Orlando Catalano, Presenter: Nothing to Disclose

Antonio Nunziata MD, Abstract Co-Author: Nothing to Disclose

Fabio Sandomenico MD, Abstract Co-Author: Nothing to Disclose

Sergio Venanzio Setola MD, Abstract Co-Author: Nothing to Disclose

Alfredo Siani MD, Abstract Co-Author: Nothing to Disclose

Complex cystic FFLs may be malignant as well as cystic-like FFLs at US may turn out solid. We report on the additional value of contrast injection in the differentiation of cystic and apparently-cystic FFLs.

In a 2-year period we submitted to second-generation contrast medium enhanced, low-mechanical index US all patients with cystic lesions indeterminate at baseline US. The features indicating an indeterminate cyst included slightly inhomogeneous or hypoechoic content, absence of posterior enhancement, ill-defined and/or thick borders, irregular internal septa, mural nodules. Cyst with mural calcifications and clustered cysts with thin and incomplete septa were regarded as benign and excluded. CEUS findings for malignancy included any degree of internal content enhancement and mural/septal/nodular arterial-based enhancement. US-based and CEUS-based diagnoses were categorized as definitive, probable but requiring further investigation, uncertain.

We enrolled 24 consecutive patients with 49 FLLs (1-6/pt., mean 2). Lesion size was 11-79 mm (mean, 22 mm). Sixteen subjects had a known extrahepatic malignancy. Final diagnosis included 27 mets, 4 hematomas/hemorrhagic cysts, 3 hemangiomas, 3 biliary cystadenomas, 2 biliary cystadenocarcinomas, 2 abscesses, 2 parasitic cysts, 1 hepatocellular carcinoma, 1 biloma, and 4 benign “dirty” cysts. No FLL was diagnosed as certain at unenhanced US imaging (inclusion criterion) while 8 were regarded as probable but requiring further investigation and 41 as uncertain. CEUS correctly identified all malignancy cases but was unable to differentiate a biliary cystadenoma from its malignant type. Forty FLLs were diagnosed as certain at CEUS imaging, 9 as requiring further assessment, and none as uncertain. Malignant FLLs showed arterial-phase hyper-enhancement with portal- and especially late-phase wash out. Benign FLLs showed persistent enhancement through all phases (cystadenomas) or no enhancement throughout all phases (other benign lesions).

Contrast medium injection can be useful in differentiating both cystic-looking solid liver lesions from true cysts and benign cysts from malignant ones in cases indeterminate at US.

Cystic FFLs may be malignant while cystic-like FFLs may be solid. CEUS allows an accurate differentiation of complex cysts indeterminate at baseline US, avoiding referral to other imaging modalities.

Catalano, O, Nunziata, A, Sandomenico, F, Setola, S, Siani, A, Contrast-enhanced Ultrasound (CEUS) in the Assessment of Cystic and Cystic-like Focal Liver Lesions (FLLs).  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007512.html