Differentiation of hepatic tumors by color Doppler imaging: role of the maximum velocity and the pulsatility index of the intratumoral blood flow signal

Abstract

Doppler spectral analysis using color Doppler ultrasonography (US) was performed in a total of 133 patients with 135 hepatic tumors, including 88 hepatocellular carcinomas (HCCs), 30 metastatic hepatic cancers, 15 hemangiomas and 2 focal nodular hyperplasias (FNHs). Mean +/- SD of maximum velocity (Vmax) in hemangiomas (15.0 +/- 16.0 cm/s) was significantly lower than in HCCs (34.9 +/- 26.7 cm/s) and in metastases (37.9 +/- 17.4 cm/s). Mean +/- SD of the pulsatility index (PI) in hemangiomas (0.45 +/- 0.41) was significantly lower than in HCCs (1.52 +/- 0.71) and metastases (1.44 +/- 0.43). Mean +/- SD of Vmax and PI in FNH was 20.0 +/- 11.3 cm/s and 0.90 +/- 0.35, respectively. HCC showed a wide spectrum in terms of Vmax and PI; however, 18% of the HCC nodules had relatively high PI (>2.0). Specificity of Vmax more than >60 cm/s and PI more than 2.0 for the diagnosis of HCC were 92 and 94%, respectively. On the other hand, 87% of hemangiomas showed relatively lower Vmax (<30 cm/s) and 87% of hemangiomas showed relatively low PI (<1.0 cm/s). Specificity of Vmax less than 30 cm/s and PI less than 1.0 for the diagnosis of hemangioma were 47 and 78%, respectively. When taking account of both parameters, Vmax and PI, diagnostic efficacy for hemangioma and HCC was greatly improved (sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 80, 86, 85, 41 and 97%, respectively, in hemangioma, and 38, 85, 54, 83 and 58%, respectively, in HCC) as compared with the results with Vmax or PI alone. In conclusion, in addition to the information obtained by Vmax, simultaneous measurement of PI adds valuable information useful in the noninvasive differentiation among hepatic tumors by Doppler spectral analysis at color Doppler US.