Small nodules (1-2 cm) in liver cirrhosis: characterization with contrast-enhanced ultrasound.
OBJECTIVE
To determine the diagnostic efficacy of arterial phase contrast-enhanced ultrasound (CEUS) for characterizing small hepatic nodules (1-2 cm) in patients with high-risk for hepatocellular carcinoma (HCC).


METHODS
Over 12 months, CEUS was performed in 59 patients at high-risk for HCC with small hepatic nodules (1-2 cm; mean, 1.5 cm). Based only on arterial phase (<45 s) vascular intensity and pattern, lesions were prospectively diagnosed as HCC if there was hypervascularity without known features of hemangioma. The diagnosis of HCC was made regardless of the presence or absence of washout. Verification of diagnosis was made by liver transplantation (n=13), biopsy (n=12), resection (n=3) or clinical and imaging follow-up for at least 12 months (n=31).


RESULTS
At of the time of CEUS, the 59 nodules were diagnosed as HCC in 26 and benign lesions in 33, including 20 regenerative/dysplastic nodules (RN/DN), 11 hemangiomas, and 2 focal fat sparing. All 26 nodules with arterial phase hypervascularity without hemangioma-like features were HCC. However, CEUS misdiagnosed HCC as RN/DN in 4 cases with arterial iso- (n=3) or hypovascularity (n=1). CEUS correctly diagnosed all 11 hemangiomas. The sensitivity, specificity, and accuracy of CEUS for diagnosing HCC were 86.7, 100, and 93.2%.


CONCLUSIONS
Arterial phase vascular intensity and pattern of CEUS are highly accurate for the diagnosis of small (1-2 cm) HCC and hemangioma in liver cirrhosis. On CEUS, arterial phase hypervascularity without a hemangioma-pattern alone may be sufficient for diagnosis of small HCC. Infrequent iso/hypovascular HCC may erroneously suggest RN/DN necessitating biopsy or close follow-up.
Jang
Hyun-Jung
HJ
Department of Medical Imaging, Toronto General Hospital, University of Toronto, Toronto, Ontario M5G 2N2, Canada.
Kim
Tae Kyoung
TK
Wilson
Stephanie R
SR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D005466:Fluorocarbons; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000209:etiology; D008113:Liver Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography
D003287:Contrast Media; D005466:Fluorocarbons; C042852:perflutren