Hypoechoic focal liver lesions: characterization with contrast enhanced ultrasonography

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.

Limited added value of contrast-enhanced ultrasound over B-mode for the subtyping of hepatocellular adenomas

PURPOSE

To compare the features of hepatocellular adenoma subtypes (HCAs) in B-mode and contrast-enhanced ultrasound (CEUS).

METHOD

Thirty-three patients (31 women [94 %] and two men [6%], median age [Q1-Q3] 43.5 years old [35-51]) with 44 pathologically proven and subtyped HCAs (including 29 inflammatory HCAs [I-HCA] and 15 HNF1-α inactivated HCAs [H-HCA]) who underwent CEUS were included. The features of HCA on B-mode and CEUS were independently reviewed by two radiologists and compared between HCA subtypes.

RESULTS

I-HCAs were mostly hypoechoic (23/29, 79 %) or isoechoic (4/29, 14 %) with B-mode. Twelve of them (41 %) were heterogeneous. All H-HCAs except one demonstrated homogeneous hyperechogenicity (93 %) (p = 0.001). Moderate or marked liver steatosis was only observed in I-HCAs (12/29, 41 %) (p = 0.001). Arterial hyperenhancement was observed on CEUS in 27/29 (93 %) I-HCAs and in 14/15 (93 %) H-HCAs (p=0.98). Washout was present in 6/29 (21 %) I-HCAs and 1/15 (7%) H-HCAs (p=0.27). A total of 23/29 (79 %) I-HCAs and 15/15 (100 %) HCAs were homogeneous on portal and delayed phase acquisitions (p=0.04). The specificity for identifying an H-HCA was 100 % when the lesion was homogeneous and hyperechoic on B-mode, and the sensibility to rule out an H-HCA was 100 % if neither of these two features was present in a liver with obvious steatosis.

CONCLUSIONS

Most CEUS features, especially enhancement patterns, do not significantly differ between HCA subtypes. When HCA is suspected on CEUS, B-mode features should be considered, and a combination of lesion hyperechogenicity, homogeneity and the absence of obvious liver steatosis may be useful to distinguish H-HCAs from I-HCAs.

Diagnosis efficacy of CEUS for hepatic inflammatory lesions

Purpose

In this study, the efficacy of US/CEUS and clinicopathologic parameters in differential diagnosis of hepatic inflammatory lesions were evaluated.

Methods

This was a retrospective study in which CEUS imaging was performed on 182 patients. Among these patients, 44 patients had hepatic inflammatory lesions and 138 patients had malignant lesions. The ultrasound (US), CEUS, and clinicopathologic parameters with respect to differential diagnosis of hepatic inflammatory lesions were analyzed.

Results

Irregular lesion shape and unclear margin were commonly seen in hepatic inflammatory lesions by US/CEUS examination. Hypoenhancement in arterial phase (AP) and portal venous phase (PVP), and isoenhancement in delayed phase (DP) were more commonly found in inflammatory lesions rather than malignant lesions [9% (4/44), 68% (30/44), and 16% (7/44) vs 2% (3/138), 11% (15/138), 1% (1/138), respectively; P < .05]. The enhancement coverage was also a significant indicator for the differentiation of inflammatory lesions and malignant lesions (P < .05). History of hepatitis or cirrhosis, and higher serum alpha‐fetoprotein (AFP) level were indicators for malignant lesions, while liver parasites and higher body temperature were indicators for inflammatory lesions. When the US/CEUS findings were combined with clinicopathologic parameters, the diagnostic accuracy of inflammatory lesions could reach 93.3%, with sensitivity, specificity, positive predictive value, and negative predictive value of 63.64%, 96.03%, 84.85%, and 88.32%, respectively.

Conclusion

The US/CEUS findings combined with clinical characteristics can accurately differentiate hepatic inflammatory lesions and malignant lesions. The results of study will improve the diagnostic confidence for hepatic inflammatory lesions.

Clinical use of contrast-enhanced ultrasound beyond the liver: a focus on renal, splenic, and pancreatic applications

Contrast-enhanced ultrasound (CEUS) is a relatively novel, but increasingly used, diagnostic imaging modality. In recent years, due to its safety, quickness, and repeatability, several studies have demonstrated the accuracy, specificity, and sensitivity of CEUS. The European Federation of Societies for Ultrasound in Medicine and Biology has recently updated the previous guidelines from 2012 for the use of CEUS in non-hepatic applications. This review deals with the clinical use and applications of CEUS for the evaluation of non-hepatic abdominal organs, focusing on renal, splenic, and pancreatic applications.

Nodular focal fat sparing of liver mimicking hepatocellular carcinoma in contrast-enhanced ultrasound: A case report

INTRODUCTION

Focal fatty sparing is a manifestation of fatty liver. Nodular focal fatty sparing of liver sometimes is a mimicker of malignant lesion, especially metastatic tumor. There are some case reports about this kind of tricks revealed by computed tomography (CT) and magnetic resonance imaging. However, few reports described nodular focal sparing of liver presenting an enhancement mode of hepatocellular carcinoma (HCC) in contrast-enhanced ultrasound (CEUS).

PATIENT CONCERNS

A 37-year-old male had a long history of alcohol abuse and hepatitis B virus infection. Routine blood examination showed an elevation of triglyceride, and tumor markers were unremarkable. Conventional ultrasound indicated a diffuse fatty liver with a hypoechoic nodular lesion. CEUS revealed hyperenhancement in arterial phase and washout in late phase of this hypoechoic lesion. Contrast-enhanced CT showed a similar enhancement mode of the mass with CEUS.

DIAGNOSIS

A clinical diagnosis of HCC was made. Then, liver resection was conducted. Postoperative histopathologic and immunohistochemical results of the lesion revealed no presence of tumor cells except for heterogeneous hepatic steatosis. So a final diagnosis of hepatic focal fatty sparing was determined.

INTERVENTIONS

Liver resection was conducted according to the clinical diagnosis of HCC.

OUTCOMES

After general postoperative administration, the patient was told to discharge. Then, he had been undergoing regular serological tests and imaging examinations in our hospital for 39 months and found no manifestation of liver tumor.

CONCLUSION

According to guidelines, it is typical that hepatic focal fatty change (FFC) presents a mode of persistent iso-enhancement in CEUS. However, atypical enhancement presence of FFC in imaging examinations may occur and lead to misdiagnosis, which calls for more attention.

Contrast-enhanced ultrasound of malignant liver lesions

Contrast-enhanced ultrasound (CEUS) is a safe, relatively inexpensive, and widely available imaging technique using dedicated imaging ultrasound sequences and FDA-approved contrast microbubbles that allow detection and characterization of malignant focal liver lesions with high diagnostic accuracy. CEUS provides dynamic real-time imaging with high spatial and temporal capability, allowing for unique contributions to the already established protocols for diagnosing focal liver lesions using CT and MR imaging. In patients with lesions indeterminate on CT and MRI, CEUS is a helpful problem-solving complementary tool that improves patient management. Furthermore, CEUS assists guidance of liver biopsies and local treatment. Variations of CEUS such as DCE-US and ultrasound molecular imaging are emerging for quantitative monitoring of treatment effects and possible earlier detection of cancer. In this review, basic principles of CEUS techniques and ultrasound contrast agents along with a description of the enhancement patterns of malignant liver lesions are summarized. Also, a discussion of the role of CEUS for treatment guidance and monitoring, intraoperative CEUS, and an outlook on emerging applications is provided.

Impact of tumor size and cirrhotic background for differentiating HCC and ICC with CEUS: does it matter for patients undergoing hepatectomy?

OBJECTIVES

The aim of this study was to investigate the role of contrast-enhanced ultrasound (CEUS) in differentiating hepatocellular carcinoma (HCC) vs. intrahepatic cholangiocarcinoma (ICC) and primary liver cancer vs. benign liver lesions for surgical decision making.

METHODS

Data from 328 patients (296 primary liver cancer patients: 232 HCC and 64 ICC patients and 32 benign hepatic lesion patients) who underwent hepatectomy at our center were retrospectively collected from 2010 to 2015. Conventional ultrasound (US) and CEUS were performed for all patients before hepatectomy. Enhancement patterns in CEUS were classified and compared for HCC vs. ICC and for primary liver cancer vs. benign lesions.

RESULTS

Primary liver cancer and hepatic benign lesions could be distinguished by CEUS in different phases. The most obvious differences were in the portal and delayed phases, in which benign lesions could still show hyperenhancement (46.9% vs. 0.0% and p < 0.001 in the portal phase; 43.7% vs. 0.0% and p < 0.001 in the delayed phase). For differentiating HCC and ICC, our results revealed that HCC and ICC displayed different enhancement patterns in the arterial phase (p < 0.001) and the portal phase (p < 0.001). In the subgroup analyses, both HCC and ICC showed a high rate of homogeneous hyperenhancement during the arterial phase when tumors were ≤5 cm (87.2% vs. 64.0% and p = 0.008) or the Ishak score was ≥5 (75.8% vs. 42.9% and p = 0.023), although there was statistical difference. However, during the portal phase, ICC > 5 cm showed significantly more frequent hypoenhancement (92.3% vs. 54.5% and p < 0.001) and less isoenhancement (7.7% vs. 45.5% and p < 0.001) than HCC; additionally, during the portal phase, there was no statistical difference in the enhancement patterns of ICC with different hepatic backgrounds.

CONCLUSIONS

Tumor size and hepatic background should be taken into consideration when distinguishing HCC and ICC before surgery. However, CEUS is a helpful tool for differentiating malignant and benign hepatic lesions. For patients who require surgical treatment, CEUS may help with surgical decision making.

Contrast-enhanced ultrasound of pancreatic tumours

Indication/purpose: To review contrast‐enhanced ultrasound features of the most common pancreatic tumours.

Methods: Contrast‐enhanced ultrasound (CEUS) can provide distinctive features of pancreatic tumours that are reported in the present paper, providing radiologic‐pathological correlations and clarifying the main differential diagnosis.

Conclusion: Contrast‐enhanced ultrasound plays a well‐established role in the evaluation of pancreatic tumours. When possible, CEUS should be always performed after the initial US diagnosis, in order to improve the accuracy of the first line examination.

Contrast enhancement ultrasound application in focal liver lesions characterization: a retrospective study about guidelines application (SOCEUS-CEUS survey)

INTRODUCTION

The SOCEUS survey aims to evaluate how contrast-enhanced ultrasound (CEUS) is effectively used in the focal liver lesions characterization.

MATERIALS AND METHODS

In the survey were involved Verona, Brescia and Trieste Radiological Centers and Arezzo and Bologna Non-radiological Centers. Inclusion criteria were liver focal lesion detection at conventional ultrasound and studied by means of CEUS, with or without CT or MRI examinations, done previous or subsequent to CEUS.

RESULTS

1069 forms were collected. Patients with benign lesions, who did not undergo any other studies, were 255/561 (45.5 %). Among patients with diagnosis of hemangioma at CEUS, those who had no other investigations were 129/267 (48.3 %). Patients with malignant lesions who had studies pre-CEUS (CT and/or MRI) were 328/508 (65 %), whereas those who had examinations post-CEUS (CT and/or MRI) were 218/508 (42.9 %). Concordance rate between CEUS and CT investigations pre- and post-CEUS was, respectively, 66 and 89 %. Concordance rate between CEUS and MRI studies pre- and post-CEUS was, respectively, 87.5 and 81.5 %.

CONCLUSION

This study proves contrast-enhanced ultrasound correct application in the involved centers.

CEUS of the pancreas: Still research or the standard of care

Contrast-enhanced ultrasonography (CEUS) improves the characterization of pancreatic masses. CEUS is in fact a safe and accurate imaging method to evaluate the vascularity of pancreatic lesions. CEUS should be performed when possible immediately after the ultrasound (US) detection of a pancreatic mass. CEUS is accurate in the characterization of ductal adenocarcinoma. The use of CEUS in studying pancreatic lesions found at US, especially in the same session of ultrasound examination, is therefore recommendable to promote faster diagnosis mainly of pancreatic ductal adenocarcinoma.

Malignant focal liver lesions at contrast-enhanced ultrasonography and magnetic resonance with hepatospecific contrast agent

The aim of this study was to compare the diagnostic accuracy of the late phase of CEUS and the hepatobiliary phase of CE-MR with Gd-BOPTA in the characterization of focal liver lesions in terms of benignity and malignancy. A total of 147 solid focal liver lesions (38 focal nodular hyperplasias, 1 area of focal steatosis, 3 regenerative nodules, 8 adenomas, 11 cholangiocarcinomas, 36 hepatocellular carcinomas and 49 metastases) were retrospectively evaluated in a multicentre study, both with CEUS, using sulphur hexafluoride microbubbles (SonoVue, Bracco, Milan, Italy) and CE-MR, performed with Gd-BOPTA (Multihance, Bracco, Milan, Italy). All lesions thought to be malignant were cytohistologically proven, while all lesions thought to be benign were followed up. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and accuracy were calculated for the late phase of CEUS and the hepatobiliary phase of CE-MRI, respectively, and in combination. Analysis of data revealed 42 benign and 105 malignant focal liver lesions. We postulated that all hypoechoic/hypointense lesions on the two phases were malignant. The diagnostic errors were 13/147 (8.8%) by CEUS and 12/147 (8.2%) by CE-MR. Sensitivity, specificity, PPV, NPV and accuracy of the late phase of CEUS were 90%, 93%, 97%, 80% and 91%, 93%, 97%, 81% and 92% for the hepatobiliary phase of CE-MRI, respectively. If we considered both techniques, the misdiagnosis diminished to 3/147 (2%) and sensitivity, specificity, PPV, NPV and accuracy were 98%, 98%, 99%, 95% and 98%. The combination of the late phase of CEUS and the hepatobiliary phase of CE-MR in the characterization of solid focal liver lesions in terms of benignity and malignancy is more accurate than the two techniques used separately.

Contrast-Enhanced Ultrasound for the differentiation of benign and malignant focal liver lesions: a meta-analysis

BACKGROUND

International guidelines of Ultrasound recommend the performance of contrast-enhanced ultrasound (CEUS) as the first method of choice after conventional ultrasound for the diagnostic work-up of focal liver lesions. However, these recommendations are based on the results of multiple single studies and only few large multicentre studies.

AIMS

The rationale of the present systematic review and meta-analysis was to assess the overall sensitivity and specificity of CEUS for the diagnosis of malignant liver lesions.

METHODS

Literature databases were searched up to March 2012. Inclusion criteria were evaluation of CEUS, assessment of sensitivity and specificity of CEUS for the diagnosis of malignant liver lesions. The meta-analysis was performed using the random-effects model based on the DerSimonian Laird method. Quality analyses were carried out to assess sources of heterogeneity.

RESULTS

A total of 45 studies with 8147 focal liver lesions were included in the analysis. Overall sensitivity and specificity of CEUS for the diagnosis of malignant liver lesions was 93% (95%-CI: 91-95%) and 90% (95%-CI: 88-92%) respectively. Significant heterogeneity was found between studies. However, subanalysis revealed no significant difference when evaluating studies using histology for all liver lesions, when comparing high-quality and low-quality studies, and blinded vs non-blinded studies.

CONCLUSION

The results of this meta-analysis support the international recommendations on CEUS for the diagnostic work-up of focal liver lesions selecting patients who need further diagnostics.

Source and clinical motivation of orders for contrast-enhanced sonography (CEUS) of the liver: A prospective single-center survey

Contrast-enhanced sonography (CEUS) has become a routine part of diagnostic imaging of the liver. Its possibilities, limitations, and indications have been defined in adequately large clinical series and in guidelines and recommendations. We prospectively evaluated physicians' orders for hepatic CEUS received in the radiology department of a large oncology center in Naples, Italy from May 2009 to April 2010. Radiologists performing the CEUS examinations filled out a form that included patient demography, source and type of patient referral, and clinical indications for the examination. During the study period, 564 patients aged 17-86 years (mean, 58 years) were referred to our department for CEUS liver studies (total: 644; 491 outpatient studies, 153 inpatient studies). This included 4 examinations that were ordered by the patient's physician but not performed by our staff. The majority of the CEUS examinations (n = 583; 90.5%) were regularly scheduled procedures ordered by clinical specialists from our center (77.3%) or other centers (11.8%); by general practitioners (on their own initiative) (0.8%); or by other figures (0.6%). The remaining 61 examinations (9.5%) were unscheduled procedures done on the initiative of a radiologist following conventional sonography (US). Fewer than half (47.8%) of the examinations were requested as first-line assessments. The others were ordered to clarify inconclusive findings generated by conventional US (30%) or by a more sophisticated imaging study (CT, MRI, PET) (16.1%) or to resolve discrepancies between CT, MRI, and/or PET findings (6%). CEUS is a relatively noninvasive, low-cost imaging study that is simple to perform and requires no particular patient preparation. This may explain its increasing use to clarify doubts raised by conventional US and other more sophisticated imaging studies.

Contrast-enhanced ultrasonography in evaluating hepatic metastases from neuroendocrine tumours

OBJECTIVES

At presentation, gastroenteropancreatic neuroendocrine tumours (GEP NETs) frequently show prognostically negative hepatic involvement. The aim of this study was to characterise hepatic metastases of GEP NETs as revealed by contrast-enhanced ultrasonography (CEUS), which allows the fine definition of the microvascular system, and to correlate these findings to the biological behaviour of the tumour.

METHODS

Eighteen out of 62 GEP NET patients examined between January 2007 and September 2008 had histologically proven hepatic metastases from primary ileal (#6), gastric (#1) or rectal (#1) carcinoids, pancreatic tumours (#7), or primary duodenal (#2) or occult gastrinomas (#1), and all underwent low mechanical index real-time CEUS with SonoVue injection.

RESULTS

Strong early enhancement in the arterial phase was observed in 15 cases (83%), and a rapid wash-out in the portal venous phase in 14 (78%). In the late venous phase, the lesions were hypoechoic in 12 cases (67%), isoechoic in five (28%), and hyperechoic in one (0.05%). The time of arterial enhancement correlated with the Ki-67 proliferative index (r(s)=0.516; p=0.028).

CONCLUSIONS

Most of the neuroendocrine liver metastases showed increased arterial enhancement at CEUS, a behaviour that is similar to that of hepatocellular carcinomas and the opposite of that of other metastases. CEUS can be a useful diagnostic means of characterising such metastases.

Differentiation of focal liver lesions using three-dimensional ultrasonography: Retrospective and prospective studies

AIM: To differentiate focal liver lesions based on enhancement patterns using three-dimensional ultrasonography (3D US) with perflubutane-based contrast agent.

METHODS: Two hundred and eighty two patients with focal liver lesions, including 168 hepatocellular carcinomas (HCCs), 63 metastases, 40 hemangiomas and 11 focal nodular hyperplasias (FNHs), were examined by 3D US with perflubutane-based contrast agent. Tomographic ultrasound images and sonographic angiograms were reconstructed. Among 282 lesions, enhancement patterns of 163 lesions between January 2007 and October 2007 were analyzed retrospectively. Then from November 2007 to May 2008, compared with contrast-enhanced (CE) 2D US, CE 3D US was performed on 119 lesions for prospective differential diagnosis. Sensitivity, specificity, area under receiver operating characteristic curve (A_z) and inter-reader agreement were assessed.

RESULTS: With the tridimensional view, dominant enhancement patterns were revealed as diffuse enhancement or peripheral ring-like enhancement, followed with washout change for HCCs or metastases, respectively, and peripheral nodular enhancement or diffuse enhancement with spoke-wheel arteries, followed by persistent enhancement for hemangiomas or FNHs, respectively. At CE 3D US, the prospective differentiation of lesions showed sensitivity 92% (mean for two readers), specificity 91% and A_z value 0.95 for HCCs, 84%, 97%, and 0.95 for metastases, 91%, 98%, and 0.98 for hemangiomas and 80%, 99%, and 0.99 for FNHs, respectively, while good to excellent inter-reader agreement was achieved. No significant difference exists between prospective diagnosis accuracy at CE 3D US and that at CE 2D US.

CONCLUSION: CE 3D US provides a spatial perspective for liver tumor enhancement, and could help in differentiating focal liver lesions.

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.

Enhancement patterns of intrahepatic cholangiocarcinoma: comparison between contrast-enhanced ultrasound and contrast-enhanced CT

The aim of this study was to compare the enhancement pattern of intrahepatic cholangiocarcinoma (ICC) on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). 40 pathologically proven ICC lesions in 40 patients were evaluated retrospectively with both CEUS and CECT. The enhancement level and pattern in the dynamic phases on both CEUS and CECT were analysed. The diagnostic results of CEUS and CECT before pathological examination were also recorded. During arterial phases, the number of lesions that appeared as (i) peripheral irregular rim-like hyperenhancement, (ii) diffuse heterogeneous hyperenhancement, (iii) diffuse homogeneous hyperenhancement and (iv) diffuse heterogeneous hypoenhancement were 19 (47.5%), 9 (22.5%), 5 (12.5%) and 7 (17.5%), respectively, on CEUS, and 22 (55.0%), 3 (7.5%), 2 (5.0%) and 13 (32.5%), respectively, on CECT (p = 0.125). In the portal phase, the number of lesions showing hyperenhancement and hypoenhancement were 1 (2.5%) and 39 (97.5%), respectively, on CEUS, and 15 (37.5%) and 25 (62.5%) on CECT (p = 0.0001). CEUS made a correct diagnosis in 32 (80.0%) lesions before pathological examination; CECT made a correct diagnosis in 27 (67.5%) lesions (p = 0.18). In conclusion, the enhancement patterns of ICC on CEUS were consistent with those on CECT in the arterial phase, whereas in the portal phase ICC faded out more obviously on CEUS than on CECT. CEUS had the same accuracy as CECT in diagnosing ICCs, and so can be used as a new modality for the characterization of ICC.

Multiple anechoic hepatic nodules in a patient with malignant lymphoma: report of a case with an emphasis on B-mode sonograms

We present a case of hepatic malignant lymphoma (ML) in which the hepatic ML nodules were imaged as round anechoic nodules with posterior echo enhancement, mimicking hepatic cysts on B-mode ultrasonography (US). However, the boundary echo between the nodules and the surrounding hepatic tissue seemed to be less distinct than that of a hepatic cyst. Contrast-enhanced US showed the nodules to be hypervascular, which ruled out the possibility of hepatic cysts. Our observation stresses the importance of boundary echo for the diagnosis of hepatic ML on B-mode US. We also offer a possible explanation for this phenomenon.

Small liver lesions in oncologic patients: characterization with CT, MRI and contrast-enhanced US

Focal liver lesions (FLLs) are frequently discovered during ultrasound examinations either in healthy subjects without a clinical history of cancer or during staging or follow-up procedures in oncologic patients or in routine surveillance of hepatopathic patients. In oncologic patients, the liver is the most common target of metastatic disease and accurate detection and characterisation of FLLs is prognostically fundamental during the initial staging as well as before and after pre-operative chemotherapy, as it can help to identify patients who are most likely to benefit from liver surgery. Moreover, early detection of primary or secondary liver malignancies increases the possibility of curative surgical resection or successful percutaneous ablation. As many FLLs in these patients are benign, a precise and preferably non-invasive method of differentiation from malignant metastatic nodules is needed. Moreover, the continuous follow-up of cancer patients requires an easily available, reliable and cost-effective diagnostic tool for the detection and characterization of FLLs.

Focal liver lesions in cirrhosis: value of contrast-enhanced ultrasonography compared with Doppler ultrasound and alpha-fetoprotein levels

PURPOSE

This study aimed to evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) in characterising focal liver lesions in cirrhosis and to validate its use in lesions discovered during surveillance for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Between 2003 and 2006, 128 cirrhotic patients with focal liver lesions at baseline ultrasonography (US) were studied by power colour Doppler US (Doppler US) and CEUS. Serum alpha-fetoprotein (AFP) levels were assessed in all patients. Fine-needle biopsy or other reference modalities such as computed tomography (CT), magnetic resonance imaging (MRI) or digital subtraction angiography (DSA) were used as the gold standard. The accuracy of baseline US, Doppler US, AFP levels, combined US and AFP levels and combined US, Doppler US and CEUS in characterising focal liver lesions was assessed. Diagnostic performance was compared using the McNemar test.

RESULTS

A total of 207 focal liver lesions (101 benign and 106 malignant) were identified in 128 patients. CEUS sensitivity and specificity for lesion characterisation were 96.2% and 97.0%, respectively, whereas its positive and negative predictive values were 97.1% and 96.1%. CEUS accuracy was 96.6%, higher than that of US (72.0%), Doppler US (70.0%), AFP levels (65.7%), combined US and Doppler US (70.0%) and combined US and AFP levels (90.3%). The differences between US and CEUS were statistically significant (p<0.05).

CONCLUSIONS

CEUS can characterise focal liver lesions with 96.6% accuracy, a value higher than US, Doppler US, AFP levels, combined US and AFP levels and combined US and Doppler US. CEUS should therefore be used to characterise focal liver lesions detected during HCC surveillance of cirrhotic patients.

Value of contrast-enhanced intraoperative ultrasound for cirrhotic patients with hepatocellular carcinoma: a report of 20 cases

AIM

To assess the clinical value of contrast-enhanced intraoperative ultrasound (CE-IOUS) as a novel tool in partial hepatectomy for cirrhotic patients with hepatocellular carcinoma (HCC).

METHODS

From January 2007 to September 2007, a total of 20 consecutive cirrhotic patients with HCC scheduled to undergo partial hepatectomy were studied. Preoperative contrast enhanced computer tomography (CT) and/or magnetic resonance (MR) scans were performed within 1-2 wk before operation. Intraoperative ultrasound (IOUS) and CE-IOUS were carried out after mobilization of the liver. Lesions on precontrast and postcontrast scans were counted and mapped. CE-IOUS was performed with intravenous injection of ultrasound contrast agents SonoVue (Bracco Imaging, Milan, Italy). Arterial, portal and late phases of contrast enhancement were recorded and analyzed. Nodules showing arterial phase hyper-enhancing and/or hypo-enhancing in late parenchymal phase were considered malignant and removed surgically. Ultrasound-guided biopsy and ethanol ablation would be an option if the nodule could not be removed surgically. Newly detected nodules on IOUS showing iso-enhancement in both arterial and late phases were considered benign. These nodules were either removed surgically if they were close to the main lesion or followed by examinations of alpha-fetoprotein (AFP) level and ultrasound and/or CT/MR every 3 mo.

RESULTS

IOUS found 41 nodules in total, among which 17 (41.46%) were newly detected compared to preoperative imaging. Thirty-three nodules were diagnosed malignant by CE-IOUS, including one missed by IOUS. The sensitivity and specificity of CE-IOUS on detecting HCC nodules are 100% (33/33 and 100% (9/9), respectively. Nine nodules were considered benign by CE-IOUS, four was confirmed at histology and five by follow-up. CE-IOUS changed the surgical strategy in 35% (7/20) of patients and avoid unnecessary intervention in 30% (6/20) of patients.

CONCLUSION

CE-IOUS is a useful means to characterize the nodules detected by IOUS in cirrhotic liver, to find isoechoic HCC nodules which can not be shown on IOUS and to improve the accuracy of conventional IOUS, thus it can be used as an essential tool in the surgical treatment of cirrhotic patients with HCC.

Benefits of contrast-enhanced sonography for the detection of liver lesions: comparison with histologic findings

OBJECTIVE

The objective of our study was to compare the usefulness of contrast-enhanced sonography with baseline sonography in detecting malignant liver lesions.

SUBJECTS AND METHODS

This prospective study included 116 patients. All patients underwent a preoperative conventional sonography examination followed by sonography after injection of contrast agent combined with the use of perfusion software (vascular recognition imaging or pulse subtraction imaging). Histopathologic analysis was the reference standard used to compare the diagnostic value of baseline sonography versus contrast-enhanced sonography.

RESULTS

Eighty-two patients underwent hepatic surgery, 31 did not because of disseminated lesions, and the remaining three patients did not meet inclusion criteria. Three hundred six surgically proven lesions were taken into account for comparison of the two techniques: 147 were detected on baseline sonography and 177 on contrast-enhanced sonography. Histopathologic analysis revealed 233 malignant and 73 benign lesions. Sensitivity and specificity were improved on contrast-enhanced sonography compared with baseline sonography for the detection of malignant lesions: 68.7% versus 58.8% and 67% versus 50.7%, respectively. Contrast-enhanced sonography detected 23 additional malignant lesions that had been seen as lacuna at the portal venous phase and characterized as 19 benign nodules, thus improving the performance of sonography in 13.7% of the cases.

CONCLUSION

Contrast injection improved the sensitivity and specificity of baseline sonography and should be performed in routine practice if hepatic surgery is being considered for the management of liver lesions.

Standardize and compare contrast-enhanced ultrasonographic digital images obtained with different technologies: how to overcome the subjectivity

OBJECTIVE

This study was conducted to compare digital images obtained with cadence contrast pulse sequencing (CPS) and coherent contrast imaging (CCI) technologies for contrast-enhanced ultrasonography (CEUS).

METHODS

A CEUS study on 17 focal liver lesions was performed using CPS and CCI technologies with a second-generation contrast media. The lesion/liver ratio and conspicuity index were then calculated and compared with Adobe Photoshop 6.0.

RESULTS

Lesion/liver ratio and conspicuity index using CCI ranged from 1.3 to 7.1 (mean value, 3) and 19 to 127 (mean value, 58), respectively; by using CPS, we obtained results ranging from 2 to 19.1 (mean value, 8.9) and 57 to 164 (mean value, 109.2). Lesion/liver ratio and the conspicuity index for the lesions using CPS showed significantly (p < 0.0001) superior results than those obtained using CCI.

CONCLUSION

The computed analysis with standardization allows an objective evaluation of digital images of CEUS. CPS technology resulted in better lesion conspicuity compared to CCI during CEUS study on focal liver lesions.

Evaluation of quantitative contrast harmonic imaging to assess malignancy of liver tumors: A prospective controlled two-center study

AIM: To establish the extent to which contrast enhancement with SonoVue in combination with quantitative evaluation of contrast-medium dynamics facilitates the detection of hepatic tumors.

METHODS: One hundred patients with histologically confirmed malignant or benign hepatic tumor (maximum size 5 cm) were analyzed. Contrast-enhanced ultrasound (bolus injection 2.5 mL SonoVue) was carried out with intermittent breath-holding technique using a multifrequency transducer (2.5-4 MHz). Native vascularization was analyzed with power Doppler. The contrast-enhanced dynamic ultrasound investigation was carried out with contrast harmonic imaging in true detection mode during the arterial, portal venous and late phases. Mechanical index was set at 0.15. Perfusion analysis was performed by post-processing of the raw data [time intensity curve (TIC) analysis]. The cut-off of the gray value differences between tumor and normal liver tissue was established using Receiver Operating Characteristic (ROC) analysis 64-line multi-slice computed tomography served as reference method in all cases. Magnetic resonance tomography was used additionally in 19 cases.

RESULTS: One hundred patients with 59 malignant (43 colon, 5 breast, 2 endocrine metastases, 7 hepatocellular carcinomas and 2 kidney cancers) and 41 benign (15 hemangiomas, 7 focal nodular hyperplasias, 5 complicated cysts, 2 abscesses and 12 circumscribed fatty changes) tumors were included. The late venous phase proved to be the most sensitive for classification of the tumor type. Fifty-eight of the 59 malignant tumors were classified as true positive, and one as false negative. This resulted in a sensitivity of 98.3%. Of the 41 benign tumors, 37 were classified as true negative and 4 as false negative, which corresponds to a specificity of 90.2%. Altogether, 95.0% of the diagnoses were classified as correct on the basis of the histological classification. No investigator-dependency (P = 0.23) was noted.

CONCLUSION: The results show the possibility of accurate prediction of malignancy of hepatic tumors with a positive prognostic value of 93.5% using advanced contrast-enhanced ultrasound. Contrast enhancement with SonoVue in combination with quantitative evaluation of contrast-medium dynamics is a valuable tool to discriminate hepatic tumors.

Ultrasonography of the pancreas. 4. Contrast-enhanced imaging

The introduction of contrast-enhanced ultrasonography (CEUS) has lead to great developments in the diagnostic capabilities of ultrasound. Second generation contrast media, characterized by harmonic responses at low mechanical index of the ultrasound beam, have already proven usefulness in the study of the liver but other abdominal organs can take advantage from the dynamic study during continuous ultrasonographic scans. The dynamic observation of the enhancement allows the perfect evaluation of the abdominal organs perfusion. The perfusion of the pancreas is well correlated to the semeiology of the gland parenchymography at CEUS. The study of the pancreas is a new and promising application of CEUS. CEUS can be used to better identify pancreatic lesions respect to conventional Ultrasound (US) or to characterize pancreatic lesions already visible at US. Moreover the staging of some pancreatic lesions can be improved by the use of contrast media. This article will review the clinical application of CEUS in the different pancreatic pathologies.

Contrast-enhanced ultrasonography in the characterization of benign focal liver lesions: activity-based cost analysis

PURPOSE

The aim of this study was to perform a cost analysis of contrast-enhanced ultrasonography (CEUS) in the study of benign focal liver lesions (BFLL) with indeterminate appearance on ultrasonography (US).

MATERIALS AND METHODS

A decision model of patients with suspected BFLL on baseline US who subsequently underwent CEUS between 2002 and 2005 was constructed. We analysed the cost effectiveness of CEUS, considering whether or not computed tomography (CT) was necessary for the diagnosis. There were 398 patients with 213 angiomas, 41 focal nodular hyperplasias (FNH) and 154 pseudolesions (focal fatty sparing, focal fatty areas). Each patient underwent CEUS, and 98 of them were also studied by CT. All lesions were followed up.

RESULTS

The cost of a single CEUS examination was 101.51 euros, and that of a single CT scan was 211.48 euros. For diagnosis of haemangiomas, we saved 1,406.97 euros in 2002, 5,315.22 euros in 2003, 10,317.78 euros in 2004 and 9,536.13 euros in 2005. For diagnosis of focal nodular hyperplasias, we saved 781.65 euros in 2003, 781.65 euros in 2004 and 1,406.97 euros in 2005. For diagnosis of pseudolesions, we saved 2,813.94 euros in 2002, 5,158.89 euros in 2003, 5,158.89 euros in 2004 and 4,220.91 euros in 2005. In the period 2002-2005, the introduction of CEUS allowed us to save a total of 47,055.33 euros in the diagnosis of benign focal hepatic liver lesions.

CONCLUSIONS

This cost analysis shows that CEUS is the least expensive second-line modality after baseline US for the diagnosis of BFLL.

Focal nodular hyperplasia: Spoke-wheel arterial pattern and other signs on dynamic contrast-enhanced ultrasonography

OBJECTIVE

To evaluate the prevalence of spoke-wheel pattern and typical symptoms of focal nodular hyperplasia (FNH) by means of dynamic contrast-enhanced ultrasonography (CEUS) in relation to lesion size.

METHODS

Twenty-eight patients were included in the trial, in whom, based on the CEUS, we raised suspicion of hypervascularized liver lesion; there were 30 lesions altogether. The final diagnosis of FNH was verified by means of CT, MRI or lesion biopsy. Majority of patients (26) were females, compared to 2 male, with average age of 33.3 years. Average lesion size was 45.6 mm. Besides the ultrasound examination, we used also "blood pool" ultrasound contrast agent of second generation, sulphur hexafluoride (BR1); we evaluated enhancement of the lesion until the late stage-within 5 min from application.

RESULTS

In lesions larger than 3 cm (n=20), stellate vascular enhancement was found in 19 cases (95.0%) early in arterial phase. As for lesions smaller than 3 cm (n=10), spoke-wheel pattern was observed only in 3 cases (30%) and lesions smaller than 2 cm practically did not show this phenomenon at all (n=1; 17%). Generally, symptom of spoke-wheel pattern was observed in 22 cases, i.e. in 73.3%. In total, central scar was present in 63.3% (n=19) of cases. In lesions larger than 3 cm, it was present in 85.0% (n=17), in lesions smaller than 3 cm in 20% (n=2).

CONCLUSION

Contrast-enhanced ultrasonography can be the final diagnostic method for FNH larger than 3 cm which has typical spoke-wheel vessel structure on CEUS. If this phenomenon is not present and the central scar is not visible, specific diagnosis of FNH cannot be based solely on CEUS findings.