Role of endoscopic ultrasound and endoscopic ultrasound-guided tissue acquisition in diagnosing hepatic focal lesions

BACKGROUND Endoscopic ultrasonography(EUS)has become an established method in diagnostic and therapeutic procedures in gastroenterology;however,it has recently gained a growing role in hepatology.AIM To evaluate the role of EUS features,strain elastography(SE),and EUS-tissue acquisition in diagnosing hepatic focal lesions(HFLs)that could affect further management.METHODS This cross-sectional study included 215 patients with pancreatic,biliary,or gastrointestinal malignancies referred for EUS examination.HFLs were identified in 43 patients(20%),and EUSguided tissue acquisition was performed from these lesions.RESULTS EUS features were highly sensitive(100%)but much less specific(57%)in diagnosing HFLs;the overall accuracy was 94%.Real-time elastography was also very sensitive(97%)but less specific(67%)in diagnosing HFLs;however,the overall accuracy was 92%.EUS tissue acquisition was extremely sensitive(100%)and specific(100%),with a 100%overall diagnostic accuracy.CONCLUSION The diagnostic utility of EUS-guided tissue acquisition was extremely accurate in diagnosing HFLs.EUS characteristics and real-time SE accurately predicted the histological diagnosis of both benign and malignant HFLs.

Diagnosis and excision of breast multi-focal lesions by ultrasound-guided vacuum-assisted biopsy:a comparative evaluation

Objective To compare and evaluate the efficacy of diagnosis and excision for appropriately selected breast multi-focal lesions and solitary lesion by ultrasound-guided vacuum-assisted biopsy(UGVAB).Methods Among 392 appropriately selected patients,187 patients with multi-focal lesions and 205 patients with solitary lesion were treated by the 8-gauge UGVAB from May 2007 to June 2009.All lesions were removed as completely as possible.The patients with benign pathology underwent physical and ultrasound examinations at one week and 6 months after procedure.Results During the procedure,only three patients had vasovagal syncope and twenty others complained of other intraoperative discomfort.An accurate pathological diagnosis was obtained in all lesions.There was no apparent false-negative result among the 696 lesions with benign pathology at a follow-up of 6 months after procedure.The rates of malignant or premalignant pathology,postoperative complications and residual lesions in patients with multi-focal lesions were higher than those in patients with solitary lesion.If each lesion was considered as a subject of study,there was no significant difference between the two groups.Conclusion UGVAB is an effective method for diagnosis and excision of appropriately selected breast multi-focal lesions and can be used routinely.

Diffusion-Weighted MR Imaging of the Benign Hepatic Focal Lesions

Purpose: To determine the role of diffusion weighted MR imaging and apparent diffusion coefficient (ADC) in benign hepatic focal lesions. Method and Materials: This study included 47 patients (29 M, 18 F with mean age of 43 years) with benign hepatic focal lesions. They were cyst (n = 8), hemangioma (n = 23), abscess (n = 5), adenoma (n = 5), focal nodular hyperplasia (n = 4) and nodular regenerative hyperplasia (n = 2). They underwent routine MR imaging and diffusion MR weighted imaging using 1.5 tesla MR unit (Symphony-Siemens). Diffusion MR imaging was done using spin echo type of single shot echo planar imaging (EPI) with b value of 0, 500 & 1000 sec/mm2. The apparent diffusion coefficient (ADC) map was reconstructed and ADC value was measured. The mean ADC values correlated with histo-pathological results as well as follow-up imaging results. Results: Adequate ADC maps were obtained in 47 patients. The mean ADC values were 3.4 ± 0.12 × 10-3 mm2/sec in cystic lesion, 2.23 ± 0.08 × 10-3 mm2/sec in hemangioma, 1.94 ± 0.05 × 10-3 mm2/sec in abscess, 1.72 ± 0.07 × 10-3 in focal nodular hyperplasia, 1.65 ± 0.06 × 10-3 mm2/sec in adenoma, 1.62 ± 0.07 × 10-3 mm2/sec in nodular regenerative hyperplasia. The mean ADC values were significantly different within benign hepatic focal lesions (P < 0.001). The differences between the mean ADC values of FNH, adenoma and NRH were not statistically significant (P < 0.23). Conclusion: Diffusion weighted MR imaging is a new imaging modality for diagnosis and characterization of different benign hepatic focal lesions, particularly in patient with renal dysfunction.

Pathology of spleen in chickens fed on a diet deficient in methionine

The purpose of this 42-day study was to investigate the effects of methionine deficiency on spleen by determining the relative weight, morphological changes of spleen, cell cycle and apoptosis of splenocytes, and oxidative markers of serum and spleen. One hundred and twenty one-day-old avian broilers were randomly divided into two groups and fed on a control diet (starter diet, methionine 0.50%;grower diet, methionine 0.40%) and methionine deficient diet (starter diet, methionine 0.26%;grower diet, methionine 0.28%) for 6 weeks. The relative weight of spleen was lighter in methionine deficiency than control group. Histopathologically, lymphopenia and congestion were observed. Ultrastructurally, there were more apoptosis lymphocytes in spleen and the mitochondria of lymphocytes were swelled in methionine deficiency. By flow cytometry, the G0/G1 phase of the cell cycle of the spleen was much higher (P < 0.01), and the S, G2+M phases and proliferating index were lower (P < 0.01) in methionine deficiency than in control group. And the percentage of apoptotic cells in the spleen was significantly increased in methionine deficiency (P < 0.01).The superoxide dismutase and glutathione peroxidase activities, and abilities to inhibit hydroxyl radicals were greatly decreased while the malondialdehyde contents were markedly increased in methionine deficiency. It was concluded that methionine deficiency could restraine the development of the spleen by cell cycle arrest and increased apoptosis, cause splenic lesions and reduce splenic antioxidant function. The splenic function should be finally impaired and then the immune function could be impacted in chickens.

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.

Evaluating the efficacy of percutaneous puncture biopsy guided by contrast-enhanced ultrasound for peripheral pulmonary lesions

BACKGROUND The incidence and mortality of lung cancer have increased annually.Accurate diagnosis can help improve therapeutic efficacy of interventions and prognosis.Percutaneous lung biopsy is a reliable method for the clinical diagnosis of lung cancer.Ultrasound-guided percutaneous lung biopsy technology has been widely promoted and applied in recent years.AIM To investigate the diagnostic value of contrast-enhanced ultrasound(CEUS)-guided percutaneous biopsy in peripheral pulmonary lesions.METHODS We retrospectively collected data on 237 patients with peripheral thoracic focal lesions who underwent puncture biopsy at Wuxi People’s Hospital.The patients were randomly divided into two groups:The CEUS-guided before lesion puncture group(contrast group)and conventional ultrasound-guided group(control group).Analyze the diagnostic efficacy of the puncture biopsy,impact of tumor size,and number of puncture needles and complications were analyzed and compared between the two groups.RESULTS Accurate pathological results were obtained for 92.83%(220/237)of peripheral lung lesions during the first biopsy,with an accuracy rate of 95.8%(113/118)in the contrast group and 89.9%(107/119)in the control group.The difference in the area under the curve(AUC)between the contrast and the control groups was not statistically significant(0.952 vs 0.902,respectively;P>0.05).However,when the lesion diameter≥5 cm,the diagnostic AUC of the contrast group was higher than that of the control group(0.952 vs 0.902,respectively;P<0.05).In addition,the average number of puncture needles in the contrast group was lower than that in the control group(2.58±0.53 vs 2.90±0.56,respectively;P<0.05).CONCLUSION CEUS guidance can enhance the efficiency of puncture biopsy of peripheral pulmonary lesions,especially for lesions with a diameter≥5 cm.Therefore,CEUS guidance has high clinical diagnostic value in puncture biopsy of peripheral focal lung lesions.

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.

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.

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 contrastenhanced 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 contrastenhanced 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.

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.

Focal liver lesions:Practical magnetic resonance imaging approach

With the widespread of cross-sectional imaging, a growth of incidentally detected focal liver lesions(FLL) has been observed. A reliable detection and characterization of FLL is critical for optimal patient management. Maximizing accuracy of imaging in the context of FLL is paramount in avoiding unnecessary biopsies, which may result in post-procedural complications. A tremendous development of new imaging techniques has taken place during these last years. Nowadays, Magnetic resonance imaging(MRI) plays a key role in management of liver lesions, using a radiation-free technique and a safe contrast agent profile. MRI plays a key role in the non-invasive correct characterization of FLL. MRI is capable of providing comprehensive and highly accurate diagnostic information, with the additional advantage of lack of harmful ionizing radiation. These properties make MRI the mainstay for the noninvasive evaluation of focal liver lesions. In this paper we review the state-of-the-art MRI liver protocol, briefly discussing different sequence types, the unique characteristics of imaging non-cooperative patients and discuss the role of hepatocyte-specific contrast agents. A review of the imaging features of the most common benign and malignant FLL is presented, supplemented by a schematic representation of a simplistic practical approach on MRI.

Contrast-enhanced ultrasonography in the evaluation of incidental focal liver lesions: A cost-effectiveness analysis

AIM To determine whether contrast-enhanced ultrasonography(CEUS) as the first-line method is more costeffective in evaluating incidentally discovered focal liver lesions(FLLs) than is computed tomography(CT) and magnetic resonance imaging(MRI). METHODS Between 2010 and 2015, our prospective study enrolled 459 patients with incidentally found FLLs. The biological nature of FLLs was assessed by CEUS in all patients. CT or MRI examinations were added in unclear cases. The sensitivity and specificity of CEUS were calculated. The total costs of CEUS examinations and of the added examinations performed in inconclusive cases were calculated. Afterwards, the theoretical expenses for evaluating incidentally discovered FLLs using CT or MRI as the first-line method were calculated. The resultswere compared. RESULTS The total cost of the diagnostic process using CEUS for all enrolled patients with FLLs was 75884 USD. When the expenses for additional CT and MRI examinations performed in inconclusive cases were added, the total cost was 90540 US dollar(USD). If all patients had been examined by CT or MR as the first-line method, the costs would have been 78897 USD or 384235 USD, respectively. The difference between the cost of CT and CEUS was 3013 USD(4%) and that between MRI and CEUS was 308352 USD(406.3%). We correctly described 97.06% of benign or malignant lesions, with 96.99% sensitivity and 97.09% specificity. Positive predictive value was 94.16% and negative predictive value was 98.52%. In cases with 4 and more lesions, malignancy is significantly more frequent and inconclusive findings significantly less frequent(P < 0.001).CONCLUSION While the costs of CEUS and CT in evaluating FLLs are comparable, CEUS examination is far more costeffective in comparison to MRI.

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.

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.

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.

Value of shear wave elastography with maximal elasticity in differentiating benign and malignant solid focal liver lesions

BACKGROUND It is important to differentiate benign and malignant focal liver lesions(FLLs)accurately.Despite the wide use and acceptance of shear wave elastography(SWE),its value for assessing the elasticity of FLLs and differentiating benign and malignant FLLs is still investigational.Previous studies of SWE for FLLs used mean elasticity as the parameter to reflect the stiffness of FLLs.Considering the inhomogeneity of tumor stiffness,maximal elasticity(Emax)might be the suitable parameter to reflect the stiffness of FLLs and to differentiate malignant FLLs from benign ones.AIM To explore the value of SWE with Emax in differential diagnosis of solid FLLs.METHODS We included 104 solid FLLs in 95 patients and 50 healthy volunteers.All the subjects were examined using conventional ultrasound(US)and virtual touch tissue quantification(VTQ)imaging.A diagnosis of benign or malignant FLL was made using conventional US.Ten VTQ values were acquired after 10 consecutive measurements for each FLL and each normal liver,and the largest value was recorded as Emax.RESULTS There were 56 cases of malignant FLLs and 48 cases of benign FLLs in this study.Emax of malignant FLLs(3.29±0.88 m/s)was significantly higher than that of benign FLLs(1.30±0.46 m/s,P<0.01)and that of livers in healthy volunteers(1.15±0.17 m/s,P<0.01).The cut-off point of Emax was 1.945,and the area under the curve was 0.978.The sensitivity and specificity of Emax were 92.9%and 91.7%,respectively,higher(but not significantly)than those of conventional US(80.4%for sensitivity and 81.3%for specificity).Combined diagnosis of conventional US and Emax using parallel testing improved the sensitivity to 100%with specificity of 75%.CONCLUSION SWE is a convenient and easy method to obtain accurate stiffness information of solid FLLs.Emax is useful for differential diagnosis of FLLs,especially in combination with conventional US.

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.

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.

Detection of focal liver lesions in cirrhotic liver using contrast-enhanced ultrasound

Patients with liver cirrhosis are at increased risk of hepatocellular carcinoma(HCC).Conventional or baseline ultrasound(BUS)is often used as the first-line tool for HCC surveillance or detection,but the accuracy of BUS in HCC detection or differentiation from other focal liver lesions(FLLs)is limited.Contrast-enhanced ultrasound(CEUS)represents a recent revolution in the field of ultrasonography and it has become increasingly important in the detection and evaluation of FLLs.In CEUS,HCC typically exhibits arterial hyper-enhancement and portal-venous washout represented by hypoenhanced lesions in the portal venous and late phases.The detection rate of HCC was significantly higher with CEUS compared with BUS.Even regenerative or some dysplastic nodules may exhibit arterial hyperenhancement as they are differentiated from HCC by its iso-enhancing pattern in portal and late phases.The contrast-enhancement patterns of other different types of benign and malignant FLLs,as well as their detection rates with CEUS,were also discussed.