Contrast Enhanced Ultrasound for the Evaluation of Focal Liver Lesions - a Multi-center Study on the Usefulness in the Clinical Practice

Focal liver lesions (FLL) are quite frequently discovered in daily practice at routine ultrasound and sometimes require the use of extensive investigations for a correct diagnosis, thus increasing the costs and duration of diagnosis. On the other hand, due to screening strategies for patients with liver cirrhosis, FLL are discovered very early in these patients, and they must be evaluated in order to establish a therapeutic strategy (including transplantation, surgical resection or percutaneous echoguided procedures).

Contrast enhanced ultrasound (CEUS) using second generation contrast agents is a relatively new imaging modality that allows the characterization of FLL and allows a positive diagnosis based on the vascular pattern of the lesion. The advantages of this method are the low cost as compared with other imaging modalities and the fact that it can be performed immediately after standard abdominal ultrasound, so approximately 5 minutes after CEUS (the total duration of this investigation) a confident diagnosis can be obtained.

The place of CEUS in the diagnostic algorithm of FLL is not very well established. The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) issued the first Guidelines regarding the use of CEUS in 2004, revised in 2008, in which the main indications of this method are presented.

The purpose of this study is to establish the value of CEUS in the evaluation of de novo FLL in clinical practice.

The study will include patients discovered with de novo FLL at standard ultrasound in which the ultrasound study is not conclusive for the positive diagnosis (the patients with simple cysts or known FLL under CEUS follow up will be excluded form the study). The standard ultrasound will be followed by the contrast study using SonoVue® (Bracco, Italy) as contrast agent. The amount of contrast agent will be documented in every patient (it depends on the ultrasound machine used and the suspected diagnosis). The examination will be performed using the dedicated contrast software of each ultrasound machine used in the study. The investigators shall also document in every patient: the indication for CEUS study, a short history including the presence of chronic hepatopathies or malignancies, the ultrasound machine used and the operator. Each examination will last about 5 min after bolus injection and will be documented by 4 video files no longer than 30 seconds each, containing: The standard study, the arterial phase, the portal phase and the late phase. Additional loops can be stored whenever it is considered necessary.