow signals between two groups (p=0.03). On pulsed Doppler US, the arterial flow was present in 2 (17%) DNs and 8 (89%) HCCs (p=0.002) and venous flow was present in 11 (92%) DNs and 5 (56%) HCCs. Combined flow appeared in 2 cases (16%) of DNs and 4 cases (44%) of HCCs. CONCLUSION: In differentiating DN from HCC, the higher probability of HCC can be considered if a focal lesion in cirrhotic patient has grade III or IV of vascular flow signals on contrast-enhanced power Doppler US and arterial flow on pulsed Doppler US.