Assessment Of Focal Liver Lesions Research Articles

Quantitative time intensity curve analysis of contrast-enhanced ultrasound (CEUS) examinations for the assessment of focal liver lesions.

Contrast enhanced ultrasound (CEUS) is well-established for the characterization of focal liver lesions (FLLs). By using intravenous ultrasound contrast agents, followed by specific low mechanical index examinations, CEUS enables a high spatial and temporal resolution as well as a dynamic assessment of macro- and microvascularization down to the capillaries. Nevertheless, CEUS has the disadvantage of being examiner-dependent, so quantitative analysis of time-intensity curves in dynamic CEUS (D-CEUS) could provide further information. The aim of this article is to provide a general review of the current literature regarding the usefulness of D-CEUS in the assessment of FLLs.

Assessment of focal liver lesions using magnetic resonance imaging, with a comparison to histopathological findings

Assessment of focal liver lesions using magnetic resonance imaging, with a comparison to histopathological findings

Advantages and Limitations of Point Shear Wave Elastography and 2-Dimensional Shear Wave Elastography against PercutaneousLiver Biopsy for Assessing Focal Liver Lesions

BACKGROUND: Ultrasound based noninvasive techniques for the evaluation of tissue elasticity are becoming popular in practice. An accurate diagnosis of focal liver lesions (FLLs) is very important and essential for the adequate treatment and management of different conditions. AIM: The study aims to evaluate the advantages and limitations of Point Shear Wave Elastography and 2-dimensional Shear Wave Elastography against percutaneous liver biopsy for assessing focal liver lesions. METHODS: This document reviews the advantages and limitations of point shear wave elastography (pSWE) and 2-dimensional shear wave elastography (2D-SWE) against percutaneous liver biopsy for assessing focal liver lesions. RESULTS: Ultrasound elastography has shown promising results and plays an important role in the assessment of focal liver lesions but the lack of histological confirmation is a limitation, especially in cases of suspected FLLs. The Tru cut percutaneous liver biopsy has been proven as a very helpful method for an accurate histological diagnosis. The main disadvantage of this procedure is that is invasive and the complications may be life threatening. CONCLUSION: Noninvasive methods to aid clinical decisions are preferred by patients rather than liver biopsy. US elastography, in the form of pSWE, as well as 2D SWE has proved reliable for the evaluation of liver parenchyma. The investigation of pSWE and 2D-SWE for assessing the elasticity of focal liver lesions and their differentiating is still a challenging goal. Percutaneous liver biopsy provides an option for accurate histological confirmation of liver pathologies, particularly FLLs. It continues to be an important tool in the diagnosis, prognosis, and treatment of those affected with liver disorders.

Assessment of focal liver lesions in non-cirrhotic liver – expert opinion statement by the Swiss Association for the Study of the Liver and the Swiss Society of Gastroenterology

Focal liver lesions are common, with a prevalence up to 20%. The lesions must be evaluated in context of risk factors associated with malignancy. Risk factors include age >40 years, known current or past malignancy, presence of liver cirrhosis or chronic liver disease (i.e. suspected by elevated liver elastography measurement ≥8 kPa or FIB-4 score ≥1.3), unintentional weight loss, fever or night sweats, newly detected focal liver lesions, documented growth of focal liver lesions, current or past use of androgens (e.g. testosterone, oxymetholone, danazol), increased serum tumour markers (i.e. alpha-fetoprotein, carbohydrate antigen 19-9 [CA19-9], carcinoembryonic antigen [CEA]) and family history of malignancy. In patients without risk factors of malignancy, regional (non-)fatty changes, simple liver cysts and typical haemangiomas can be diagnosed by conventional ultrasound (without contrast). Conventional ultrasound Doppler is recommended to rule out vascular malformations such as portosystemic shunts. In all other cases of focal liver lesions, contrast-enhanced imaging is indicated for differentiation in benign and malignant dignity. Contrast-enhanced ultrasound (CEUS) as a first diagnostic step and contrast-enhanced magnetic resonance imaging (MRI) are accurate tests to diagnose haemangioma and focal nodular hyperplasia. Hepatocellular adenoma is diagnosed by contrast-enhanced MRI and/or histology. “Wash out” on CEUS is highly suspicious for a malignant focal liver lesion. Additional investigations aimed at identifying the primary tumour, as well as staging-computed tomography, MRI and/or histology may be necessary and should be decided on a case-by-case basis. A biopsy of focal liver lesions is indicated in cases of unclear dignity, malignant aspect and focal liver lesions of unclear origin as well as for guiding surgical and oncological management.

Qualitative And Quantitative Magnetic Resonance Imaging Assessment Of Focal Liver Lesions: A Study To Evaluate The Role Of Different MRI Sequences.

Background: Focal liver lesions have a broad differential diagnosis. MRI with its improved soft tissue characterization and newer sequences can significantly narrow the differentials especially when discriminating benign from malignant lesions. Methods: T1, T1 IN AND OUT OF PHASE, T2, LONG TE T2 AND Diffusion Weighted Imaging was done in 159 patients with USG documented focal liver lesion. Qualitative and quantitative assessment of ADC values and long TE images was done and a threshold for differentiating benign from malignant lesions was obtained. The MRI diagnosis was compared with final diagnosis obtained from histopathology in most cases or follow up and other tests (markers and RBC scan) were histopathology was not available. Sensitivity, specificity and accuracy of MRI sequences in differentiating various focal lesions were obtained. Results: T1 weighted images were useful for identifying fat, hemorrhage and iron within the lesions. T2 weighted imaging was able to correctly classify 82.0% lesions as malignant and 83.7% lesions as benign. Long TE T2 images were highly accurate in distinguishing haemangiomas and cysts from solid lesions. On diffusion-weighted (DW) imaging, 89.5% (i.e. 60 out of 67) lesions were correctly classified as malignant and 88.0% (i.e. 81 out of 92) lesions were correctly classified as benign. Threshold ADC value of 1.37 × 10-3 mm2/s is highly accurate for differentiating malignant from benign lesions. Conclusion: DWI is a sine qua non in liver lesion assessment allowing improved detection and characterization. Long TE T2 weighted imaging can accurately detect haemangiomas and cysts and rule out metastasis.

Quantitative magnetic resonance imaging for focal liver lesions: bridging the gap between research and clinical practice.

Magnetic resonance imaging (MRI) is highly important for the detection, characterization, and follow-up of focal liver lesions. Several quantitative MRI-based methods have been proposed in addition to qualitative imaging interpretation to improve the diagnostic work-up and prognostics in patients with focal liver lesions. This includes DWI with apparent diffusion coefficient measurements, intravoxel incoherent motion, perfusion imaging, MR elastography, and radiomics. Multiple research studies have reported promising results with quantitative MRI methods in various clinical settings. Nevertheless, applications in everyday clinical practice are limited. This review describes the basic principles of quantitative MRI-based techniques and discusses the main current applications and limitations for the assessment of focal liver lesions.

Hepatobiliary MRI Contrast Agents: Pattern Recognition Approach to Pediatric Focal Hepatic Lesions.

OBJECTIVE. The purposes of this article are to review currently available hepatobiliary contrast agents, discuss techniques for optimization of pediatric liver MRI with hepatobiliary contrast agents, and review the imaging features of several pediatric hepatic lesions, focusing on their assessment with hepatobiliary contrast agents. CONCLUSION. MRI is the preferred imaging modality for complete assessment of focal liver lesions in the pediatric population. Imaging with gadolinium-based hepatobiliary contrast agents yields beneficial information about many focal liver lesions encountered in pediatric patients.

Tips and Tricks in Contrast-Enhanced Ultrasound (CEUS) for the Characterization and Detection of Liver Malignancies.

Contrast-enhanced ultrasound (CEUS) has a high diagnostic accuracy in the assessment of focal liver lesions. Clinical context (presence of liver cirrhosis, history of other malignancy versus incidental finding) is crucial for the correct interpretation of CEUS findings. CEUS has to be preceded by structured anamnesis and clinical examination as well as accurate B-mode sonography. Metastases are the most common malignant liver lesions in a non-cirrhotic liver. According to their contrast enhancement in the arterial phase, metastases are categorized as hyper- and hypo-vascular metastases. A common feature of all metastatic lesions is washout of the contrast agent in the portal venous or late phase. In the context of liver cirrhosis, > 95 % of focal liver lesions are hepatocellular carcinomas (HCCs). HCCs typically show arterial phase hyperenhancement, followed by mild and gradual contrast washout occurring very late in the late phase. For intrahepatic cholangiocellular carcinoma (ICC), the pattern of contrast enhancement in the arterial phase can vary. However, all ICCs typically show early and pronounced washout. Other liver malignancies like lymphoma, angiosarcoma, epithelioid hemangioendothelioma and others are very rare. Except for the contrast washout seen in all liver malignancies, they do not display pathognomonic enhancement patterns upon CEUS. Thus, biopsy is indispensable for definite diagnosis of the tumor entity. Furthermore, CEUS is used for the detection of metastases and therapeutic monitoring after local ablative procedures. The examination procedure differs slightly depending on the specific indication (characterization, detection).

Correction to: Magnetic resonance with diffusion-weighted imaging improves assessment of focal liver lesions in patients with potentially resectable pancreatic cancer on CT.

The original version of this article, published on 19 January 2018, unfortunately contained a mistake.

Magnetic resonance with diffusion-weighted imaging improves assessment of focal liver lesions in patients with potentially resectable pancreatic cancer on CT.

To investigate added value of MRI to preoperative staging MDCT for evaluation of focal liver lesions (FLLs) in potentially resectable pancreatic ductal adenocarcinomas (PDACs). In patients with potentially resectable PDACs after staging MDCT (n=167), characteristics of FLLs were scored as benign, indeterminate or metastases on an MDCT set and combined MDCT and MRI set by two readers, independently. Size of hepatic lesions was measured and detection rate of hepatic metastasis unsuspected by MDCT and diagnostic yield of MRI for FLLs were assessed. Reader-averaged figure-of-merit (FOM) of the combined set was significantly higher than that of MDCT alone (0.94 vs. 0.86, p=.028). In the negative-on-CT group, the diagnostic yield of MRI was 1.5-2.3% (2/133 and 3/133 for readers 1 and 2, respectively). In the indeterminate-on-CT group, MRI yield was 10.5-13.6% (2/19 and 3/22) and in patients with suspicious-metastasis-on-CT, 8.3-26.7% (1/12 and 4/15). All lesions with false-positive and false-negative CT findings were ≤1 cm. In potentially resectable PDACs, addition of MRI with DWI can provide significantly better diagnostic performance in characterization of focal liver lesions, especially for small-sized (≤ 1 cm) MDCT-indeterminate or suspicious metastasis lesions, aiding in determination of appropriate operation candidates. • Addition of MRI provides better diagnostic performance in characterization of liver lesions. • Combined interpretation of MRI and MDCT provided less frequent indeterminate liver lesions. • Diagnostic yield of MRI was high in CT-indeterminate or suspicious metastatic lesions. • Operation candidates can be determined with greater confidence in potentially resectable PDACs.

Contrast-enhanced US Assessment of Focal Liver Lesions in Children.

Ultrasonography (US) is often the first line of imaging for the examination of children suspected of having liver lesions. However, gray-scale US with color Doppler imaging has limitations. The use of US contrast agents has recently been approved by the U.S. Food and Drug Administration (FDA). Compared with other imaging modalities, contrast material-enhanced US (CEUS) enables the assessment of contrast enhancement patterns with a higher temporal resolution and is therefore becoming a valuable alternative imaging technique. CEUS is advantageous owing to its high safety profile; lower cost, compared with the costs of conventional contrast-enhanced computed tomographic and magnetic resonance imaging examinations; reliability; and reproducibility. Furthermore, US examinations obviate the use of sedation, ionizing radiation, and iodinated or gadolinium-based contrast agents. All of these are desirable attributes for an imaging examination for children, the most vulnerable of patients. Focal liver lesions in children are commonly discovered incidentally, and this can pose a dilemma in terms of diagnosis and management. Owing to the FDA's recent approval of the use of a specific US contrast agent for evaluation of focal liver lesions in pediatric patients, CEUS can now be used as a problem-solving tool that complements conventional imaging examinations and aids in the follow-up of lesions. The temporal resolution with CEUS enables US images to readily depict the real-time internal vascularity of a lesion. The characterization of a lesion during different phases of enhancement improves diagnostic confidence and treatment. In this article, the authors review the composition, physiologic properties, and safety profile of CEUS; describe the technique for performing CEUS; and highlight the utility of this examination in the assessment of common focal liver lesions in children. Online supplemental material is available for this article. ©RSNA, 2017.

Diagnostic accuracy and interobserver variability of Dynamic Vascular Pattern (DVP) in primary liver malignancies - A simple semiquantitative tool for the analysis of contrast enhancement patterns.

Contrast-enhanced ultrasound (CEUS) is a valuable tool in the diagnostic approach of focal liver lesions, but occasionally subjective and observer-dependent. Semiquantitative evaluation of dynamic CEUS (DCEUS) with standardised software programmes such as Dynamic Vascular Pattern (DVP) could help to improve diagnostic accuracy and objectivity in liver tumour assessment. The present study aimed at evaluation of diagnostic accuracy of DVP in a clinical setting. DVP images of 52 focal liver lesions [30 hepatocellular carcinomas (HCCs), 15 intrahepatic cholangiocellular carcinomas (ICCs), 7 focal nodular hyperplasias (FNHs)] were analysed by four blinded observers with different levels of CEUS-experience. Diagnostic accuracies for the assessment of dignity and entity were evaluated. Mean sensitivity, specificity, positive and negative predictive value for detection of malignancy with DVP were 48.4% /67.8% /92.7% and 29.3%, respectively. Total diagnostic accuracies for dignity/entity were 63.9% /38.5% (HCC: 58.3% /25.8%; ICC: 73.3% /50%; FNH: 67.9% /67.9%). Interreader-agreement was moderate (κ= 0.42-0.58). Differential diagnosis between ICC and HCC was most challenging. Although developed to improve diagnostic accuracy and objectivity in the assessment of focal liver lesions, DVP alone seems insufficient for differential diagnosis of HCC, ICC and FNH and cannot replace the skills of an experienced observer.

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.

Intra-individual comparison of CAIPIRINHA VIBE technique with conventional VIBE sequences in contrast-enhanced MRI of focal liver lesions

PurposeTo evaluate the impact of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) volume interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique on image quality, reader confidence, and inter-observer agreement for the assessment of focal liver lesions in comparison with the standard VIBE approach. Material and methodsIn this IRB-approved intra-individual comparison study, abdominal arterial and portal-venous contrast-enhanced MRI studies were retrospectively analyzed in 38 patients with malignant liver lesions. Each patient underwent both CAIPIRINHA and conventional VIBE 3T MRI within 3 months, showing stable disease. Images were evaluated using 5-point rating scales by two blinded radiologists with more than 20 and 5 years of experience in MRI, respectively. Readers scored dignity of liver lesions and assessed which liver segments were affected by malignancy (ranging from 1=definitely benign/not affected to 5=definitely malignant/affected by malignancy). Readers also rated overall image quality, sharpness of intrahepatic veins, and diagnostic confidence (ranging from 1=poor to 5=excellent). ResultsReviewers achieved a higher inter-observer reliability using CAIPIRINHA when they reported which liver segments were affected by malignancy compared to traditional VIBE series (κ=0.62 and 0.54, respectively, p<0.05). Similarly, CAIPIRINHA showed a slightly higher inter-rater agreement for the dignity of focal liver lesions versus the standard VIBE images (κ=0.50 and 0.49, respectively, p<0.05). CAIPIRINHA series also scored higher in comparison to standard VIBE sequences (mean scores: image quality, 4.2 and 3.5; sharpness of intrahepatic vessels, 3.8 and 3.2, respectively, p<0.05) for both reviewers and allowed for higher subjective diagnostic confidence (ratings, 3.8 and 3.2, respectively, p<0.05). ConclusionCompared to the standard VIBE approach, CAIPIRINHA VIBE technique provides improved image quality and sharpness of intrahepatic veins, as well as higher diagnostic confidence. Additionally, this technique allows for higher inter-observer agreement when reporting focal liver lesions for both dignity and allocation.

Role of Contrast-Enhanced Ultrasound (CEUS) in Paediatric Practice: An EFSUMB Position Statement.

The use of contrast-enhanced ultrasound (CEUS) in adults is well established in many different areas, with a number of current applications deemed "off-label", but the use supported by clinical experience and evidence. Paediatric CEUS is also an "off-label" application until recently with approval specifically for assessment of focal liver lesions. Nevertheless there is mounting evidence of the usefulness of CEUS in children in many areas, primarily as an imaging technique that reduces exposure to radiation, iodinated contrast medium and the "patient-friendly" circumstances of ultrasonography. This position statement of the European Federation of Societies in Ultrasound and Medicine (EFSUMB) assesses the current status of CEUS applications in children and makes suggestions for further development of this technique.

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.

Fast semi-automatic segmentation of focal liver lesions in contrast-enhanced ultrasound, based on a probabilistic model

Assessment of focal liver lesions (FLLs) in contrast-enhanced ultrasound requires the delineation of the FLL in at least one frame of the acquired data, which is currently performed manually by experienced radiologists. Such a task leads to subjective results, is time-consuming and prone to misinterpretation and human error. This paper describes an attempt to improve this clinical practice by proposing a novel fast two-step method to automate the FLL segmentation, initialised only by a single seed point. Firstly, rectangular force functions are used to improve the accuracy and computational efficiency of an active ellipse model for approximating the FLL shape. Then, a novel probabilistic boundary refinement method is used to iteratively classify boundary pixels rapidly. The proposed method allows for faster and easier assessment of FLLs, whilst requiring less interaction, but producing results comparably consistent with manual delineations, and hence increasing the confidence of radiologists when making a diagnosis. Quantitative evaluation based on real clinical data, from two different European countries reflecting true clinical practice, demonstrates the value of the proposed method.

2091965 How Sensitive is the Computer Assisted Diagnostic Prototype for Malignancy Assessment of Focal Liver Lesions By Ceus?

2091965 How Sensitive is the Computer Assisted Diagnostic Prototype for Malignancy Assessment of Focal Liver Lesions By Ceus?

3.0 Tesla magnetic resonance imaging: A new standard in liver imaging?

An ever-increasing number of 3.0 Tesla (T) magnets are installed worldwide. Moving from the standard of 1.5 T to higher field strength implies a number of potential advantage and drawbacks, requiring careful optimization of imaging protocols or implementation of novel hardware components. Clinical practice and literature review suggest that state-of-the-art 3.0 T is equivalent to 1.5 T in the assessment of focal liver lesions and diffuse liver disease. Therefore, further technical improvements are needed in order to fully exploit the potential of higher field strength.

Clinical Implications of Non-Steatotic Hepatic Fat Fractions on Quantitative Diffusion-Weighted Imaging of the Liver

Diffusion-weighted imaging (DWI) is an important diagnostic tool in the assessment of focal liver lesions and diffuse liver diseases such as cirrhosis and fibrosis. Quantitative DWI parameters such as molecular diffusion, microperfusion and their fractions, are known to be affected when hepatic fat fractions (HFF) are higher than 5.5% (steatosis). However, less is known about the effect on DWI for HFF in the normal non-steatotic range below 5.5%, which can be found in a large part of the population. The aim of this study was therefore to evaluate the diagnostic implications of non-steatotic HFF on quantitative DWI parameters in eight liver segments. For this purpose, eleven healthy volunteers (2 men, mean-age 31.0) were prospectively examined with DWI and three series of in-/out-of-phase dual-echo spoiled gradient-recalled MRI sequences to obtain the HFF and T2*. DWI data were analyzed using the intravoxel incoherent motion (IVIM) model. Four circular regions (ø22.3 mm) were drawn in each of eight liver segments and averaged. Measurements were divided in group 1 (HFF≤2.75%), group 2 (2.75< HFF ≤5.5%) and group 3 (HFF>5.5%). DWI parameters and T2* were compared between the three groups and between the segments. It was observed that the molecular diffusion (0.85, 0.72 and 0.49 ×10−3 mm2/s) and T2* (32.2, 27.2 and 21.0 ms) differed significantly between the three groups of increasing HFF (2.18, 3.50 and 19.91%). Microperfusion and its fraction remained similar for different HFF. Correlations with HFF were observed for the molecular diffusion (r = −0.514, p<0.001) and T2* (−0.714, p<0.001). Similar results were obtained for the majority of individual liver segments. It was concluded that fat significantly decreases molecular diffusion in the liver, also in absence of steatosis (HFF≤5.5%). Also, it was confirmed that fat influences T2*. Determination of HFF prior to quantitative DWI is therefore crucial.