Ultraschall Med 2005; 26 - OP155
DOI: 10.1055/s-2005-917436

ANGIOSONOGRAPHIC PATTERN OF FOCAL NODULAR HYPERPLASIA: EVALUATION IN 65 LESIONS

P Tittoto 1, E Accogli 2, A Domanico 2, L Riccardi 1, M Pompili 1, G Gasbarrini 1, V Arienti 2, GL Rapaccini 1
  • 1Istituto di Medicina Interna e Geriatria. Policlinico “A.Gemelli“, Università Cattolica del Sacro Cuore, Roma
  • 2Centro di Ricerca e Formazione in Ecografia Internistica, Interventistica e Vascolare- Medicina Interna Arienti, Ospedale Maggiore, Bologna

Purpose: Focal nodular hyperplasia (FNH) is the second most common benign liver tumor after hemangioma and shows an autoptic prevalence of 0.9%. FNH is often an incidental finding at ultrasound (US) imaging. The differential diagnosis between FNH and other hypervascular liver lesions such as hepatocellular adenoma, hepatocellular carcinoma and hypervascular metastases is critical to ensure proper treatment, and often requires multiphasic computed tomography (CT) and magnetic resonance imaging (MRI). Recently, the use of contrast-enhanced harmonic ultrasound (CEHUS) with 2nd generation contrast agent has led to improved characterization of FNH. However, to our knowledge, the angiosonographic pattern of FNH at CEHUS has not yet been investigated in a large series of patients. Then, the aim of our study was to describe the perfusion pattern of FNH at CEHUS.

Methods and Materials: Sixty-five lesions (mean Ø: 36.4mm; range: 5–90mm) detected in 48 patients (43F/5M, mean age: 40.6 ys; range: 17–77 ys) were evaluated by baseline gray-scale US and Color-Power Doppler US by four experienced sonographers working in 2 hospitals. The lesions were subsequently scanned by CEHUS after IV bolus administration of 2.4ml of Sonovue (SF6, Bracco, Milan, Italy) by employing continuous imaging at low mechanical index (CnTI, Esatune and MPX, Esaote, Genova, Italy). The final diagnosis of FNH was provided by CT and/or MRI, and, in doubtful cases, by US-guided biopsy or surgical resection.

Results: The baseline US study with Color and Power Doppler evaluation were suggestive of FNH in 19/65 cases (29%). At CEHUS all lesions showed a constant enhancement pattern (early arterial homogeneous enhancement pattern persistent in the portal phase) that was comparable to that found on multiphasic CT and/or MRI. Furthermore, in 26/65 cases (40%), the typical anatomic features of FNH such as “central scar“ and/or early “spoke wheel arteries“ were clearly visible.

Conclusions: According to our data, obtained from a very large series of lesions, FNH shows on CEHUS a typical enhancement pattern in all cases. This technique appears promising in the rapid characterization of this benign lesion.