Anita Andreano MD, Presenter: Nothing to Disclose

Paul F. Laeseke PhD, Abstract Co-Author: Stockholder, NeuWave Medical Inc, Madison, WI Consultant, NeuWave Medical Inc, Madison, WI

Matteo Passamonti MD, Abstract Co-Author: Nothing to Disclose

Sandro Sironi MD, Abstract Co-Author: Nothing to Disclose

Laura Romanini MD, Abstract Co-Author: Nothing to Disclose

Franca Meloni MD, Abstract Co-Author: Nothing to Disclose

Contrast-enhanced ultrasonography (CEUS) can more accurately characterize focal liver lesions when compared with conventional B-mode ultrasound (US). The purpose of this study was to determine the ability of CEUS to characterize incidental liver lesions as either benign or malignant using computed tomography (CT) or magnetic resonance (MR) imaging as the reference standard.

One hundred forty five patients (64 males and 81 females; mean age, 52 years) with no known history of neoplastic disease had 162 solid focal liver lesions discovered incidentally on conventional US between January 2002 and December 2005. All lesions were considered indeterminate and were subsequently evaluated with CEUS. CEUS was performed using SonoVue (Bracco, Milan, Italy). Lesions were classified according to a four-point scale as benign, probably benign, probably malignant or malignant. Area under the ROC curve, sensitivity and specificity at each cut-off level were calculated using contrast-enhanced CT (86 lesions), MR imaging (45) or both (31) as the reference standard. Fine needle aspiration was required to reach the diagnosis in eight lesions.

One hundred thirty lesions were considered benign, 20 probably benign, 2 probably malignant and 10 malignant using CEUS. Area under ROC curve was 0.98. Sensitivity and specificity in characterizing lesion as non benignant (probably malignant or malignant) were respectively 83,3% and 98,7%. The following diagnoses were made using the reference standard: hemangioma (n=80), cyst (n=9), focal nodular hyperplasia (n=28), adenoma (n=7), skip area in fatty liver (n=22), hydatid cyst (n=2), brucellar cyst (n=1), regenerative nodule in cirrhosis (n=1), hepatocellular carcinoma (n=6), metastasis (n=6). Using CEUS, the correct diagnosis was made in 150/162 (92.6%) lesions, the incorrect diagnosis was reached in 5/162 (3.1%) lesions and the lesion could not be diagnosed in 7/162 (4.3%) lesions.

CEUS can be used to characterize incidental liver lesions as either benign or malignant, reducing the need for further diagnostic imaging. Moreover, CEUS can be used to diagnose a focal liver lesion right after it is discovered on conventional sonography and, unlike CT, CEUS is not associated with concerns of exposure to radiation.

CEUS can be used to characterize focal liver lesion found incidentally in otherwise healthy patients as either benign or malignant.

Andreano, A, Laeseke, P, Passamonti, M, Sironi, S, Romanini, L, Meloni, F, Contrast-enhanced Ultrasound: A Useful Diagnostic Tool to Distinguish Benign from Malignant Incidental Liver Lesions.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6018465.html