Application of contrast-enhanced ultrasound to increase the diagnostic rate of liver tumor by biopsy

Objective To evaluate the clinical utility of contrast-enhanced ultrasound (CE US) in percutaneous liver biopsy of focal liver lesions. Methods Two hundred and eleven patients with unidentified space occupying les ions in liver, 112 males and 74 females, aged 52 (16-78), were randomly divided into 2 groups: CEUS group in which 96 cases with 149 lesions underwent liver bi opsy with 21-18 gauge needles directed by real time grey CEUS, and routine ultr asound (US) group in which 115 patients with 153 lesions underwent biopsy guided by conventional ultrasonography. There was no significant difference in the siz e of lesions between these 2 groups. There were 75 minute malignant lesions with the size of ≤2.0 cm (24.8%) in 67 patients, 12.9% in the CEUS group and 11.9% in the US group. Obtainment of adequate specimen for pathological examination me ant successful biopsy. Definite diagnosis was made by the combination of the res ults of pathological examination, CEUS, CT, MRI, angiography, serum alpha-fetop rotein, and 3 to 6- month follow-up. Results The proportion of no more than 2 puncture attempts in the CEUS group was 33/19, significantly higher than that in the US group (8/153, P=0.0007). The biopsy success rate of the CEUS group was 98.7%, significantly higher than that of the US group (91.5%, P =0.0096). The accurate diagnosis rate of the CEUS group was 96.0%, significantly higher than that of the US group (87.6%, P=0.0165). The accurate diagnosis rate of malignant lesions with the size of ≤2.0 cm in the CEUS group was 97.4%, significantly higher than that in the U S group (80.6%, P=0.0473). Among the 112 confirmed malignant lesions in the US group 15 had been diagnosed as benign by pathological examination of the biop sy specimens with a false negative rate of 13.4%. The relevant patients underwen t CEUS-guided biopsy again and 14 of the 15 lesions were confirmed as malignant finally and the size of 6 of the 14 lesions was ≤2.0 cm. Except for one case o f pneumothorax in the US group no major complication occurred. Conclusion Biopsy guided by CEUS is more accurate in location and diagnosis of m alignant lesions and minute tumors in the liver, thus increasing the success rat e of biopsy and the confirmed diagnosis rate of malignant lesions.