To compare the detective capability of focal liver lesion(FLL) between the conventional ultrasound and contrast-enhanced ultrasound(CEUS).

Clinical data of 54 patients with FLL, who received conventional ultrasound and CEUS examination in Department of Ultrasound, the Third Affiliated Hospital of Sun Yat-sen University from August 2006 to January 2011, were analyzed retrospectively. There were 47 males and 7 females with the mean age of(52±15) years old. The informed contents of all patients were obtained and the ethical committee approval was recieved. Conventional ultrasound examination(including B-mode and color Doppler ultrasound) was performed firstly, then CEUS examination was used with contrast pulse sequence imaging technique and contrast agent(SonoVue). The confirmation was made according to the results of enhanced computed tomography(CT) or magnetic resonance imaging(MRI), puncture or surgical pathological diagnosis, and follow-up results. The results of two methods were compared by Chi-square test.

Of 54 cases, 33%(18/54) FLL could not be detected or clearly displayed by conventional ultrasound, while could be clearly displayed and diagnosed by CEUS. A total of 178 lesions were finally confirmed in 54 patients, including 123 hepatocellular cancer (HCC) lesions, 7 intrahepatic cholangiocarcinoma(ICC) lesions, 30 metastatic hepatic carcinoma lesions, 18 hepatic hemangioma lesions. In the above 4 kinds of lesions, 46, 2, 7, 7 lesions were detected by conventional ultrasound respectively and 114, 5, 23, 16 by CEUS respectively. There were significant differences between two methods in the diagnosis of HCC, metastatic hepatic carcinoma and hepatic hemangioma (χ²=112.083, 17.076, 9.753; P<0.05) . The detective rate of conventional ultrasound and CEUS was 34.8%(62/178) and 88.8%(158/178) respectively. There was significant difference between two methods (χ²=109.656, P<0.05) . Five out of 75 lesions with the diameter smaller than 10 mm, 5 lesions were detected by conventional ultrasound, while 66 lesions were detected by CEUS. There was significant difference betwwen two methods (χ²=99.510, P<0.05) . In 85 lesions with the diameter from 10 to 30 mm, 39 lesions were detected by conventional ultrasound, while 74 lesions were detected by CEUS. There was significant difference betwwen two methods (χ²=32.332, P<0.05) . Eighteen lesions with diameter larger than 30 mm could be detected by conventional ultrasound and CEUS.

The detective capability of CEUS for FLL is superior to the conventional ultrasound. CEUS can especially improve the detective rate of small lesions with subcentimeter in the liver and has better clinical application value.