Contrast-enhanced Ultrasonography of Different Focal Nodular Lesions during Hepatocarcinogenesis Complicating Cirrhosis

Objective To explore the difference of contrast-enhanced phase and pattern in different focal nodular lesions smaller than 3cm during cirrhotic hepatocarcinogenesis and its value on differential diagnosis by observing imaging characteristics of those nodules using contrast-enhanced ultrasonography(CEUS) and comparing with Doppler ultrasonography(DUS) and contrast-enhanced helical CT appearance.Methods 69 focal noduler lesions found in 58 cirrhotic patients by conventional ultrasonography were studied using SonoVue and Contrast Pulse Sequencing(CPS) technique and their CEUS characteristics were analyzed.All the nodules were underwent ultrasound-guided biopsy or surgery.13 large regenerative nodules(LRN),26 dysplastic nodules(DN) and 30 small hepatocellular carcinomas(SHCC) were confirmed pathologically.Results After CEUS,the beginning-enhanced time and entire wash-out time showed desending trend along LRN,LGDN,HGDN,welldifferentiated SHCC and medium-poor-differentiated SHCC.Six enhancement patterns were summerized in this study,92.3% LRN presented Ⅰ or Ⅱ patterns,58.3% LGDN presented Ⅲ pattern,83.8% HGDN mostly presented Ⅳ pattern,83.3% SHCC presented Ⅴ or Ⅵ patterns,well-differentiated SHCC mostly presented Ⅴ pattern,medium-poor-differentiated SHCC presented distinctive pattern Ⅵ,one case of DN which turn malignant presented mixed pattern Ⅲ and Ⅴ.The ability of CEUS in differentiating malignant from benign or precancerous nodules is superior to that of conventional ultrasound(P0.01).There was no significance(P0.05) in enhanced effect by CEUS and contrast-enhanced CT.Conclusion CEUS improved the power of conventional ultrasonography in judging the nature of focal nodular lesions in cirrhotic livers and from observing the difference of CEUS phase and pattern can we make preliminary estimation on their development,evolvement and pathological types during hepatocarcinogenesis.