Characterization Of Focal Liver Lesions Research Articles

Contrast-enhanced ultrasound (CEUS) of the liver : Critical evaluation of use in clinical routine diagnostics

Focal liver lesions are common incidental findings in abdominal ultrasound diagnostics. Characterization of focal liver lesions solely based on b‑mode and color duplex is not feasible in all cases. Using contrast-enhanced ultrasound (CEUS) it is possible to dynamically visualize the vascularization of focal liver lesions, which enables the characterization of benign and malignant liver tumors. The advantages of CEUS are that ultrasound contrast media do not show renal, hepatic or cardiac toxicity and do not influence the thyroid gland. The approach by fusion of CEUS and contrast-enhanced cross-sectional imaging combines the advantages of both imaging modalities. Using CEUS focal liver lesions can be characterized with adiagnostic accuracy greater than 90%. The use of CEUS has become an important imaging modality to evaluate unclear liver lesions. The use of CEUS provides vital information as a supplement to cross-sectional imaging and it has become an important tool in therapy planning, control and monitoring of malignant liver lesions.

Clinical Applications of Contrast-Enhanced Ultrasound in the Pediatric Work-Up of Focal Liver Lesions and Blunt Abdominal Trauma: A Systematic Review.

In pediatrics ultrasound has long been viewed more favorably than imaging that exposes patients to radiation and iodinated contrast or requires sedation. It is child-friendly and diagnostic capabilities have been improved with the advent of contrast-enhanced ultrasound (CEUS). The application of CEUS is indeed promising. However, no ultrasound contrast agent manufactured today is registered for pediatric use in Europe. The contrast agent SonoVue® has recently been approved by the FDA under the name of Lumason® to be used in hepatic investigations in adults and children. This article reviews the literature with respect to 2 specific applications of CEUS in children: 1) identification of parenchymal injuries following blunt abdominal trauma, and 2) classification of focal liver lesions. Applications were chosen through the CEUS guidelines published by the European Federation of Societies for Ultrasound in Medicine and Biology and World Federation for Ultrasound in Medicine and Biology. Literature was obtained by searching Medline and Pubmed Central (using Pubmed), Scopus database and Embase. CEUS proved to be an effective investigation in the hemodynamically stable child for identifying parenchymal injuries and for the characterization of focal liver lesions. CEUS showed comparable performance to CT and MRI with a specificity of 98% for identifying benign lesions and a negative predictive value of 100%. For the applications reviewed here, CEUS holds promising perspectives and can help reduce radiation exposure and use of iodinated contrast agents in pediatrics, thereby potentially reducing complications in routine imaging.

Intrasurgical dignity assessment ofhepatictumors using semi-quantitative strain elastography and contrast-enhanced ultrasound for optimisation of liver tumorsurgery.

To evaluate the efficacy of strain elastography (SE) using semi-quantitative measurement methods compared to constrast enhanced ultrasound during liver tumor surgery (Io-CEUS) for dignity assessment of focal liver lesions(FLL). Prospective data acquisition and retrospective analysis of US data of 100 patients (116 lesions) who underwent liver tumor surgery between 10/2010 and 03/2016. Retrospective reading of SE color patterns was performed establishing groups depending on dominant color (>50% blue = stiff, inhomogenous, >50% yellow/red/green = soft tissue). Semi-quantitative analysis was performed by Q-analysis based on a scale from 0 (soft) to 6 (stiff). 2 ROIs were placed centrally, 5 ROIs in the lesion's surrounding tissue. Io-CEUS was performed by bolus injection of 5-10 ml sulphurhexaflourid microbubbles evaluating wash-in- and -out- kinetics in arterial, portal venous and late phase. Histopathology after surgical resection served as goldstandard. 100 patients (m: 65, f: 35, mean age 60.5 years) with 116 liver lesions were included. Lesion's size ranged from 0.5 to 8.4 cm (mean 2.42 cm SD±1.44 cm). Postoperative histology showed 105 malignant and 11 benign lesions. Semi-quantitative analysis showed central indurations of >2.5 in 76/105 cases suggesting malignancy. 7 benign lesions displayed no central indurations correctly characterized benign by SE. ROC-analysis and Youden index showed a sensitivity of 72.4% and specificity of 63.6% assuming a cut-off of 2.5. Io-CEUS correctly characterized 103/105 as malignant. Sensitivity was 98%, specificity 72.7%. Strain elastography is a valuable tool for non-invasive characterization of FLLs. Semi-quantitative intratumoral stiffness values of >2.5 suggested malignancy. However, sensitivity of Io-CEUS in detecting malignant lesions was higher compared to SE. In conclusion SE should be considered for routine use during intraoperative US in addition to Io-CEUS for optimization of curative liver surgery.

Gd-EOB-DTPA-enhanced MR relaxometry for the detection and staging of liver fibrosis

Gd-EOB-DTPA, a liver-specific contrast agent with T1-shortening effects, is routinely used in clinical routine for detection and characterization of focal liver lesions and has recently received increasing attention as a tool for the quantitative analyses of liver function. We report the relationship between the extent of Gd-EOB-DTPA- induced T1 relaxation and the degree of liver fibrosis, which was assessed according to the METAVIR score. For the T1 relaxometry, a transverse 3D VIBE sequence with inline T1 calculation was acquired prior to and 20 minutes after Gd-EOB-DTPA administration. The reduction rates of the T1 relaxation time (rrT1) between the pre- and postcontrast images were calculated, and the optimal cutoff values for the fibrosis stages were determined with receiver operating characteristic (ROC) curve analyses. The rrT1 decreased with the severity of liver fibrosis and regression analysis revealed a significant correlation of the rrT1 with the stage of liver fibrosis (r = −0.906, p < 0.001). ROC analysis revealed sensitivities ≥78% and specificities ≥94% for the differentiation of different fibrosis stages. Gd-EOB-DTPA–enhanced T1 relaxometry is a reliable tool for both the detection of initial hepatic fibrosis and the staging of hepatic fibrosis.

Ultrasound Elastography Principles & Application in Liver

Elastography shows the biomechanical properties of the tissues whereas B-mode ultrasound shows their acoustic properties. These properties are not related to each other. Elastography can be considered a virtual palpation: under a stress, stiffer tissues show less longitudinal displacement and higher speed of transverse displacement. Elastography techniques are based or on the assessment of the longitudinal displacement of the tissue induced by a stress, as in strain elastography and acoustic radiation force impulse (ARFI) imaging, or on the assessment of the speed of the transverse displacement of the tissue as in shear wave elastography. In strain elastography a part of the body is compressed axially by pressing across its surface and the internal tissue displacement is converted to a strain image (percentage of deformation), because the percentage of deformation will be constant whereas displacement decays with depth. In the ARFI imaging the acoustic radiation force generates a localized displacement of a few microns in the ultrasound axial direction. ARFI generates also shear wave displacement at one point (point shear wave elastography) or along several lines (2D-shear wave elastography). Liver stiffness is directly related to liver fibrosis. Several studies and meta-analyses have assessed the accuracy of the available shear wave elastography (SWE) techniques, i.e. vibration controlled transient elastography (VCTE), point SWE and 2D-SWE, for the staging of liver fibrosis. VCTE was the first technique available and it needs a dedicated device that doesn't give a morphological assessment of the liver parenchyma. The advantages of the SWE techniques incorporated in ultrasound systems are that the same system can be used for the evaluation of morphologic changes or the detection of focal liver lesions and the B-mode image is a guidance for the stiffness assessment. Confounding factors should always be taken into account in the interpretation of the results, that should be evaluated in the clinical setting. In fact, liver stiffness increases in cases of acute hepatitis or transaminase flares, congestive heart failure, feeding and extrahepatic cholestasis. In patient with liver cirrhosis, liver stiffness is associated with the risk of decompensation, liver cancer, and death. Elastography could give additional information for the characterization of focal liver lesions, however the large overlap between values observed in benign and malignant lesions limits the use of the technique.

Imaging patterns and focal lesions in fatty liver: a pictorial review.

Non-alcoholic fatty liver disease is the most common cause of chronic liver disease and affects nearly one-third of US population. With the increasing trend of obesity in the population, associated fatty change in the liver will be a common feature observed in imaging studies. Fatty liver causes changes in liver parenchyma appearance on imaging modalities including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) and may affect the imaging characteristics of focal liver lesions (FLLs). The imaging characteristics of FLLs were classically described in a non-fatty liver. In addition, focal fatty change and focal fat sparing may also simulate FLLs. Knowledge of characteristic patterns of fatty change in the liver (diffuse, geographical, focal, subcapsular, and perivascular) and their impact on the detection and characterization of FLL is therefore important. In general, fatty change may improve detection of FLLs on MRI using fat suppression sequences, but may reduce sensitivity on a single-phase (portal venous) CT and conventional ultrasound. In patients with fatty liver, MRI is generally superior to ultrasound and CT for detection and characterization of FLL. In this pictorial essay, we describe the imaging patterns of fatty change in the liver and its effect on detection and characterization of FLLs on ultrasound, CT, MRI, and PET.

Contrast enhanced ultrasound features of hepatic cystadenoma and hepatic cystadenocarcinoma

Objective: Hepatic (biliary) cystic tumor (HBCT) is a rare focal cystic liver lesion, which has been rarely described in the literature. In our current multicenter, retrospective study, we aimed to analyze contrast enhanced ultrasound (CEUS) features and its diagnostic performance in histologically proved HBCT.Material and methods: Twenty-three patients with single HBCT were retrospectively analyzed. Histologically, 17 (73.9%) were benign hepatic (biliary) cystadenoma (HBCA), 6 (26.1%) were hepatic (biliary) cystadenocarcinoma (HBCAC). All CEUS examinations were assessed by two independent radiologists in consensus. Criteria of CEUS imaging evaluation included the contrast enhancement pattern of lesion (hypoenhancing, hyperenhancing, isoenhancing in comparison to the surrounding liver parenchyma) during the arterial, portal venous and late phases.Results: After injection of ultrasound contrast agents, most of the HBCTs (78.3%, 18/23) had typical honeycomb enhancement pattern of the cystic wall, septa or mural nodules. Comparing between HBCA and HBCAC, hyperenhancement of the honeycomb septa during the arterial phase was more common in HBCA (p = .047). However, hypoenhancement during the portal venous and late phases was the characteristic of HBCAC (p = .041).Conclusions: The EFSUMB algorithm for CEUS for characterization of solid focal liver lesions is also applicable to HBCT. CEUS evaluation can avoid further diagnostic investigations or invasive biopsy procedure.

Benign versus malignant focal liver lesions: Diagnostic value of qualitative and quantitative diffusion weighted MR imaging

Background and objectiveDiffusion-weighted imaging has an emerging role for assessment of focal and diffuse liver diseases. The aim of this study was to evaluate the diagnostic performance of DWI for characterization of focal liver lesions (FLLs). Patients and methodsThis prospective study included 40 consecutive patients with 64 focal liver lesions, who underwent MRI of the liver. All patients had one or more hepatic focal lesion of diameter more than 1cm. DWI was reviewed (b values of 0, 50 and 600s/mm2) and the mean ADC was calculated. ResultsQuantitative assessment using ADC map was more accurate (87.5%) than qualitative assessment using DWI (75%) in characterization of FLLs. Mean ADC values of malignant lesions (0.94+0.32×10−3mm2/s) were significantly lower than those of benign lesions (2.64+0.46×10−3mm2/s), (P<0.001). Using an ADC value above 1.6×10−3mm2/s offered the best accuracy in differentiation of malignant from benign lesions (86%). ConclusionDWI is a useful tool for FLLs characterization. Because of its known pitfalls and limitations, mainly the considerable overlap of ADCs values between solid benign and malignant lesions, it should be interpreted in combination with clinical data and conventional MRI sequences.

Evaluation of 2D-shear wave elastography for characterisation of focal liver lesions running title: 2D-SWE and liver lesions

Evaluation of 2D-shear wave elastography for characterisation of focal liver lesions running title: 2D-SWE and liver lesions

Avoiding Pitfalls in the Interpretation of Gadoxetic Acid–Enhanced Magnetic Resonance Imaging

Gadoxetic acid is extensively used in the following 3 main clinical situations: characterization of small nodules in patients with cirrhosis, preoperative staging of liver metastases, and characterization of incidentally discovered focal liver lesions. Owing to the rapid entry of gadoxetic acid into hepatocytes, the traditional features of liver tumors are modified on magnetic resonance (MR) imaging, especially during delayed phase sequences. Thus, although the added value of gadoxetic acid for the detection and characterization of focal liver lesions is now clear, its unique pharmacokinetics as well as the presence of mimicking and atypical lesions may lead to misdiagnoses. The goal of this article is to illustrate common and uncommon pitfalls associated with the use of gadoxetic acid-enhanced MR imaging. Moreover, additional MR imaging features that can help establish a correct diagnosis are described.

Magnetic Resonanance Imaging of the Liver (Including Biliary Contrast Agents)—Part 2: Protocols for Liver Magnetic Resonanance Imaging and Characterization of Common Focal Liver Lesions

Magnetic resonance imaging (MRI) is a fundamental tool for the noninvasive evaluation of liver pathologies. The anatomical position, the mobility with respiration, and the peculiar hemodynamics of the liver present several issues that have taken advantage from technological advances in MRI technology in the last decade, in particular regarding hardware, software, and contrast media (CM). We provided an overview of these topics in the first part of the review. MRI pulse sequences of clinical use in liver imaging can be divided into (1) T2-weighted sequences, for detection and characterization of focal and diffuse lesions without contrast, (2) T1-weighted sequences, with or without contrast injection, for further lesion characterization, and (3) additional techniques, such as diffusion-weighted imaging (DWI) and magnetic resonance cholangiopancreatography (MRCP). Most sequences have different names and abbreviations, and the reader is invited to find the respective commercial name specific for each vendor in appropriate references.1 The use of CM adds information on function and vascularity of liver parenchyma and focal lesions. The optimization of the technique for postcontrast studies and the basic concepts for characterization of focal liver lesions are briefly discussed in the following sections. MRI provides several advanced techniques for quantitative evaluation of diffuse liver disease. The complexity of these techniques is beyond the scope of this review, and only a brief description on magnetic resonance elastography (MRE), fat and iron quantification would be provided. At the end of our overview, we would discuss strategies to build basic liver protocols.

Role of MRI with hepatospecific contrast agent in the identification and characterization of focal liver lesions: pathological correlation in explanted livers.

To assess the diagnostic performance of magnetic resonance imaging (MRI) with gadoxetic acid in the identification of hepatocellular carcinoma (HCC) nodules by comparison with histological findings. In a cohort of patients suffering from cirrhosis of various etiologies (chronic hepatitis C virus (HCV) or hepatitis B virus (HBV), alcohol abuse, cryptogenic forms), we selected 17 patients affected by HCC who were eligible for liver transplantation on the basis of a computed-tomography (CT) total-body examination. Such patients also underwent an MRI examination under basal conditions, and with four dynamic phases, as well as a hepatobiliary phase acquired after at least 20min and recognized by the excretion of contrast agent into the bile duct, following intravenous administration of 0.05mol/kg of gadoxetic acid (gadoxetate disodium, Primovist(®); Bayer, Osaka, Japan). The MRI images were then evaluated in a double-blinded experimental setup by two radiologists experienced in imaging of the liver. The diagnosis of HCC was made in the presence of nodular lesions that showed typical or atypical enhancement patterns. The liver was subsequently explanted (on average 47.4days after MRI evaluation), dissected into 1-cm samples, and histologically evaluated according to the classification of Edmondson-Steiner. At the histopathological examination, 46 nodules were identified, on average 2.7 nodules for each patient. Of these, 37 were hepatocellular carcinomas, 3 were characterized by histologically unrecognizable complete necrosis, and 6 showed high-grade dysplasia. MRI with hepatospecific contrast medium showed inter-observer average values of sensitivity, specificity, and diagnostic accuracy of 94.6, 90, and 93.6%, respectively. In one case, a nodule was not identified by MRI with gadoxetic acid, even in the hepatospecific phase (false negative (FN)). This result could be implicated to the long time interval between the analysis and the explant (88days). In another case, there was an overdiagnosis of a HCC with a typical nodular pattern (false positive (FP)), but which most likely should have been attributed to a previous echinococcus cyst. MRI analysis, in combination with the study of the hepatobiliary phase, also showed a greater sensitivity, the same specificity, and a greater diagnostic accuracy compared to MRI evaluated only in the dynamic phases (with an average percentage between the two operators, respectively, of 75.7, 90, and 78%). MRI with gadoxetic acid shows a diagnostic accuracy superior to contrast-enhanced MRI, allowing for the diagnosis of additional lesions, and it could be considered as an imaging method to carry out a more appropriate management of waiting lists for liver transplants.

Split-Bolus Multidetector-Row Computed Tomography Technique for Characterization of Focal Liver Lesions in Oncologic Patients.

BackgroundIn oncologic patients, the liver is the most common target for metastases. An accurate detection and characterization of focal liver lesions in patients with known primary extrahepatic malignancy are essential to define management and prognosis.ObjectivesTo assess the diagnostic accuracy of the split-bolus multidetector-row computed tomography (MDCT) protocol in the characterization of focal liver lesions in oncologic patients.Patients and MethodsWe retrospectively analyzed the follow-up split-bolus 64-detector row CT protocol in 36 oncologic patients to characterize focal liver lesions. The split-bolus MDCT protocol by intravenous injection of two boluses of contrast medium combines the hepatic arterial phase (HAP) and hepatic enhancement during the portal venous phase (PVP) in a single-pass.ResultsThe split-bolus MDCT protocol detected 208 lesions and characterized 186 (89.4%) of them: typical hemangiomas (n = 9), atypical hemangiomas (n = 3), cysts (n = 78), hypovascular (n = 93) and hypervascular (n = 3) metastases. Twenty two (10.6%) hypodense lesions were categorized as indeterminate (≤5 mm). The mean radiation dose was 24.5±6.5 millisieverts (mSv).ConclusionThe designed split-bolus MDCT technique can be proposed alternatively to triphasic MDCT and in a single-pass to PVP in the initial staging and in the follow-up respectively in oncologic patients.

Magnetic resonance imaging of the cirrhotic liver in the era of gadoxetic acid.

Gadoxetic acid improves detection and characterization of focal liver lesions in cirrhotic patients and can estimate liver function in patients undergoing liver resection. The purpose of this article is to describe the optimal gadoxetic acid study protocol for the liver, the unique characteristics of gadoxetic acid, the differences between gadoxetic acid and extra-cellular gadolium chelates, and the differences in phases of enhancement between cirrhotic and normal liver using gadoxetic acid. We also discuss how to obtain and recognize an adequate hepatobiliary phase.

Differentiation of hepatocellular carcinoma from its various mimickers in liver magnetic resonance imaging: What are the tips when using hepatocyte-specific agents?

Hepatocellular carcinoma is the most common primary hepatic malignant tumor. With widespread use of liver imaging, various cirrhosis-related nodules are frequently detected in patients with chronic liver disease, while diverse hypervascular hepatic lesions are incidentally detected but undiagnosed on dynamic computed tomography and magnetic resonance imaging (MRI). However, use of hepatocyte-specific MR contrast agents with combined perfusion and hepatocyte-selective properties have improved diagnostic performance in detection and characterization of focal liver lesions. Meanwhile, the enhancement patterns observed during dynamic phases using hepatocyte-specific agents may be different from those observed during MRI using conventional extracellular fluid agents, leading to confusion in diagnosis. Therefore, we discuss useful tips for the differentiation of hepatocellular carcinoma from similar lesions in patients with and without chronic liver disease using liver MRI with hepatocyte-specific agents.

A Review of the Appropriateness of the Current Italian Guidelines for Noninvasive Imaging Assessment of Focal Liver Lesions.

In 2007 the Italian National Institute of Health issued Guidelines for the use of diagnostic imaging techniques in the detection and the characterization of focal liver lesions. Since the publication of these guidelines in 2008, several studies relating to this topic have been published. Thus, we felt the need to assess whether interval research and new advancements in diagnostic imaging have yielded new evidence that should modify the recommendations that were previously issued. The literature search confirmed the appropriateness of the current guidelines. Although most modalities did not show substantial changes, interval introduction of DW-MRI is a valuable technique with a high diagnostic accuracy in the detection and characterization of FLLs, and its sensitivity is higher when combined with MRI.

Contrast enhanced ultrasound for the diagnosis of liver hemangiomas - results of a Romanian multicentre study.

Contrast enhanced ultrasound (CEUS) has been proven to be a reliable method for the characterization of focal liver lesions (FLL). The aim of this paper was to evaluate the performance of CEUS for the diagnosis of liver hemangiomas in a large cohort of patients. We performed a multicentre prospective study which included successive CEUS examinations from fourteen centers from Romania. CEUS examinations were performed in de novo FLL, using low mechanical index ultrasound, following an intravenous bolus of 2.4 ml SonoVue. CEUS was considered conclusive for hemangioma if a typical pattern was present following contrast (centripetal fill in during the arterial phase, hyperenhanced lesion during venous and late phases). In all cases a reference method was available (contrast CT or MRI or biopsy). The trial was registered in clinicaltrials.gov (Identifier NCT01329458). During February 2011 - May 2015, 1153 CEUS examinations were performed for the evaluation of de novo FLL. Out of the 1153 de novo FLL, 238 cases were diagnosed as hemangiomas by CEUS (typical enhancing pattern). Contrast CT/MRI and biopsy diagnosed additional 24 hemangiomas. From the 238 cases diagnosed as hemangiomas by CEUS, in 11 the final diagnosis was different. Considering contrast CT/MRI and biopsy as reference methods, CEUS had 90.4% sensitivity, 98.8% specificity, 95.4% positive predictive value, 97.4% negative predictive value, resulting in 96.9% diagnostic accuracy for the diagnosis of hemangiomas. CEUS is a sensitive and very specific method for the diagnosis of hemangiomas.

Shear Wave Elastography of Focal Liver Lesion: Intraobserver Reproducibility and Elasticity Characterization.

The aim of the study was to evaluate the intraobserver reproducibility and to determine the elasticity characteristics of focal liver lesions (FLLs) by shear wave elastography (SWE). One hundred thirty-six FLLs in 118 patients were examined with SWE for quantitative and qualitative assessment of stiffness. Three SWE images were obtained for each lesion and liver parenchyma by 1 radiologist. Intraobserver reproducibility was assessed by intraclass correlation coefficients (ICCs). Patient and lesion factors that can affect the reproducibility were evaluated. For characterization of the lesion elasticity, the difference in stiffness between the groups of lesions was evaluated. The mean (SD) diameter and depth of the lesions were 3.98 (2.07) and 4.4 (1.59) cm, respectively. The ICC of intraobserver reproducibility was 0.763. Deep-seated lesions (≥6 cm; ICC, 0.621) showed significantly lower intraobserver reproducibility compared with superficial lesions (ICC, 0.793; P = 0.047). Stiffness values of malignant lesions (n = 85, 60.41 [47.81] kPa) were significantly higher than those of benign lesions (n = 51, 22.05 [17.24] kPa, P < 0.0001). Mean (SD) stiffness of hepatocellular carcinoma (45.72 [35.65] kPa) was significantly lower than that of metastasis (67.43 [43.39] kPa) and was significantly higher than benign FLLs (22.05 [17.24] kPa). However, mean (SD) lesion-parenchyma ratio of hepatocellular carcinoma (3.76 [4]) was not significantly different from that of benign FLLs (3.7 [3.77]). Overall, intraobserver reproducibility of SWE in evaluation of FLLs was excellent, but it can be affected by lesion depth. In addition, SWE is helpful in elasticity characterization of FLLs.

Functional MR imaging of the liver

The diagnostics of diffuse liver disease traditionally rely on liver biopsies and histopathological analysis of tissue specimens. However, a liver biopsy is invasive and carries some non-negligible risks, especially for patients with decreased liver function and those requiring repeated follow-up examinations. Over the last decades, magnetic resonance imaging (MRI) has developed into a valuable tool for the non-invasive characterization of focal liver lesions and diseases of the bile ducts. Recently, several MRI methods have been developed and clinically evaluated that also allow the diagnostics and staging of diffuse liver diseases, e.g. non-alcoholic fatty liver disease, hepatitis, hepatic fibrosis, liver cirrhosis, hemochromatosis and hemosiderosis. The sequelae of diffuse liver diseases, such as a decreased liver functional reserve or portal hypertension, can also be detected and quantified by modern MRI methods. This article provides the reader with the basic principles of functional MRI of the liver and discusses the importance in a clinical context.

Percutaneous real-time sonoelastography as a non-invasive tool for the characterization of solid focal liver lesions: A prospective study

BackgroundReal-time sonoelastography is currently used for the characterization of superficial solid lesions such as thyroid and breast masses. This study evaluates the usefulness of percutaneous sonoelastography for the characterization of solid focal liver lesions. Methods30 out of 43 patients with 38 known liver lesions were included in a prospective, diagnostic study. Qualitative analysis (pattern of deformation, elasticity type of liver tumour) and semi-quantitative measurements (strain ratio, hardness percentage, histogram) were evaluated. Sensitivity, specificity, positive and negative predictive values were calculated and the area under the receiver operating characteristics curve was constructed. ResultsPatterns A and C-D are specific of benign lesions and metastases respectively. The patterns for haemangiomas, focal nodular hyperplasia and metastases were significantly different to each other in terms of strain ratio, hardness percentage and histogram (p<0.05). A statistically significant difference (p<0.001) was observed between the median values of the 3 measured parameters for benign (1.02; 12%; 47) and malignant lesions (1.66; 65%; 20.5) respectively. The area under the receiver operating characteristics curve values for strain ratio, hardness percentage and histogram were 0.88, 0.89, and 0.86 respectively for cut-off values of 1.2, 45, and 30. ConclusionsBy percutaneous sonoelastography it is possible to differentiate benign versus malignant focal liver lesions, metastases in particular, with good diagnostic performance.