Contrast-Enhanced Ultrasound Findings in Patients with Rare Solitary Necrotic Nodule of the Liver - a Multicenter Report.

PURPOSE: This multicenter retrospective study highlights the contrast-enhanced ultrasound (CEUS) findings in a series of histologically proven solitary necrotic nodules (SNN) of the liver, a poorly understood pathologic entity of uncertain origin that mimics malignancy. MATERIALS AND METHODS: 22 patients (M/F 13/9; mean age 59.4 years, SD ±â€Š10.7, range 35-81) with histological diagnosis of SNN and CEUS were selected from clinical, imaging, and pathological archives of 7 US interventional centers, each of which provided 1 to 6 cases (mean 2.8). Pathological diagnosis was made on 20 US-guided biopsies and 2 surgical specimens. 2 patients had 2 SNNs with identical CEUS findings so that imaging analysis was carried out on 24 nodules. RESULTS: SNN was an incidental finding in healthy people in 10 cases (45.5 %), and it was discovered during follow-up for either known extrahepatic malignancies (9 cases = 41 %) or chronic liver disease (3 cases = 13.5 %). SNNs had a mean size of 19.3 mm (SD ±â€Š6.5, range 9-40). On B-mode US, SNNs appeared hypoechoic in 14 cases (66.7 %), "target-like" in 7 cases (29.2 %), and homogeneously hyperechoic in 1 case (4.1 %). On CEUS, all lesions appeared devoid of contrast enhancement ("punched out" aspect) in the arterial, portal venous, and late phases after US contrast agent injection. A uniformly thin, hyperenhancing ring in the early arterial phase and isoenhanced with the surrounding parenchyma in the portal venous and late phases was found in 10 nodules (41.6 %). Clinical and imaging follow-up (mean duration 42.2 months, SD ±â€Š34.9, range 2-108) was available in 15 patients with 16 SNNs: no changes in size and echostructure were seen. CONCLUSION: CEUS can contribute to the diagnosis of SNN when a "punched out" appearance in all vascular phases with or without thin rim enhancement in the very early arterial phase is present in healthy subjects in whom a focal liver lesion is incidentally found. In patients with a history of chronic liver disease or malignancy, US-guided biopsy represents the unavoidable first-line diagnostic modality.

Role of Contrast-Enhanced Ultrasound in the Detection of Complications After Ultrasound-Guided Liver Interventional Procedures.

The role of contrast-enhanced ultrasound (CEUS) in interventional ultrasound-guided procedures in the liver has been increasingly recognized. However, little is known about the capability of CEUS for diagnosing complications after liver biopsy and ablation with special regard to postprocedural hemorrhage. The aim of this Pictorial Essay is to present the CEUS features of a wide spectrum of vascular complications (with or without bleeding) and injuries of the surrounding abdominal and chest wall occurring after liver interventional procedures.

External validation of the ITA.LI.CA prognostic system for patients with hepatocellular carcinoma: A multicenter cohort study.

Several staging systems for hepatocellular carcinoma (HCC) have been developed. The Barcelona Clinic Liver Cancer staging system is considered the best in predicting survival, although limitations have emerged. Recently, the Italian Liver Cancer (ITA.LI.CA) prognostic system, integrating ITA.LI.CA tumor staging (stages 0, A, B1-3, C) with the Child-Turcotte-Pugh score, Eastern Cooperative Oncology Group performance status, and alpha-fetoprotein with a strong ability to predict survival, was proposed. The aim of our study was to provide an external validation of the ITA.LI.CA system in an independent real-life occidental cohort of HCCs. From September 2008 to April 2016, 1,508 patients with cirrhosis and incident HCC were consecutively enrolled in 27 Italian institutions. Clinical, tumor, and treatment-related variables were collected, and patients were stratified according to scores of the Barcelona Clinic Liver Cancer system, ITA.LI.CA prognostic system, Hong Kong Liver Cancer system, Cancer of the Liver Italian Program, Japanese Integrated System, and model to estimate survival in ambulatory patients with hepatocellular carcinoma. Harrell's C-index, Akaike information criterion, and likelihood-ratio test were used to compare the predictive ability of the different systems. A subgroup analysis for treatment category (curative versus palliative) was performed. Median follow-up was 44 months (interquartile range, 23-63 months), and median overall survival was 34 months (interquartile range, 13-82 months). Median age was 71 years, and patients were mainly male individuals and hepatitis C virus carriers. According to ITA.LI.CA tumor staging, 246 patients were in stage 0, 472 were in stage A, 657 were in stages B1/3, and 133 were in stage C. The ITA.LI.CA prognostic system showed the best discriminatory ability (C-index = 0.77) and monotonicity of gradients compared to other systems, and its superiority was also confirmed after stratification for treatment strategy. CONCLUSION: This is the first study that independently validated the ITA.LI.CA prognostic system in a large cohort of Western patients with incident HCCs. The ITA.LI.CA system performed better than other multidimensional prognostic systems, even after stratification by curative or palliative treatment. This new system appears to be particularly useful for predicting individual HCC prognosis in clinical practice. (Hepatology 2018;67:2215-2225).

Biopsy of Liver Target Lesions under Contrast-Enhanced Ultrasound Guidance - A Multi-Center Study.

PURPOSE: To retrospectively characterize the prevalence and impact of contrast-enhanced ultrasound (CEUS) as a guidance technique for the biopsy of liver target lesions (LTLs) at six interventional ultrasound centers. MATERIALS AND METHODS: The six participating centers retrospectively selected all patients in whom biopsy needles were positioned in LTLs during CEUS. The prevalence of CEUS-guided biopsies at each center between 2005 and 2016, contrast agent consumption, procedure indications, diagnostic yield and complications were assessed. Informed consent was obtained for all patients. RESULTS: CEUS-guided biopsy of LTLs was carried out in 103 patients (68 M/35 F, median age: 69 yrs) with 103 liver target lesions (median size: 20 mm) using cutting needles (18 - 20 g) in 94 cases (91.2 %). CEUS-guided biopsy represented 2.6 % (range: 0.8 - 7.7 %) of 3818 biopsies on LTLs carried out at the participating centers. Indications to CEUS-guided biopsy were: a target lesion not visible on non-enhanced US (27.2 %), improvement of conspicuity of the target (33 %), choice of non-necrotic area inside the target (39.8 %). 26 patients (25.2 %) had a previously non-diagnostic cyto-histological exam. The diagnostic accuracy of the technique was 99 %. No major complications followed infusion of contrast agent or biopsy performance. CONCLUSION: The indications for CEUS-guided biopsy for LTLs are limited, but CEUS can be useful in challenging clinical scenarios, e. g. poorly visualized or invisible lesions or sampling of non-necrotic areas in the target lesions. There is also a potential advantage in using CEUS to guide repeat biopsies after unsuccessful sampling performed using the standard ultrasound technique.

Management and prognosis of hepatocellular carcinoma in the elderly: Results of an in-field multicenter cohort study.

AIMS: This multicentre cohort study evaluated the role of ageing on clinical characteristics, treatment allocation and outcome of new hepatocellular carcinomas (HCCs), in clinical practice. MATERIAL & METHODS: From September 2008, 541 patients >70 years old (elderly group), and 527 ≤70 years old (non-elderly group) with newly diagnosed HCC were consecutively enrolled in 30 Italian centres. Differences in clinical characteristics and treatment allocation between groups were described by a multivariable logistic regression model measuring the inverse probability weight to meet the elderly group. Survival differences were measured by unadjusted and adjusted (by inverse probability weight) survival analysis. RESULTS: Elderly patients were mainly females, hepatitis C virus infected and with better conserved liver function (P<.001). At presentation, HCC median size was similar in both groups while, in youngers, HCC was more frequently multinodular (P=.001), and associated with neoplastic thrombosis (P=.009). Adjusted survival analysis showed that age did not predict short-mid-term survival (within 24 months), while it was a significant independent predictor of long-term survival. Moreover, age had a significant long-term survival impact mainly on early HCC stages (Barcelona Clinic for Liver Cancer [BCLC] 0-A), its impact on BCLC B stage was lower, while it was negligible for advanced-terminal stages. CONCLUSIONS: Age per se does not impact on short-mid-term prognosis (≤24 months) of HCC patients, and should not represent a limitation to its management.

Long-term effectiveness of resection and radiofrequency ablation for single hepatocellular carcinoma ≤3 cm. Results of a multicenter Italian survey.

BACKGROUND & AIMS: The aim of this study was to compare liver resection and radiofrequency ablation in patients with single hepatocellular carcinoma ≤3 cm and compensated cirrhosis. METHODS: The study involved 544 Child-Pugh A cirrhotic patients (246 in the resection group and 298 in the radiofrequency group) observed in 15 Italian centers. Overall survival and tumor recurrence rates were analyzed using the Kaplan Meier method before and after propensity score matching. Cox regression models were used to identify factors associated with overall survival and tumor recurrence. RESULTS: Two cases of perioperative mortality were observed in the resection group and the rate of major complications was 4.5% in the resection group and 2.0% in the radiofrequency group (p=0.101). Four-year overall survival rates were 74.4% in the resection group and 66.2% in the radiofrequency group (p=0.353). Four-year cumulative HCC recurrence rates were 56% in the resection group and 57.1% in the radiofrequency group (p=0.765). Local tumor progression was detected in 20.5% of ablated patients and in one resected patient (p<0.001). After propensity score matching, both survival and tumor recurrence were still not significantly different although a trend towards lower recurrence was observed in resected patients. Older age and higher alpha-fetoprotein levels were independent predictors of poor overall survival while older age and higher alanine-aminotransferase levels resulted to be independent factors associated with higher recurrence rate. CONCLUSIONS: In spite of a higher rate of local tumor progression, radiofrequency ablation can provide results comparable to liver resection in the treatment of single hepatocellular carcinoma ≤3 cm occurring in compensated cirrhosis.

Adherence to American Association for the Study of Liver Diseases guidelines for the management of hepatocellular carcinoma: results of an Italian field practice multicenter study.

AIM: Adherence to and the applicability of practice guidelines for the management of hepatocellular carcinoma (HCC) in field practice have not been fully addressed. We designed a multicenter field practice prospective study to evaluate the adherence to the 2005 American Association for the Study of Liver Diseases guidelines in Italy. MATERIALS & METHODS: The study began in September 2008 and consecutively enrolled cirrhotic patients with newly diagnosed HCC from 30 local, nonreference centers in Italy. Patients were stratified according to Child-Pugh, the model for end-stage liver disease, tumor-node metastasis, performance status and the Barcelona Clinic Liver Cancer (BCLC) classifications. The diagnostic and therapeutic strategies adopted in each individual patient were recorded. Statistical analysis was carried out on 536 patients using all of the valuable data. RESULTS: A total of 286 (54.5%) patients were ≥70 years old. Comorbidities, recorded in 397 (74%) patients, were classified as moderate to severe in 170 patients (43%). Overall, 174 (59%) patients with early-stage BCLC were ≥70 years; 104 (35%) of these had moderate-to-severe comorbidities and 54% were under a regular US surveillance program. Diagnosis was performed by computed tomography in 93% of patients, contrast-enhanced ultrasound in 62% and MRI in 17%. In patients with nodules of ≤2 cm, adherence to noninvasive diagnostic criteria was 56%. Adherence to the BCLC classification was shown to be suboptimal overall, particularly regarding allocation to surgical procedures, and a total of 119 patients (40%) with BCLC stage A did not receive curative therapies. CONCLUSIONS: This multicenter survey showed that, in the 'real world', adherence to the both the diagnostic and therapeutic American Association for the Study of Liver Diseases 2005 algorithms was low, particularly in patients with early-stage HCC. Difficulties in applying the algorithms in routine clinical practice and the high prevalence of older patients with relevant comorbidities may account for our findings. Strategies to help improve adherence to international guidelines for HCC in field practice are required.

SIUMB recommendations on the use of ultrasound in neoplastic lesions of the gallbladder and extrahepatic biliary tract.

Extrahepatic biliary tract and gallbladder neoplastic lesions are relatively rare and hence are often underrepresented in the general clinical recommendations for the routine use of ultrasound (US). Dictated by the necessity of updated summarized review of current literature to guide clinicians, this paper represents an updated position of the Italian Society of Ultrasound in Medicine and Biology (SIUMB) on the use of US and contrast-enhanced ultrasound (CEUS) in extrahepatic biliary tract and gallbladder neoplastic lesions such as extrahepatic cholangiocarcinoma, gallbladder adenocarcinoma, gallbladder adenomyomatosis, dense bile with polypoid-like appearance and gallbladder polyps.

Assessment of ultrasound acoustic artifacts in patients with acute dyspnea: a multicenter study.

BACKGROUND: Recent reports indicate that numerical assessment of B-lines during transthoracic ultrasound may aid the differential diagnosis of acute diffuse pleuropulmonary disorders. PURPOSE: To determine whether B-lines are different in normal and diseased lungs and whether they can be used to discriminate between different types of pulmonary disorders in acutely ill patients. MATERIAL AND METHODS: In this multicenter study, transthoracic ultrasonography was performed on 193 patients with acute dyspnea, 193 healthy non-smokers, and 58 patients who had undergone pneumonectomy for lung cancer. Examinations were done with a low-medium frequency (3.5-5.0 MHz) convex probe and a high-frequency (8-12.5 MHz) linear probe. Video recordings were re-examined by a second set of examiners. In each participant, we measured the number of B-lines observed per scan. RESULTS: B-lines counts were higher in dyspnoic patients (means: 3.11 per scan per linear probe scan vs. 1.93 in healthy controls and 1.86 in pneumonectomized patients; P < 0.001 for all); all counts were higher when convex probes were used (5.4 in dyspnoic patients and 2 in healthy controls; P < 0.001 vs. the linear probe). Subgroups of dyspnoic patients defined by cause of dyspnea displayed no significant differences in the number of B-lines. CONCLUSION: Our results demonstrate that there are a significant higher number of B-lines in the lungs of patients with dyspnea compared to healthy subjects and to pneumonectomized patients. Nevertheless, the quantification of B-lines does not make any significant contribution to the differential diagnosis of dyspnea.

Survival after locoregional treatments for hepatocellular carcinoma: a cohort study in real-world patients.

Evidence of relative effectiveness of local treatments for hepatocellular carcinoma (HCC) is scanty. We investigated, in a retrospective cohort study, whether surgical resection, radiofrequency ablation (RFA), percutaneous ethanol injection (PEI), and transarterial embolization with (TACE) or without (TAE) chemotherapy resulted in different survival in clinical practice. All patients first diagnosed with HCC and treated with any locoregional therapy from 1998 to 2002 in twelve Italian hospitals were eligible. Overall survival (OS) was the unique endpoint. Three main comparisons were planned: RFA versus PEI, surgical resection versus RFA/PEI (combined), TACE/TAE versus RFA/PEI (combined). Propensity score method was used to minimize bias related to non random treatment assignment. Overall 425 subjects were analyzed, with 385 (91%) deaths after a median followup of 7.7 years. OS did not significantly differ between RFA and PEI (HR 1.11, 95% CI 0.79-1.57), between surgery and RFA/PEI (HR 0.95, 95% CI 0.64-1.41) and between TACE/TAE and RFA/PEI (HR 0.88, 95% CI 0.66-1.17). 5-year OS probabilities were 0.14 for RFA, 0.18 for PEI, 0.27 for surgery, and 0.15 for TACE/TAE. No locoregional treatment for HCC was found to be more effective than the comparator. Adequately powered randomized clinical trials are still needed to definitely assess relative effectiveness of locoregional HCC treatment.

"Starry liver" - Von Meyenburg complex clinical case presentation and differential diagnosis discussion: A case report.

BACKGROUND: Von Meyenburg complex (VMC) (i.e., biliary hamartoma) is a rare congenital disorder characterized by multiple dilated cystic bile ducts, without clear trends in sex or age predominance. Due to the low number of published cases and the lack of recognized guidelines, the management of such patients remains a clinical challenge. CASE SUMMARY: We present a case of symptomatic VMC that was diagnosed after imaging and histopathological examinations. Considering the patient's condition, a conservative treatment strategy was chosen. Instrumental, laboratory, and clinical follow-up demonstrated the stable condition of the patient receiving conservative treatment. CONCLUSION: VMC is a potentially non-life threatening condition, but its recognition is crucial for the management of patients.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part II - Solid lesions.

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic hepatic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the second part of the guideline, concerning the diagnosis and clinical management of hemangioma, focal nodular hyperplasia, and hepatocellular adenoma.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part I - Cystic lesions.

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the first part of the guideline, concerning the characterization of focal hepatic lesions detected by ultrasound, and the diagnosis and clinical management of simple and parasitic hepatic cysts, and of polycystic liver disease.

Which clinical and sonographic parameters may be useful to discriminate NASH from steatosis?

BACKGROUND: The natural history of nonalcoholic steatohepatitis (NASH) includes the passage through steatosis. GOAL: To retrospectively evaluate the usefulness of sonographic parameters compared to histological diagnosis when differentiating steatosis from NASH. STUDY: This retrospective study reviewed records of patients with steatosis from databases of our Departments, selecting only those who had been diagnosed by sonography and liver biopsy [64 males (63.82%); 30 females (36.18%)]. RESULTS: Attenuation of the echo amplitude (P<0.05; odds ratio (OR): 3.43; confidence interval (CI): 1.02-11.57), focal fat sparing (P<0.05; OR: 3; CI: 1.02-11.88) and splenic diameter (P<0.05; OR: 1.66; CI: 1.04-3.26) were independent predictors of NASH. A significantly higher association of attenuation of the echo amplitude, enlarged splenic diameter, and presence of focal fat sparing was observed in NASH patients (P<0.01). CONCLUSIONS: It is very difficult to build a predictive system to distinguish NASH from steatosis based on sonographic scores. However, it is already possible to differentiate NASH from steatosis by combining 3 simple sonographic parameters: attenuation of the echo amplitude, enlarged splenic diameter, and presence of focal fat sparing.

Asymptomatic portal vein aneurysm: Three case reports.

BACKGROUND: Portal vein aneurysm (PVA) is an uncommon vascular dilatation, showing no clear trend in sex or age predominance. Due to the low number of published cases and the lack of management guidelines, treatment of this condition remains a clinical challenge. CASE SUMMARY: We present three cases of asymptomatic PVA; the first and second involve an extrahepatic manifestation, of 48 mm and 42.3 mm diameter respectively, and the third involves an intrahepatic PVA of 27 mm. All were diagnosed incidentally during routine check-up, upon ultrasonography scan. Since all patients were asymptomatic, a conservative treatment strategy was chosen. Follow-up imaging demonstrated no progression in the aneurysm dimension for any case. CONCLUSION: As PVA remains asymptomatic in many cases, recognition of its imaging features is key to favourable outcomes.

SIUMB recommendations for focal pancreatic lesions.

Contrast-enhanced ultrasonography (CEUS) is increasingly being performed in Italy and Europe, particularly in the field of hepato-gastroenterology. Initially, it was mainly carried out to characterize focal hepatic lesions, but, since then, numerous studies have demonstrated its efficacy in the differential diagnosis of focal pancreatic pathologies (D'Onofrio et al. in Expert Rev Med Devices 7(2):257-273, 2010; Vidili et al. in J Ultrasound 22(1):41-51, 2019). The purpose of this paper is to provide Italian Medical Doctors with recommendations and thereby practical guidelines on the management of these patients. The present paper reports the final conclusions reached by the SIUMB guideline commission. This paper addresses particularly percutaneous ultrasound (US) examination (transabdominal US) and is drawn up specifically for publication.

Inflammatory markers and visceral fat are inversely associated with maximal oxygen consumption in women with polycystic ovary syndrome (PCOS).

BACKGROUND: We investigated whether several different inflammatory markers including C-reactive protein (CRP) and fibrinogen and white blood cells (WBCs) count, are associated with maximal oxygen consumption (VO(2 max)) in women with polycystic ovary syndrome (PCOS). METHODS: In PCOS women (n = 124, 24.1 +/- 4.5 year-old) VO(2 max) was measured during symptom-limited cardiopulmonary exercise test. Abdominal fat distribution was determined by ultrasound. Physical activity level was assessed by a standardized questionnaire. CRP was measured by immunoassays, fibrinogen by the Clauss method, and WBCs count with a Coulter counter. RESULTS: Pearson's analysis showed a significant correlation between VO(2 max) and logCRP (r = -0.437, P < 0.001), fibrinogen (r = -0.479, P < 0.001), and WBCs count (r = -0.438, P < 0.001). Multivariable logistic regression model showed that age (beta = -0.127, P = 0.005), AUC(INS )(beta = -0.335, P < 0.001), HDL-C (beta = 0.390, P < 0.001), physical activity score (beta = 0.238, P = 0.002), visceral fat (beta =-0.184), P = 0.023), FAI (beta = -0.291, P = 0.028); CRP (beta = -0.216, P = 0.011), fibrinogen (beta = -0.113, P = 0.008) and WBCs count (beta = -0.177, P < 0.001) were significantly associated with VO(2 max). CONCLUSIONS: Acute-phase reactants, such as CRP and fibrinogen, and WBCs count were independently and inversely associated with a direct measure of cardiorespiratory fitness (VO(2 max)) in women with PCOS, even after adjustment for physical activity level and other potential confounding factors. These findings add to the growing body of evidence linking inflammation to cardiorespiratory fitness in PCOS women.

SIUMB guidelines and recommendations for the correct use of ultrasound in the management of patients with focal liver disease.

The present document describes the SIUMB (Italian Society of Ultrasound in Medicine and Biology) guidelines for the use of ultrasound in the management of focal liver disease. The aim of the paper is to provide a clinical practice guideline for Italian physicians who are approaching the ultrasound study of a focal liver lesion. In particular, these guidelines provide simple indications, recommendations and general practice advices for the correct use of contrast-enhanced ultrasound (CEUS) in this scenario. They represent the SIUMB position of the ultrasound role in the diagnostic flow charts of the principal focal liver lesions, and are in agreement with other, previously published national and international guidelines.

Contrast-enhanced ultrasound patterns of hepatocellular adenoma: an Italian multicenter experience.

PURPOSE: Hepatocellular adenoma (HCA) is a rare benign monoclonal neoplasm, recently categorized on genetic and histopathological basis into four subtypes with different biological behaviors. Since contrast-enhanced ultrasonography (CEUS) is nowadays a well-established technique for liver nodule characterization, the aim of our study was to assess CEUS features of HCAs to identify criteria that correlate with different HCA subtypes as compared to histopathologic examination and other imaging modalities. METHODS: We retrospectively analyzed data of patients with histology-proven HCA who underwent CEUS, computed tomography or magnetic resonance imaging (MRI) in seven different Italian ultrasound units. RESULTS: The study enrolled 19 patients (16 females; 69% with concomitant/prior use of oral contraceptives): the mean size of all HCAs was 4.2 cm (range 1.6-7.1 cm); 14/19 had inflammatory HCAs (I-HCA), 1/19 ß-catenin-activated HCA, and the others unclassified HCAs. On CEUS, during the arterial phase, all but one HCA displayed a rapid enhancement, with 89% of these showing centripetal and 11% centrifugal filling pattern, whereas during the portal and late venous phase 58% of HCA showed washout and the remaining 42% displayed persistent enhancement. In particular, among I-HCAs 7/14 showed no washout, 3/14 and 4/14 showed washout in the portal or late phase, respectively. CONCLUSIONS: This dataset represents one of the few published experiences on HCAs and CEUS in Italy and shows that HCAs are hypervascularized in the arterial phase usually with a centripetal flow pattern and have a heterogeneous behavior in portal and late phase. In particular, occurrence of delayed washout on CEUS but not on MRI is frequently observed in the subtype of I-HCA.