Hypoechoic focal liver lesions: characterization with contrast enhanced ultrasonography.
OBJECTIVE
To evaluate the late sinusoidal phase of contrast enhancement with a 2nd-generation ultrasound contrast enhanced medium in the characterization of hypoechoic focal liver lesions.


METHODS
We studied 88 hypoechoic liver lesions (diameter range, 1-18 cm; with 18 lesions 2 cm or less) found on conventional grayscale sonography (US) with contrast-enhanced ultrasonography (CEUS). Final diagnosis was made using contrast enhanced helical CT, contrast enhanced MR, angiography (DSA), and/or histopathic confirmation or clinical imaging follow-up.


RESULTS
There were 37/88 benign lesions demonstrated: 17 cavernous hemangiomas, 3 capillary hemangiomas, 11 focal nodular hyperplasias (FNH), 3 focal areas of sparing in hepatic steatosis, 2 adenomas, and 1 intrahepatic necrotic area. Malignant lesions demonstrated included 51/88: 27 hepatocellular carcinomas (HCC) in cirrhosis, 11 metastatic carcinomas, 10 metastatic endocrine tumors, 2 cholangiocellular carcinomas (CCC) and 1 non-Hodgkin's lymphoma (NHL). CEUS characterized 30/37 (81%) benign lesions and 45/51 (88%) malignant lesions. On the basis of the results obtained during the sinusoidal contrast enhanced phase of CEUS, diagnosis of benignancy was possible in 35/37 (95%) of benign liver lesions and diagnosis of malignancy in 49/51 (96%) of malignant liver lesions. The enhancement pattern of 13 small (< or = 2 cm in diameter) hypervascular liver lesions (3 capillary hemangiomas, 2 FNHs, 4 HCCs, 4 metastatic endocrine tumors) was better demonstrated on CEUS than on helical CT. In these cases the hyper vascularization of the lesions shown on CEUS was not confirmed on CT.


CONCLUSIONS
CEUS distinguished malignant from benign hypoechoic liver lesions with an accuracy of 95%.
D'Onofrio
Mirko
M
Department of Radiology, Policlinico G.B. Rossi, University of Verona, Italy.
Rozzanigo
Umberto
U
Masinielli
Bianca Maria
BM
Caffarri
Sabrina
S
Zogno
Andrea
A
Malagò
Roberto
R
Procacci
Carlo
C
D015901:Angiography, Digital Subtraction; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D010743:Phospholipids / Q000008:administration & dosage*; D011446:Prospective Studies; D013459:Sulfur Hexafluoride / Q000008:administration & dosage*; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000379:methods*
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride