Carcinoembryonic antigen in the diagnosis,treatment,and follow-up of focal liver lesions

In this editorial review,we comment on the article published in the recent issue of the World Journal of Gastrointestinal Surgery.Carcinoembryonic antigen(CEA)is a fetal glycoprotein and can be secreted in very small amounts from healthy adults after birth.CEA is widely used not only for diagnostic tumor markers but also importantly for the management of some gastrointestinal tumors.The most common clinical use is surveillance for the monitoring of colorectal carcinoma.However,CEA can become elevated in several malign or benign characterized pathologies.Serum CEA level may vary depending on the location of the lesion,whether it metastasizes or not,and its histopathological characteristics.It has been determined that cases with high preoperative CEA have a more aggressive course and the risk of metastasis to the lymph tissue and liver increases.In this editorial review,we focused on evaluating the role of CEA in clinical practice with a holistic approach,including the diagnostic and prognostic significance of CEA in patients with focal liver lesions,the role of CEA in follow-up after definitive surgery,and also hepatic resection for metastasis,and the management of all patients with raised CEA.

Imaging features and management of focal liver lesions

Notably,the number of incidentally detected focal liver lesions(FLLs)has increa-sed dramatically in recent years due to the increased use of radiological imaging.The diagnosis of FLLs can be made through a well-documented medical history,physical examination,laboratory tests,and appropriate imaging methods.Although benign FLLs are more common than malignant ones in adults,even in patients with primary malignancy,accurate diagnosis of incidental FLLs is of utmost clinical significance.In clinical practice,FLLs are frequently evaluated non-invasively using ultrasound(US),computed tomography(CT),and magnetic resonance imaging(MRI).Although US is a cost-effective and widely used imaging method,its diagnostic specificity and sensitivity for FLL characterization are limited.FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI.MRI is a problem-solving method with high specificity and sensitivity,commonly used for the evaluation of FLLs that cannot be characterized by US or CT.Recent technical advancements in MRI,along with the use of hepatobiliary-specific MRI contrast agents,have significantly improved the success of FLL characterization and reduced unnece-ssary biopsies.The American College of Radiology(ACR)appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients.ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommend-ations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios.The American College of Gastroenterology(ACG)Clinical Guideline offers evidence-based recommend-ations for both the diagnosis and management of FLL.American Association for the Study of Liver Diseases(AASLD)Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma.In this article,FLLs are reviewed with a comprehensive analysis of ACR Appropri-ateness Criteria,ACG Clinical Guideline,AASLD Practice Guidance,and current medical literature from peer-reviewed journals.The article includes a discussion of imaging methods used for the assessment of FLL,current recommended imaging techniques,innovations in liver imaging,contrast agents,imaging features of common nonmetastatic benign and malignant FLL,as well as current management recommendations.

Gd-EOB-DTPA-enhanced magnetic resonance imaging for focal liver lesions in Chinese patients:a multicenter,open-label,phase Ⅲ study

BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions and healthy tissue.This study was undertaken to evaluate the efficacy and safety of the liverspecific MR imaging contrast agent gadoxetate disodium(GdEOB-DTPA)in Chinese patients.METHODS:This was a single-arm,open-label,multicenter study in patients with known or suspected focal liver lesions referred for contrast-enhanced MR imaging.MR imaging was performed in 234 patients before and after a single intravenous bolus of Gd-EOB-DTPA(0.025 mmol/kg body weight).Images were evaluated by clinical study investigators and three independent,blinded radiologists.The primary efficacy endpoint was sensitivity in lesion detection.RESULTS:Gd-EOB-DTPA improved sensitivity in lesion detection by 9.46%compared with pre-contrast imaging for the average of the three blinded readers(94.78%vs 85.32%for Gd-EOB-DTPA vs pre-contrast,respectively).Improvements in detection were more pronounced in lesions less than 1cm.Gd-EOB-DTPA improved diagnostic accuracy in lesion classification.CONCLUSIONS:This open-label study demonstrated that Gd-EOB-DTPA improves diagnostic sensitivity in liver lesions,particularly in those smaller than 1 cm.Gd-EOB-DTPA also significantly improves the diagnostic accuracy in lesion classification,and furthermore,Gd-EOB-DTPA is safe in Chinese patients with liver lesions.

Application of superb microvascular imaging in focal liver lesions

AIM To explore the ability of superb microvascular imaging(SMI) in differential diagnosis of focal liver lesions(FLLs) and to compare SMI morphology findings to those of color Doppler ultrasound and enhanced imaging.METHODS Twenty-four patients with 31 FLLs were included in our study,with diagnoses of hemangioma(HE)(n = 17),hepatocellular carcinoma(HCC)(n = 5),metastatic lesions(n = 5),primary hepatic lymphoma(n = 1),focal nodular hyperplasia(FNH)(n = 2),and adenoma(n = 1). Nine lesions were pathologically diagnosed,and 22 lesions were radiologically confirmed,all of which were evaluated by at least two types of enhanced imaging techniques. All patients had undergone SMI. Patients were divided into subgroups based on pathological and radiological diagnoses to analyze SMI manifestations. We also compared the SMI manifestations of the most common malignant FLLs(HCCs and metastatic lesions) with those of the most common benign FLLs(HEs).RESULTS HEs were classified into three SMI subgroups: diffuse dot-like type(n = 6),strip rim type(n = 8),and nodular rim type(n = 3). The sizes of the three types of HEs were significantly different(P = 0.00,< 0.05). HCCs were classified into two subgroups: diffuse honeycomb type(n = 2) and non-specific type(n = 3). Four of the metastatic lesions were the strip rim type,and the other metastatic lesion was the thick rim type,which is the same as that of lymphoma. FNH was described as a spoke-wheel type,and adenoma as a diffuse honeycomb type. The SMI types of HCCs and metastatic lesions were significantly different from those of HEs(P = 0.048,< 0.05).CONCLUSION SMI technology enables microvascular evaluation of FLLs without using any contrast agent. For HEs,lesion size may affect SMI performance. SMI is able to provide useful information for differential diagnosis of HCCs and metastatic lesions from HEs.

Use of second generation contrast-enhanced ultrasound in the assessment of focal liver lesions

Ultrasound (US) is often the first imaging modality employed in patients with suspected focal liver lesions. The role of US in the characterisation of focal liver lesions has been transformed with the introduction of specific contrast media and the development of specialized imaging techniques. Ultrasound now can fully characterise the enhancement pattern of hepatic lesions, similar to that achieved with contrast enhanced multiphasic computed tomography (CT) and magnetic resonance imaging (MRI). US contrast agents are safe, well-tolerated and have very few contraindications. Furthermore, real-time evaluation of the vascularity of focal liver lesions has become possible with the use of the newer microbubble contrast agents. This article reviews the enhancement pattern of the most frequent liver lesions seen, using the second generation US contrast media. The common pitfalls for each type of lesion are discussed. The recent developments in US contrast media and specific imaging techniques have been a major advance and this technique, in view of the intrinsic advantages of US, will undoubtedly gain popularity in the years to come.

Combination of acoustic radiation force impulse imaging, serological indexes and contrast-enhanced ultrasound for diagnosis of liver lesions

AIM To assess the value of combined acoustic radiation force impulse(ARFI) imaging, serological indexes and contrast-enhanced ultrasound(CEUS) in distinguishing between benign and malignant liver lesions. METHODS Patients with liver lesions treated at our hospital were included in this study. The lesions were divided into either a malignant tumor group or a benign tumor group according to pathological or radiological findings. ARFI quantitative detection, serological testing and CEUS quantitative detection were performed and compared. A comparative analysis of the measured indexes was performed between these groups. Receiver operating characteristic(ROC) curves were constructed to compare the diagnostic accuracy of ARFI imaging, serological indexes and CEUS, alone or in different combinations, in identifying benign and malignant liver lesions. RESULTS A total of 112 liver lesions in 43 patients were included, of which 78 were malignant and 34 were benign. Shear wave velocity(SWV) value, serum alpha-fetoprotein(AFP) content and enhancement rate were significantly higher in the malignant tumor group than in the benign tumor group(2.39 ± 1.20 m/s vs 1.50 ± 0.49 m/s, 18.02 ± 5.01 ng/m L vs 15.96 ± 4.33 ng/m L, 2.14 ± 0.21 d B/s vs 2.01 ± 0.31 d B/s; P < 0.05). The ROC curve analysis revealed that the areas under the curves(AUCs) of SWV value alone, AFP content alone, enhancement rate alone, SWV value + AFP content, SWV value + enhancement rate, AFP content + enhancement rate and SWV value + AFP content + enhancement rate were 85.1%, 72.1%, 74.5%, 88.3%, 90.4%, 82.0% and 92.3%, respectively. The AUC of SWV value + AFP content + enhancement rate was higher than those of SWV value + AFP content and SWV value + enhancement rate, and significantly higher than those of any single parameter or the combination of any two of parameters.CONCLUSION The combination of SWV, AFP and enhancement rate had better diagnostic performance in distinguishing between benign and malignant liver lesions than the use of any single parameter or the combination of any two of parameters. It is expected that this would provide a tool for the differential diagnosis of benign and malignant liver lesions.

Ultrasound elastographic techniques in focal liver lesions

Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses.

Clinical value of contrast-enhanced ultrasonography in the characterization of focal liver lesions:a prospective multicenter trial

BACKGROUND: Contrast-enhanced ultrasonography (CEUS) is increasingly accepted in clinical settings for diagnostic imaging of focal liver lesions (FLLs). This study aimed to assess the efficacy of CEUS in the characterization of FLLs in comparison with final diagnosis based on gold standard assessment. METHODS: The study was approved by the local ethics committee and participating patients provided written informed consent. A total of 148 patients with 164 FLLs were studied. Unenhanced ultrasonography (US) and CEUS were performed using fundamental and harmonic imaging, respectively. Contrast enhancement was assessed during the arterial, portal and late vascular phases after intravenous administration of contrast (SonoVue (R), Bracco, Italy). Sensitivity, specificity and diagnostic accuracy of US and CEUS were compared in identifying the lesion as benign, malignant or indeterminate and its actual tumor type. Final diagnosis was established by biopsy (129/164), MR imaging (11/164) or medical history (24/164). RESULTS: When compared to the gold standard, the number of indeterminate diagnoses was reduced from 56.7% (93/164) as assessed by fundamental imaging to 6.1% (10/164) after SonoVue (R) enhanced US examination. Sensitivity and specificity improved from 49% and 25% at baseline US to 93% and 75% with CEUS, respectively (P<0.01). Diagnostic accuracy of CEUS was 88% in contrast to 41% of baseline US. CONCLUSION: SonoVue (R) enhanced US improves the characterization of FLLs and may limit the need for further investigations.

Differential diagnosis of different types of solid focal liver lesions using two-dimensional shear wave elastography

BACKGROUND The clinical management and prognosis differ between benign and malignant solid focal liver lesions(FLLs),as well as among different pathological types of malignant FLLs.Accurate diagnosis of the possible types of solid FLLs is important.Our previous study confirmed the value of shear wave elastography(SWE)using maximal elasticity(Emax)as the parameter in the differential diagnosis between benign and malignant FLLs.However,the value of SWE in the differential diagnosis among different pathological types of malignant FLLs has not been proved.AIM To explore the value of two-dimensional SWE(2D-SWE)using Emax in the differential diagnosis of FLLs,especially among different pathological types of malignant FLLs.METHODS All the patients enrolled in this study were diagnosed as benign,malignant or undetermined FLLs by conventional ultrasound.Emax of FLLs and the periphery of FLLs was measured using 2D-SWE and compared between benign and malignant FLLs or among different pathological types of malignant FLLs.RESULTS The study included 32 benign FLLs in 31 patients and 100 malignant FLLs in 96 patients,including 16 cholangiocellular carcinomas(CCCs),72 hepatocellular carcinomas(HCCs)and 12 liver metastases.Thirty-five FLLs were diagnosed as undetermined by conventional ultrasound.There were significant differences between Emax of malignant(2.21±0.57 m/s)and benign(1.59±0.37 m/s)FLLs(P=0.000),and between Emax of the periphery of malignant(1.52±0.39 m/s)and benign(1.36±0.44 m/s)FLLs(P=0.040).Emax of liver metastases(2.73±0.99 m/s)was significantly higher than that of CCCs(2.14±0.34 m/s)and HCCs(2.14±0.46 m/s)(P=0.002).The sensitivity,specificity and accuracy were 71.00%,84.38%and 74.24%respectively,using Emax>1.905 m/s(AUC 0.843)to diagnose as malignant and 23 of 35(65.74%)FLLs with undetermined diagnosis by conventional ultrasound were diagnosed correctly.CONCLUSION Malignant FLLs were stiffer than benign ones and liver metastases were stiffer than primary liver carcinomas.2D-SWE with Emax was a useful complement to conventional ultrasound for the differential diagnosis of FLLs.

Multiphase convolutional dense network for the classification of focal liver lesions on dynamic contrast-enhanced computed tomography

BACKGROUND The accurate classification of focal liver lesions(FLLs)is essential to properly guide treatment options and predict prognosis.Dynamic contrast-enhanced computed tomography(DCE-CT)is still the cornerstone in the exact classification of FLLs due to its noninvasive nature,high scanning speed,and high-density resolution.Since their recent development,convolutional neural network-based deep learning techniques has been recognized to have high potential for image recognition tasks.AIM To develop and evaluate an automated multiphase convolutional dense network(MP-CDN)to classify FLLs on multiphase CT.METHODS A total of 517 FLLs scanned on a 320-detector CT scanner using a four-phase DCECT imaging protocol(including precontrast phase,arterial phase,portal venous phase,and delayed phase)from 2012 to 2017 were retrospectively enrolled.FLLs were classified into four categories:Category A,hepatocellular carcinoma(HCC);category B,liver metastases;category C,benign non-inflammatory FLLs including hemangiomas,focal nodular hyperplasias and adenomas;and category D,hepatic abscesses.Each category was split into a training set and test set in an approximate 8:2 ratio.An MP-CDN classifier with a sequential input of the fourphase CT images was developed to automatically classify FLLs.The classification performance of the model was evaluated on the test set;the accuracy and specificity were calculated from the confusion matrix,and the area under the receiver operating characteristic curve(AUC)was calculated from the SoftMax probability outputted from the last layer of the MP-CDN.RESULTS A total of 410 FLLs were used for training and 107 FLLs were used for testing.The mean classification accuracy of the test set was 81.3%(87/107).The accuracy/specificity of distinguishing each category from the others were 0.916/0.964,0.925/0.905,0.860/0.918,and 0.925/0.963 for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.The AUC(95%confidence interval)for differentiating each category from the others was 0.92(0.837-0.992),0.99(0.967-1.00),0.88(0.795-0.955)and 0.96(0.914-0.996)for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.CONCLUSION MP-CDN accurately classified FLLs detected on four-phase CT as HCC,metastases,benign non-inflammatory FLLs and hepatic abscesses and may assist radiologists in identifying the different types of FLLs.

Indeterminate liver lesions on gadoxetic acid-enhanced magnetic resonance imaging of the liver:Case-based radiologic-pathologic review

Different histopathological manifestations of focal liver lesions show varying common and uncommon imaging findings and some pathologies may show similar appearance despite of different histopathology.It is necessary to characterise focal liver lesions accurately as not only benign and malignant lesions are managed differently,but also certain benign lesions have differing management.These lesions are increasingly being detected due to rapid growth of use of crosssectional imaging as well as improvement in image quality and new imaging techniques.Contrast enhanced magnetic resonance imaging(MRI)is considered the gold standard technique in characterising focal liver lesions.Addition of gadoxetic acid has been shown to significantly increase diagnostic accuracy in the detection and characterization of liver abnormalities.Classic imaging characteristics of common liver lesions,including their behaviour on gadoxetic acid enhanced MRI,have been described in literature over recent years.It is important to be familiar with the typical aspects of these lesions as well as know the uncommon and overlapping imaging features to reach an accurate diagnosis.In this article,we will review the well-described characteristic imaging findings of common and rare focal liver lesions and present several challenging cases encountered in the clinical setting,namely hepatocellular adenoma,focal nodular hyperplasia,hepatic angiomyolipoma,hepatocellular carcinoma,intrahepatic cholangiocarcinoma,neuroendocrine tumours as well as a pleomorphic liposarcoma of the liver.

MR-arterioportography: A new technical approach for detection of liver lesions

AIM: To evaluate the benefit and effectiveness of MRarterioportography (MR-AP) to achieve the highest sensitivity for detection and evaluation of hepatocellular carcinoma (HCC). METHODS: Twenty liver cirrhosis patients with suspected HCC were included before transarterial chemoembolization. In all patients double-enhanced Magnetic resonance imaging (MRI) was performed. A bolus of 10 mL Magnevist was injected through a selectively placed catheter in the superior mesenteric artery and MRI of the liver was performed in arterioportographic phase. Two independent readers evaluated number, size and localization of detected lesions. Diagnostic quality was determined using a 4-point scale. Differences were analyzed for significance using a t -test. Interobserver variability was calculated. RESULTS: In all 20 patients (100%), MR-AP was feasible. Diagnostic quality was, in all cases, between 1 and2 for both modalities and readers. MR-AP detected significantly more lesions than double-enhanced MRI (102.5 vs 61, respectively, P < 0.0024). The inter-observer variability was 0.881 for MRI and 0.903 for MR-AP. CONCLUSION: Our study confirmed that the MR-AP as an additional modality for detection of HCC is beneficial, as significantly more lesions were detected compared to MRI with liver-specific contrast.

Differentiating malignant and benign focal liver lesions in children using CEUS LI-RADS combined with serum alpha-fetoprotein

BACKGROUND Contrast-enhanced ultrasound(CEUS)can be used to diagnose focal liver lesions(FLLs)in children.The America College of Radiology developed the CEUS liver imaging reporting and data system(LI-RADS)for standardizing CEUS diagnosis of FLLs in adult patients.Until now,no similar consensus or guidelines have existed for pediatric patients to improve imaging interpretation as adults.AIM To evaluate the performance of CEUS LI-RADS combined with alpha-fetoprotein(AFP)in differentiating benign and malignant FLLs in pediatric patients.METHODS Between January 2011 and January 2021,patients≤18 years old who underwent CEUS for FLLs were retrospectively evaluated.The following criteria for diagnosing malignancy were proposed:Criterion I considered LR-4,LR-5,or LRM lesions as malignancies;criterion II regarded LR-4,LR-5 or LR-M lesions with simultaneously elevated AFP(≥20 ng/mL)as malignancies;criterion III took LR-4 Lesions with elevated AFP or LR-5 or LR-M lesions as malignancies.The sensitivity,specificity,accuracy and area under the receiver operating characteristic curve(AUC)were calculated to determine the diagnostic value of the aforementioned criteria.RESULTS The study included 63 nodules in 60 patients(mean age,11.0±5.2 years;26 male).There were no statistically significant differences between the specificity,accuracy,or AUC of criterion II and criterion III(95.1%vs 80.5%,84.1%vs 87.3%,and 0.794 vs 0.902;all P>0.017).Notably,criterion III showed a higher diagnostic sensitivity than criterion II(100%vs 63.6%;P<0.017).However,both the specificity and accuracy of criterion I was inferior to those of criterion II and criterion III(all P<0.017).For pediatric patients more than 5 years old,the performance of the three criteria was overall similar when patients were subcategorized by age when compared to all patients in aggregate.CONCLUSION CEUS LI-RADS combined with AFP may be a powerful diagnostic tool in pediatric patients.LR-4 with elevated AFP,LR-5 or LR-M lesions is highly suggestive of malignant tumors.

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 realtime 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.

Focal liver lesions found incidentally

Incidentally found focal liver lesions are a commonfinding and a reason for referral to hepatobiliary service.They are often discovered in patients with history of liver cirrhosis,colorectal cancer,incidentally during work up for abdominal pain or in a trauma setting.Specific points should considered during history taking such as risk factors of liver cirrhosis;hepatitis,alcohol consumption,substance exposure or use of oral con-traceptive pills and metabolic syndromes.Full blood count,liver function test and tumor markers can act as a guide to minimize the differential diagnosis and to categorize the degree of liver disease.Imaging should start with B-mode ultrasound.If available,contrast enhanced ultrasound is a feasible,safe,cost effective option and increases the ability to reach a diagnosis.Contrast enhanced computed tomography should be considered next.It is more accurate in diagnosis and better to study anatomy for possible operation.Contrast enhanced magnetic resonance is the gold standard with the highest sensitivity.If doubt still remains,the options are biopsy or surgical excision.

Value of contrast-enhanced ultrasound in diagnosis of focal liver lesions

Objective： By observing the pattern of the focal liver lesions （FLL） in different phases by real time contrast-enhanced ultrasound （CEUS）, compared to enhanced CT, investigate the value of CEUS in diagnosing focal liver lesions. Meth. ods： 35 patients with unconfirmed focal liver lesions were studied by contrast agent SonoVue and Technos DU 8 produced by Esaote company. Results： Among the 14 cases of hepatocellular carcinoma （HCC）, 10 were typical, presented with early artery enhancement and immediate wash-out. The enhancement patterns of 6 livers metastasis were diverse, including peripheral or entire degree enhancement. The wash-out time in malignant tumors was eadier than other focal liver lesions （P 〈 0.05）, appeared as hypoechoic in the portal phase or parenchyma phase. The 6 cases of hemangioma were enhanced centripetally nodular in artery phase and washed out after several minutes. The patterns of different lesions were similar compared to contrast-enhanced CT, without significant statistic differences. Conclusion： The contrast enhanced ultrasound technique can significantly improved the value of diagnosing focal liver lesions.

Characterization of focal liver lesions with SonoVue~-enhanced sonography: International multicenter-study in comparison to CT and MRI

AIM： To evaluate in a multicenter study whether the sonographic characterization of focal liver lesions can be improved using SonoVue-enhancement; and to compare this method with computed tomography （CT） and magnetic resonance imaging （MRI）. METHODS： One hundred and thirty four patients withone focal liver lesion detected in baseline ultrasound （US） were examined with conventional US, contrastenhanced US （n = 134）, contrast-enhanced CT （n = 115） and/or dynamic contrast-enhanced MRI （n = 70）. The lesions were classified as malignant, benign or indeterminate and the type of lesion was determined. The final diagnosis based on the combined information of all imaging examinations, clinical information and histology （n = 32） was used. Comparisons were made to see whether the addition of contrast-enhanced US led to the improvement of the characterization of doubtful focal liver lesions.RESULTS： In comparison with unenhanced US, SonoVue markedly improves sensitivity and specificity for the characterization （malignant/benign） of focal liver lesions. In comparison with CT and/or dynamic MRI, SonoVue -enhanced sonography applied for characterization of focal liver lesions was 30.2% more sensitive in the recognition of malignancy and 16.1% more specific in the exclusion of malignancy and overall 22.9% more accurate. In the subgroup with confirmative histology available （n = 30）, sensitivity was 95.5% （CEUS）, 72.2% （CT） and 81.8% （MRI）, and specificity was 75.0% （CEUS）, 37.5% （CT） and 42.9% （MRI）. The sensitivity and specificity of CEUS for the identification of focal nodular hyperplasia （FNH） and hemangiomas was 100% and 87%, resulting in an accuracy of 94.5%.CONCLUSION： SonoVue-enhanced sonography emerges as the most sensitive, ost specific and thus most accurate imaging modality for the characterization of focal liver lesions.

R2^(*) value derived from multi-echo Dixon technique can aid discrimination between benign and malignant focal liver lesions

BACKGROUND R2^(*)estimation reflects the paramagnetism of the tumor tissue,which may be used to differentiate between benign and malignant liver lesions when contrast agents are contraindicated.AIM To investigate whether R2^(*)derived from multi-echo Dixon imaging can aid differentiating benign from malignant focal liver lesions(FLLs)and the impact of 2D region of interest(2D-ROI)and volume of interest(VOI)on the outcomes.METHODS We retrospectively enrolled 73 patients with 108 benign or malignant FLLs.All patients underwent conventional abdominal magnetic resonance imaging and multi-echo Dixon imaging.Two radiologists independently measured the mean R2^(*)values of lesions using 2D-ROI and VOI approaches.The Bland-Altman plot was used to determine the interobserver agreement between R2^(*)measurements.Intraclass correlation coefficient(ICC)was used to determine the reliability between the two readers.Mean R2^(*)values were compared between benign and malignant FFLs using the nonparametric Mann-Whitney test.Receiver operating characteristic curve analysis was used to determine the diagnostic performance of R2^(*)in differentiation between benign and malignant FFLs.We compared the diagnostic performance of R2^(*)measured by 2D-ROI and VOI approaches.RESULTS This study included 30 benign and 78 malignant FLLs.The interobserver reproducibility of R2^(*)measurements was excellent for the 2D-ROI(ICC=0.994)and VOI(ICC=0.998)methods.Bland-Altman analysis also demonstrated excellent agreement.Mean R2^(*)was significantly higher for malignant than benign FFLs as measured by 2D-ROI(P<0.001)and VOI(P<0.001).The area under the curve(AUC)of R2^(*)measured by 2D-ROI was 0.884 at a cut-off of 25.2/s,with a sensitivity of 84.6%and specificity of 80.0%for differentiating benign from malignant FFLs.R2^(*)measured by VOI yielded an AUC of 0.875 at a cut-off of 26.7/s in distinguishing benign from malignant FFLs,with a sensitivity of 85.9%and specificity of 76.7%.The AUCs of R2^(*)were not significantly different between the 2D-ROI and VOI methods.CONCLUSION R2^(*)derived from multi-echo Dixon imaging whether by 2D-ROI or VOI can aid in differentiation between benign and malignant FLLs.

Clinical Value of Contrast-enhanced Ultrasound in Differentiating Benign and Malignant Focal Liver Lesions

To explore the clinical value of contrast-enhanced ultrasound （CEUS） in differentiating benign and malignant focal liver lesions （FLLs） with SonoVue, CEUS was used to examine 113 patients with focal liver lesions （FLLs） in our hospital during July 2005 to December 2006. All the patients underwent contrast-enhanced CT （CECT） or contrast-enhanced MRI （CEMRI）. Except for patients with focal fatty sparings （n=18） and with hemangiomas （n=8）, all the patients were confirmed by operation or ultrasonic-guided liver puncture biopsy. A sulfur hexafluoride gas-based contrast agent was used with a MI of 0.15 to 0.17. Forty-eight cases of malignant FLLs, including 30 hepatocellular carcinomas （HCCs）, 2 cholangiocarcinomas and 16 metastatic tumors, were detected. Seventy-eight cases of benign FLLs, including 33 hemangiomas, 9 focal nodular hyperplasias （FNHs）, 19 focal fatty sparings, 5 abscesses, 7 regenerative nodules and 2 inflammatory pseudo-tumor, were involved. The contrast pattern of benign and malignant FLLs was quite different. CEUS has higher specificity and sensitivity than conventional ultrasound in differentiating benign and malignant FLLs.

Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors,the histopathology examination can assist in diagnosis,staging,prognosis,and therapeutic management strategy.Endoscopic ultrasound(EUS)-guided tissue acquisition using fine needle aspiration(FNA)or more newly fine needle biopsy(FNB)is a well-developed technique in order to evaluate and differentiate the liver masses.The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination.Therefore,malignant tumors such as hepatocarcinoma,cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma,focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition.EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA.Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously,ultrasound,computer tomography or transjugulary-guided liver biopsies.This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples.The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented.The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis,especially for those who require endoscopy.