Real-time contrast-enhanced ultrasound imaging of focal liver lesions in fatty liver

PurposeThe objective of this study was to investigate the contrast-enhanced ultrasound (CEUS) imaging features of focal liver lesions (FLLs) in fatty liver.MethodOne hundred FLLs in 98 patients with fatty liver were evaluated with real-time CEUS.ResultsAll malignant FLLs showed hyperenhancement in arterial phase and contrast washout in portal and late phases. Among the FLLs, 3.3% of hemangiomas, 12.5% of focal nodular hyperplasias (FNHs), and 2.5% of focal fatty sparing lesions showed contrast washout in the late phase. The sensitivity and specificity for the characterization of hepatocellular carcinoma, metastasis, hemangioma, FNH, and focal fatty sparing lesions were 100% and 95.6%, 60% and 100%, 93.3% and 98.6%, 87.5% and 97.8%, and 92.6% and 100%, respectively.ConclusionsCorrect characterization of FLLs in fatty liver by CEUS is possible based on their typical enhancement patterns.     

Focal liver lesions in cirrhosis: Role of contrast-enhanced ultrasonography

Contrast-enhanced ultrasound (CEUS) represents a great innovation for the evaluation of focal liver lesions (FLLs). The main advantage of CEUS is the real-time imaging examination and the very low toxicity in patients with renal failure. Liver cirrhosis has been recognized as a major risk factor for the onset of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). HCC in liver cirrhosis develops as the last step of a complex that leads to the gradual transformation from regenerative nodule through dysplastic nodule to HCC. In patients with liver cirrhosis, a surveillance program is recommended consisting of ultrasound (US) for detecting small focal lesions. A wide spectrum of benign and malignant lesions other than HCC may be found in the cirrhotic liver and their differentiation is important to avoid errors in staging diseases that may preclude potentially curative therapies. Several published studies have explored the value of CEUS in liver cirrhosis and they have been shown to have excellent diagnostic and prognostic performances for the evaluation of non-invasive and efficient diagnosis of FLLs in patients at high risk for liver malignancies. The purpose of this article is to describe and discuss CEUS imaging findings of FLLs including HCC and ICC, all of which occur in cirrhotic livers with varying prevalence.     

Role of contrast enhanced ultrasound in characterization of focal liver lesions

Aim

The purpose of the study was to describe the enhancement patterns of focal liver lesions (FLLs) on contrast enhanced sonography (CEUS), assessing the potential of this technique for characterizing the lesions and to compare its diagnostic accuracy with conventional baseline sonography including color Doppler.

Materials and methods

Between August 2009 and July 2010, 50 patients with FLLs underwent gray scale sonography, color Doppler and CEUS. The enhancement patterns of these FLL’s were analyzed throughout the arterial phase, the portal venous phase and the extended portal venous phase (the late parenchymal phase). The final diagnosis was established on the basis of histopathologic examination or CT/MRI imaging.

Results

Out of these 50 FLLs, 33 were malignant (4 hepatocellular carcinoma and 29 metastasis) and 17 were benign (5 hemangioma, 5 abscess, 2 cyst and 1 each of FNH, focal fat sparing area, focal fatty infiltration, adenoma and benign/granulomatous lesion). The enhancement patterns after injecting microbubble contrast agent allowed characterization of FLLs. The malignant lesions showed intratumoral and/or peritumoral vascularity during the arterial phase and perfusion defect during the late parenchymal phase. Contrast enhanced sonography improved sensitivity in detecting malignancy (CEUS vs. baseline sonography, 100% vs. 81.8%).

Conclusion

CEUS improves detection and characterization of FLLs. It should be used as problem solving tool in cases where conventional gray scale and color Doppler sonography are non-diagnostic.     

Imaging features of hepatic angiomyolipomas on real-time contrast-enhanced ultrasound

The aim of this study was to evaluate the imaging features of hepatic angiomyolipoma (AML) on contrast-enhanced ultrasound (CEUS). The imaging features of 12 pathologically proven hepatic AML lesions in 10 patients who had undergone baseline ultrasound (BUS) and CEUS examinations were evaluated retrospectively. The enhancement extent, pattern and dynamic change, along with the enhancement process, on CEUS were analysed. The diagnostic results of BUS and CEUS before pathological examination were also recorded. The results showed that 75% (9/12) of the AML lesions exhibited mixed echogenicity on BUS and most showed remarkable hyperechogenicity in combination with a hypoechoic or anechoic portion. Arterial flow signals were detected in 75% (9/12) of the lesions on colour Doppler imaging. On CEUS, 66.7% (n = 8) of the 12 lesions exhibited hyperenhancement in the arterial phase, slight hyperenhancement (n = 2) or isoenhancement (n = 6) in the portal phase, and slight hyperenhancement (n = 1) or isoenhancement (n = 7) in the late phase. Three (25%) lesions exhibited hyperenhancement in the arterial phase and hypoenhancement in both portal and late phases. One (8.3%) lesion exhibited hypoenhancement throughout the CEUS process. Before pathological examination with BUS, only 3 (25%) lesions were correctly diagnosed as hepatic AML. Conversely, on CEUS, correct diagnoses were made for 66.8% (8/12) of hepatic AMLs. Therefore, arterial hyperenhancement and subsequent sustained enhancement on CEUS were found in the majority of hepatic AMLs. The combination of BUS and CEUS leads to the correct diagnosis in the majority of hepatic AMLs, and is higher than the success rate achieved by BUS alone.Hepatic angiomyolipoma (AML) is generally considered a rare benign mesenchymal tumour of the liver [1]. With the increasing clinical application of imaging, more and more hepatic AMLs are being detected [2, 3]. Baseline ultrasound (BUS) is the first-line imaging modality for liver use owing to its relatively low cost, non-invasiveness, easy manipulation and ready availability; however, its ability to characterise focal liver lesions (FLLs) cannot meet the requirement in the clinical setting [4]. The advent of the second-generation ultrasound contrast agents and contrast-specific ultrasound techniques allows depiction of the micro- and macro-circulation of FLLs, which has facilitated a great improvement in the characterisation of FLLs [5, 6]. However, until now, few reports in the literature have described the use of contrast-enhanced ultrasound (CEUS) in hepatic AML [7–11]. Herein we analyse retrospectively the imaging features of 12 hepatic AMLs on CEUS; the diagnostic results of BUS and CEUS before pathological examination are also recorded.     

Diagnostic performance of contrast-enhanced ultrasound for complex cystic focal liver lesions: blinded reader study

The study was aimed at evaluating the diagnostic performance of contrast-enhanced ultrasound (CEUS) in characterizing complex cystic focal liver lesions (FLLs). Sixty-seven complex cystic FLLs in 65 patients were examined with conventional ultrasound (US) and real-time CEUS. The US and CEUS images were reviewed by a resident radiologist and a staff radiologist independently. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance, and the interobserver agreement was analysed. The results showed that complete non-enhancement throughout three phases of CEUS or sustained enhancement in the portal and late phases were exhibited in most benign lesions. Conversely, hypo-enhancement in the late phase was seen in all malignancies. After ROC analysis, the areas (Az) under the ROC curve were 0.774 at US versus 0.922 at CEUS (P = 0.047) by the resident radiologist, and 0.917 versus 0.935 (P = 0.38) by the staff radiologist. A significant difference in Az between the resident and the staff radiologists was found for US (0.774 versus 0.917, P = 0.044), whereas not found for CEUS (0.922 versus 0.935, P = 0.42). Interobserver agreement was improved after CEUS (κ = 0.325 at US versus κ = 0.774 at CEUS). Real-time CEUS improves the capability of discrimination between benign and malignant complex cystic FLLs, especially for the resident radiologist.     

Characterization of focal liver lesions with a new ultrasound contrast agent using continuous low acoustic power imaging: comparison with contrast enhanced spiral CT

PURPOSE: To evaluate the concordance of the enhancement patterns of a new ultrasound contrast agent (SonoVue) with those obtained with dual-phase contrast-enhanced spiral CT (CE-CT) in the characterization of focal liver lesions (FLLs). MATERIALS AND METHODS: Sixty-two patients with focal liver lesions discovered at ultrasound and also studied with CECT underwent contrast-enhanced ultrasound using continuous low acoustic power imaging after receiving a 2.4 ml bolus of the new US contrast agent SonoVue, consisting of a dispersion of sulphur hexafluoride microbubbles. The examinations were made using ATL HDI-5000, Acuson SEQUOIA and Aloka 5500 Prosound ultrasound systems with 5.2 MHz curved-array probes. The concordance between US and CE-CT images was evaluated on site by two radiologists blinded to CT RESULTS: The FLLs were assessed in the arterial (20 s after CM injection), portal (after 45-60 s) and late (after 120 s) phases for: 1) presence/absence of enhancement 2) distribution of enhancement (homogenous or target distribution, centripetal or centrifugal flow, and other), 3) qualitative enhancement pattern (hyperechoic, hypoechoic, or isoechoic) versus normal liver parenchyma. RESULTS: The concordance between SonoVue-enhanced US and CE-CT was 85%. Moreover during portal venous phase with CEUS it was possible to differentiate between malignancy or benignity of 91% of lesions. CONCLUSIONS: The preliminary data obtained in this study suggest that continuous low acoustic power imaging and contrast-enhanced US show similar results to CT in contrast distribution and contrast enhancement patterns.     

Computer-aided diagnosis for contrast-enhanced ultrasound in the liver

Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. The basic concept of CAD is to provide computer output as a second opinion to assist radiologists' image interpretations by improving the accuracy and consistency of radiologic diagnosis and also by reducing the image-reading time. To date, research on CAD in ultrasound (US)-based diagnosis has been carried out mostly for breast lesions and has been limited in the fields of gastroenterology and hepatology, with most studies being conducted using B-mode US images. Two CAD schemes with contrast-enhanced US (CEUS) that are used in classifying focal liver lesions (FLLs) as liver metastasis, hemangioma, or three histologically differentiated types of hepatocellular carcinoma (HCC) are introduced in this article: one is based on physicians' subjective pattern classifications (subjective analysis) and the other is a computerized scheme for classification of FLLs (quantitative analysis). Classification accuracies for FLLs for each CAD scheme were 84.8% and 88.5% for metastasis, 93.3% and 93.8% for hemangioma, and 98.6% and 86.9% for all HCCs, respectively. In addition, the classification accuracies for histologic differentiation of HCCs were 65.2% and 79.2% for well-differentiated HCCs, 41.7% and 50.0% for moderately differentiated HCCs, and 80.0% and 77.8% for poorly differentiated HCCs, respectively. There are a number of issues concerning the clinical application of CAD for CEUS, however, it is likely that CAD for CEUS of the liver will make great progress in the future.     

Detection and characterization of focal liver lesions with contrast-enhanced ultrasonography in patients with hepatitis C-induced liver cirrhosis

Background: Hepatitis C virus (HCV)-associated liver cirrhosis provides a major preneoplastic condition for hepatocellular carcinoma (HCC). Ultrasonography (US) is usually used for screening of HCC, but needs improvement.

Purpose: To assess whether use of a second-generation ultrasound contrast agent can improve characterization of focal liver lesions and detection of HCC in HCV-infected patients with liver cirrhosis.

Material and Methods: In total, 96 US studies in 49 HCV-infected patients with liver cirrhosis were performed. The patients were first examined with a baseline US. After this, a diagnostic decision was made and recorded. The patients were then re-examined with contrast-enhanced ultrasound (CEUS), and the diagnostic triage was repeated. The patients were followed up for at least 1 year.

Results: On baseline US, indeterminate focal lesions were found in 27 examinations. After CEUS, a confident diagnosis of HCC was made in eight of these examinations. In an additional eight US examinations, diagnosis of regenerative/dysplastic noduli was established. In one patient with no detectable focal lesion at baseline examination, an indeterminate malignant lesion was detected with CEUS. This lesion was further investigated with computed tomography and diagnosed as HCC.

Conclusion: Our study indicates that the use of CEUS significantly improves diagnostic confidence. CEUS improves the detection of HCC in patients with HCV-induced liver cirrhosis. Also, CEUS makes it possible to rule out malignancy in many cases where baseline US shows indeterminate focal lesions. In low-endemic countries, the use of CEUS in screening for HCC may be considered.     

超声造影在移植肝脏局灶性低回声病灶鉴别诊断中的应用

 目的 评价超声造影技术在肝移植术后肝脏局灶性低回声病灶鉴别诊断中的应用价值.方法 对肝移植术后肝脏出现局灶性低回声病灶患者,用西门子 Sequoia512彩色多普勒超声诊断仪和超声造影剂Sonovue进行超声造影检查,观察3个时相的造影剂灌注模式,并用自动跟踪对比量化技术(Axius ACQ)对病灶及周围肝组织进行定量分析.结果 10例出现局灶性低回声病灶的患者中,超声造影明确诊断梗死灶5例(低回声病灶为无增强,ACQ分析无造影剂灌注),非均质脂肪肝3例(低回声病灶在动脉相、门脉相呈高增强,ACQ分析该区域为正常肝组织,周围肝组织为血流灌注不良区域),肝癌复发2例(其特征为动脉相快速均匀高增强,门脉相及延迟相快速消退).结论 超声造影技术能较好评估肝实质的血流灌注分布情况,有助于移植肝脏梗死灶、非均质性脂肪肝及肿瘤复发的鉴别诊断.     

Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions

The extensive use of imaging techniques in differential diagnosis of abdominal conditions and screening of hepatocellular carcinoma in patients with chronic hepatic diseases, has led to an important increase in identification of focal liver lesions. The development of contrast-enhanced ultrasound (CEUS) opens a new window in the diagnosis and follow-up of these lesions. This technique offers obvious advantages over the computed tomography and magnetic resonance, without a decrease in its sensitivity and specificity. The new second generation contrast agents, due to their intravascular distribution, allow a continuous evaluation of the enhancement pattern, which is crucial in characterization of liver lesions. The dual blood supply in the liver shows three different phases, namely arterial, portal and late phases. The enhancement during portal and late phases can give important information about the lesion's behavior. Each liver lesion has a different enhancement pattern that makes possible an accurate approach to their diagnosis. The role of emerging techniques as a contrast-enhanced three-dimensional US is also discussed. In this article, the advantages, indications and technique employed during CEUS and the different enhancement patterns of most benign and malignant focal liver lesions are discussed.     

超声造影鉴别肝脏局灶性病变良恶性的临床意义

目的评价超声造影技术在鉴别良恶性肝脏局灶性病变中的临床意义,并与常规超声比较。方法 83例经穿刺活检及手术或临床证实的肝脏局灶性病变(38例恶性和45例良性)均经常规超声和超声造影检查,对肝脏局灶性病变在造影检查中的强化型式与时相特征逐例进行了观察与记录,并用卡方检验比较了两种方法对肝脏局灶性病变的诊断效能。结果肝脏局灶性病变随其良性与恶性而表现为不同的强化型式与时相特征。超声造影正确诊断34例恶性和43例良性病变,其诊断敏感性、特异性和准确性分别为89.5%、95.6%和92.8%,而常规超声正确诊断23例恶性和22例良性病变,其诊断敏感性、特异性和准确性分别为60.5%、48.9%和54.2%。两种方法诊断效能比较有统计学差异(P<0.01)。结论超声造影技术在肝脏局灶性病变良恶性鉴别诊断中具有重要的临床应用价值,并可取代常规超声。     

肝癌多期动态CT强化特点与PTEN表达的相关性研究

目的:探讨肝癌多期动态CT强化特点及其与抑癌基因PTEN表达的相关性。方法:选择肝细胞癌患者99例行CT扫描,增强扫描包括动脉期早期、动脉晚期、静脉期及延迟期。于后处理工作站分析CT数据,并通过多平面重组、容积再现及最大密度投影观察病变特点,分析肝癌包膜及门静脉癌栓与肝癌内PTEN表达的关系。结果:①动脉晚期对<3cm肝癌病灶的显示率明显高于其他2期(P<0.05)。各期对≥3cm肝癌病灶显示率差异无统计学意义(P>0.05)。②有完整包膜的肝癌患者中PTEN阳性28例(75.68%),明显高于包膜不完整及无包膜的肝癌患者(P<0.05),PTEN蛋白的表达与肝癌完整包膜间呈正相关。不伴有门静脉癌栓的肝癌患者中PTEN阳性25例(75.76%),明显高于伴有门静脉癌栓的肝癌患者(P<0.05),PTEN蛋白的表达与门静脉癌栓呈负相关。结论:多期动态螺旋CT扫描对肝细胞癌具有很高的检出率,且肝癌包膜的完整性及门静脉癌栓的有无与PTEN表达存在相关性。     

Evaluation of hepatocellular carcinoma using SonoVue,a second generation ultrasound contrast agent: correlation with cellular differentiation

The appearance of hepatocellular carcinoma (HCC) with contrast-enhanced ultrasound (CEUS) in the vascular phase is described and evaluated as to whether the enhancement pattern correlates with the degree of cellular differentiation. One hundred four HCCs were prospectively evaluated with CEUS using coherent-contrast imaging (CCI) and SonoVue with a low mechanical index (<0.2). The enhancement of HCCs in the vascular phase was analyzed according to the degree of pathological differentiation obtained by fine-needle biopsy. In the arterial phase, all HCCs except for four well differentiated ones (96.2%) showed enhancement (P<0.05). Histological differentiation of hypoechoic lesions in the early portal phase (7 HCCs; 16%) significantly differed from hyperechoic (1 HCC; 1%) or isoechoic lesions (87 HCCs; 83.6%) (P<0.05), with a significant probability of a worse differentiation in hypoechoic lesions. Histological differentiation of isoechoic lesions in the late phase (30 HCCs; 28.8%) significantly differed from hypoechoic lesions (74 HCCs; 71.2%) (P<0.05), with a significant probability of a better differentiation in isoechoic lesions. CEUS using CCI and SonoVue revealed enhancement in the arterial phase in >95% of HCCs, with a few well-differentiated cases not being diagnosed due to the absence of enhancement. Echogenicity in the portal and late phases correlated with cellular differentiation.     

Does the echogenicity of focal liver lesions on baseline gray-scale ultrasound interfere with the diagnostic performance of contrast-enhanced ultrasound?

The objective was to evaluate whether the echogenicity of focal liver lesions (FLLs) on baseline gray-scale ultrasound (US) interferes with the diagnostic performance of contrast-enhanced US (CEUS) for small FLLs. Three-hundred and eighty-eight patients were examined by real-time CEUS using a sulfur hexafluoride-filled microbubble contrast agent. The images of 114 hyperechoic lesions, 30 isoechoic lesions and 244 hypoechoic lesions were reviewed by two blinded independent readers. A five-point confidence level was used to discriminate malignant from benign lesions, and specific diagnoses were made. The diagnostic performances were evaluated by receiver-operating characteristic (ROC) analysis. The diagnostic performances of CEUS on hyperechoic lesions in terms of the areas (Az) under the ROC curve were 0.987 (reader 1) and 0.981 (reader 2), and were 0.987 (reader 1) and 0.984 (reader 2) for iso- and hypoechoic lesions, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.0–95.9%, 93.1–100%, 88.6–100%, 70.0–97.1% and 90.0–95.1%, respectively. The echogenicity of FLLs on baseline gray-scale US does not appear to interfere with the diagnostic ability of CEUS for small FLLs.     

小转移性肝癌的超声造影表现及其应用价值

目的：观察小于3cm的恶性肿瘤肝转移病灶的超声造影表现并探讨其临床应用价值。方法：对77例已确诊为恶性肿瘤肝转移的患者进行Sono Vue超声造影检查,记录并分析不同大小病灶的造影后各时相增强的特征。结果：大小〈1.0cm的4例病灶,动脉相均表现为整体团状增强;大小为〉1.0cm～≤2.0cm的39例病灶中,动脉相整体团状增强18例,环状增强17例,不均匀整体增强2例,无增强2例;大小为〉2.0cm～≤3.0cm的34例病灶中,动脉相整体团状增强6例,环状增强24例,不均匀整体增强3例,等增强1例。病灶大小与增强模式之间比较有统计学意义（P〈0.01）。结论：在小转移性肝癌中,病灶的增强模式与大小有关;超声造影对恶性肿瘤临床分期及治疗方案的选择有重要的应用价值。     

Correlation between enhancement pattern of hepatocellular carcinoma on real-time contrast-enhanced ultrasound and tumour cellular differentiation on histopathology

The objective of this study was to evaluate the correlation between the enhancement pattern of hepatocellular carcinoma (HCC) on contrast-enhanced ultrasound (CEUS) and tumour cellular differentiation on histopathology. 189 HCC lesions in 189 patients were retrospectively evaluated with CEUS and histopathological examination. CEUS was performed with SonoVue and contrast pulse sequencing. Histopathological diagnoses were made according to the Edmonson grading system. Significant differences were shown between the time that the HCC became hypoenhancing or remained echogenic in late phase and tumour cellular differentiation (p = 0.006; p = 0.036), but not with the time of commencement of hyperenhancing or commencement of isoenhancing in arterial phase and portal phase (p = 0.164, p = 0.113; p = 0.186, p = 0.070). The timing of HCC becoming hypoenhancing on CEUS is correlated with tumour cellular differentiation; well differentiated tumours wash out more slowly than poorly differentiated ones.     

Focal liver lesions: can SonoVue-enhanced ultrasound be used to differentiate malignant from benign lesions?

OBJECTIVE: To evaluate whether contrast-enhanced ultrasound (CEUS) with SonoVue could differentiate malignant focal liver lesions (FLLs) from benign lesions and provide lesion type diagnoses. MATERIALS AND METHODS: Four hundred fifty-six patients with 554 FLLs were examined by CEUS with SonoVue using low mechanical index, nonlinear imaging techniques. Each lesion was characterized by 2 independent off-site readers as malignant or benign and given specific lesion type diagnosis, if possible, both at baseline ultrasound (US) and after SonoVue administration (CEUS). The final diagnosis was achieved by histopathology obtained from biopsy or surgical specimens, or by typical manifestation on contrast-enhanced CT or MRI. RESULTS: The diagnostic accuracies of the 2 readers were 41.9% and 35.2% for baseline US, which improved significantly to 87.2% and 87.9% for CEUS (P < 0.05). Interreader agreement also increased with CEUS compared with baseline US (ê value changed from 0.49 to 0.77). The accuracy for lesion type diagnosis was 38.4% and 32.5% for baseline US, which increased to 77.6% and 78.0% for CEUS (P < 0.05). CONCLUSIONS: CEUS with SonoVue improves differentiation between malignant and benign FLLs, and also provides improved lesion type (differential) diagnosis.     

Nachweis und Charakterisierung von Lebermetastasen

Since the advent of second generation ultrasound (US) contrast agents, ultrasound has caught up with other imaging modalities for the detection and characterization of liver metastases and as a result of its high temporal and spatial resolution it can in some cases even be superior to computed tomography (CT) and magnetic resonance imaging (MRI). Many studies have demonstrated a sensitivity and specificity of over 90%. Due to its high temporal resolution contrast-enhanced US (CEUS) is capable of detecting even a very short duration of hyper-enhancement during the arterial phase. Radiation protection and lack of adverse effects on renal or thyroid function are additional arguments why CEUS should be recommended as the first imaging modality in the evaluation of hepatic metastases in cases of favorable scanning conditions.     

Evaluation of pathological features of hepatocellular carcinoma by contrast-enhanced ultrasonography: comparison with pathology on resected specimen

Features of hepatocellular carcinoma (HCC) observed by contrast-enhanced ultrasonography (CEUS) were compared to pathological features of corresponding resected HCC specimens, to evaluate the ability of CEUS to depict the pathological features of HCC. We investigated 50 HCC nodules that were treated by surgical resection. All nodules had been examined by CEUS with intravenous contrast agent (Levovist) before surgery. CEUS findings were divided into three phases for evaluation and classification of enhancement patterns: two vascular phases (arterial phase and portal venous phase) and the delayed phase. Pathological examination focused on differentiation and on the presence or absence of a tumor capsule, intratumoral septum, and intratumoral necrosis. All 21 nodules that showed a linear or annular vessel around the tumor margin in the arterial phase had capsular formation. Of the 27 nodules that showed heterogeneous perfusion in the portal venous phase, 21 (77.8%) had an intratumoral septum and 23 (85.2%) showed intratumoral necrosis. All nodules that were depicted as a defect with an unclear margin in the delayed phase were well-differentiated HCCs, whereas all nodules that were depicted as a defect with a clear margin were moderately or poorly differentiated HCCs. From our observations, the arterial, portal venous, and delayed phases of CEUS could reflect different pathological aspects of HCC. Some pathological characteristics of HCC might be evaluated preoperatively and non-invasively, by means of combined analysis of three phases of CEUS findings.     

Quantification of enhancement of focal liver lesions during contrast-enhanced ultrasound (CEUS). Analysis of ten selected frames is more simple but as reliable as the analysis of the entire loop for most parameters

The aim of the study was to evaluate the reliability of the analysis of only 10 frames rather than of a whole clip in performing quantitative assessment of tumor enhancement of focal liver lesions (FLLs) following ultrasound contrast injection. Contrast-enhanced ultrasonography (CEUS) examinations of 31 FLLs (median diameter: 30mm) were performed. All clips were analyzed and quantified with an early prototype of the SonoLiver software (TomTec GmbH, Munich and Bracco Research SA, Geneva), first evaluating the entire clip then selecting only 10 frames at different time intervals. Enhancement measurements obtained from the analysis of the entire clip or of only 10 frames were closely correlated (r=0.931 and p<0.0001 for Area Under the Curve; r=0.944 and p<0.0001 for Perfusion Index). In conclusion, enhancement quantification of FLLs can be reliably obtained from only 10 frames, rather than the entire clip, at least for most parameters, making such procedure easier for potential routine use.