Liver stiffness measured by magnetic resonance elastography as a risk factor for hepatocellular carcinoma: a preliminary case-control study

Comparison between Intravoxel Incoherent Motion and Splenic Volumetry to Predict Hepatic Fibrosis Staging in Preoperative Patients

Intravoxel incoherent motion (IVIM) and splenic volumetry (SV) for hepatic fibrosis (HF) prediction have been reported to be effective. Our purpose is to compare the HF prediction of IVIM and SV in 67 patients with pathologically staged HF. SV was divided by body surface area (BSA). IVIM indices, such as slow diffusion-coefficient related to molecular diffusion (D), fast diffusion-coefficient related to perfusion in microvessels (D*), apparent diffusion-coefficient (ADC), and perfusion related diffusion-fraction (f), were calculated by two observers (R1/R2). D (p = 0.718 for R1, p = 0.087 for R2) and D* (p = 0.513, p = 0.708, respectively) showed a poor correlation with HF. ADC (p = 0.034, p = 0.528, respectively) and f (p < 0.001, p = 0.007, respectively) decreased as HF progressed, whereas SV/BSA increased (p = 0.015 for R1). The AUCs of SV/BSA (0.649-0.698 for R1) were higher than those of f (0.575-0.683 for R1 + R2) for severe HF (≥F3-4 and ≥F4), although AUCs of f (0.705-0.790 for R1 + R2) were higher than those of SV/BSA (0.628 for R1) for mild or no HF (≤F0-1). No significant differences to identify HF were observed between IVIM and SV/BSA. SV/BSA allows a higher estimation for evaluating severe HF than IVIM. IVIM is more suitable than SV/BSA for the assessment of mild or no HF.

Clinical application of Magnetic resonance elastography in hepatocellular carcinoma: from diagnosis to prognosis

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major public health problem worldwide. Liver fibrosis is closely correlated with liver functional reserve and the risk of HCC development. Meanwhile, malignant tumors generally have high cellularity compared to benign tumors, which results in increased stiffness. Magnetic resonance elastography (MRE) has emerged as a new non-invasive technique for assessing tissue stiffness with excellent diagnostic accuracy, not only for assessing liver fibrosis but also for measuring tumor stiffness. Recent studies provide new evidence that MRE may play an important role in the management of patients with HCC and show several novel clinical applications, such as predicting the development of HCC, differentiating between benign/malignant liver lesions (FLL) and HCC pathological grades, assessing treatment response, and predicting recurrence after treatment, although some findings are controversial. Therefore, we conducted this review to summarize these novel applications of MRE in HCC patients and also discuss their limitations and future advancement.

Magnetic resonance imaging for characterization of hepatocellular carcinoma metabolism

With a better understanding of the pathophysiological and metabolic changes in hepatocellular carcinoma (HCC), multiparametric and novel functional magnetic resonance (MR) and positron emission tomography (PET) techniques have received wide interest and are increasingly being applied in preclinical and clinical research. These techniques not only allow for non-invasive detection of structural, functional, and metabolic changes in malignant tumor cells but also characterize the tumor microenvironment (TME) and the interactions of malignant tumor cells with the TME, which has hypoxia and low pH, resulting from the Warburg effect and accumulation of metabolites produced by tumor cells and other cellular components. The heterogeneity and complexity of the TME require a combination of images with various parameters and modalities to characterize tumors and guide therapy. This review focuses on the value of multiparametric magnetic resonance imaging and PET/MR in evaluating the structural and functional changes of HCC and in detecting metabolites formed owing to HCC and the TME.

Liver fibrosis assessment: MR and US elastography

Elastography has emerged as a preferred non-invasive imaging technique for the clinical assessment of liver fibrosis. Elastography methods provide liver stiffness measurement (LSM) as a surrogate quantitative biomarker for fibrosis burden in chronic liver disease (CLD). Elastography can be performed either with ultrasound or MRI. Currently available ultrasound-based methods include strain elastography, two-dimensional shear wave elastography (2D-SWE), point shear wave elastography (pSWE), and vibration-controlled transient elastography (VCTE). MR Elastography (MRE) is widely available as two-dimensional gradient echo MRE (2D-GRE-MRE) technique. US-based methods provide estimated Young's modulus (eYM) and MRE provides magnitude of the complex shear modulus. MRE and ultrasound methods have proven to be accurate methods for detection of advanced liver fibrosis and cirrhosis. Other clinical applications of elastography include liver decompensation prediction, and differentiation of non-alcoholic steatohepatitis (NASH) from simple steatosis (SS). In this review, we briefly describe the different elastography methods, discuss current clinical applications, and provide an overview of advances in the field of liver elastography.

Assessing liver fibrosis distribution through liver elasticity estimates obtained using a biomechanical model of respiratory motion with magnetic resonance elastography

Objective. This study aimed to produce a three-dimensional liver elasticity map using the finite element method (FEM) and respiration-induced motion captured by T1-weighted magnetic resonance images (FEM-E-map) and to evaluate whether FEM-E-maps can be an imaging biomarker comparable to magnetic resonance elastography (MRE) for assessing the distribution and severity of liver fibrosis. Approach. We enrolled 14 patients who underwent MRI and MRE. T1-weighted MR images were acquired during shallow inspiration and expiration breath-holding, and the displacement vector field (DVF) between two images was calculated using deformable image registration. FEM-E-maps were constructed using FEM and DVF. First, three Poisson’s ratio settings (0.45, 0.49, and 0.499995) were validated and optimized to minimize the difference in liver elasticity between the FEM-E-map and MRE. Then, the whole and regional liver elasticity values estimated using FEM-E-maps were compared with those obtained from MRE using Pearson’s correlation coefficients. Spearman rank correlations and chi-square histograms were used to compare the voxel-level elasticity distribution. Main results. The optimal Poisson’s ratio was 0.49. Whole liver elasticity estimated using FEM-E-maps was strongly correlated with that measured using MRE (r = 0.96). For regional liver elasticity, the correlation was 0.84 for the right lobe and 0.82 for the left lobe. Spearman analysis revealed a moderate correlation for the voxel-level elasticity distribution between FEM-E-maps and MRE (0.61 ± 0.10). The small chi-square distances between the two histograms (0.11 ± 0.07) indicated good agreement. Significance. FEM-E-maps represent a potential imaging biomarker for visualizing the distribution of liver fibrosis using only T1-weighted images obtained with a common MR scanner, without any additional examination or special elastography equipment. However, additional studies including comparisons with biopsy findings are required to verify the reliability of this method for clinical application.

Response comparison of PLC and SLC with magnetic resonance elastography after TACE

The aim of this study was to detect a response difference in primary (PLC) and secondary liver tumors (SLC) with magnetic resonance elastography (MRE) after TACE therapy. Thirty-one patients (25/31 male; mean age 69.6 years [range: 39-85 years]) with repeated TACE therapy of HCC were compared with twenty-seven patients (27/27 female; mean age 61.2 years [range 39-81 years]) with repeated TACE therapy of metastatic liver disease due to breast cancer. Both groups underwent either one (n = 31) or two (n = 27) repetitive magnetic resonance imaging (MRI) and MRE exams in 4- to 6-week intervals using a 1.5-T-scanner. MRE-based liver stiffness and size measurements were evaluated in tumorous lesions and in healthy liver lobe controls. PLC showed a significantly larger tumor size compared to SLC (26.4 cm2 vs. 11 cm2, p = 0.007) and a higher degree of stiffness (5.8 kPa vs. 5.1 kPa, p = 0.04). Both tumors decreased in size during the cycles (PLC: p = 0.8 and SLC: p < 0.0001) and lesions showed an increase in stiffness (PLC: p = 0.002 and SLC: p = 0.006). MRE demonstrates that PLC and SLC have similar responses to TACE therapy. PLC had a greater increase in stiffness and SLC got smaller. An increasing stiffness and decrease in size could show a good response.

An MRI-Based Radiomic Model for Individualized Prediction of Hepatocellular Carcinoma in Patients With Hepatitis B Virus-Related Cirrhosis

Objective

To develop and validate a radiomic nomogram for individualized prediction of hepatocellular carcinoma (HCC) in HBV cirrhosis patients based on baseline magnetic resonance imaging examinations and clinical data.

Methods

364 patients with HBV cirrhosis from five hospitals were assigned to the training, internal validation, external validation-1 or external validation-2 cohort. All patients underwent baseline magnetic resonance image (MRI) scans and clinical follow-up within three-year time. Clinical risk factors and MRI-based features were extracted and analyzed. The radiomic signatures were built using the radiomics-score (Rad-score) that calculated for each patient as a linear weighted combination of selected MRI-based features. Prognostic performances of the clinical and radiomic nomograms were evaluated with Cox modeling in the training and validation cohorts.

Results

Eighteen features were selected for inclusion in the Rad-score prognostic model. The radiomic signature from multi-sequence MRI yielded a concordance index (C-index) of 0.710, 0.681, 0.632 and 0.658 in the training, internal validation, external validation-1, external validation-2 cohorts, respectively. Sex and Child-Turcotte-Pugh (CTP) class were the most prognostic clinical risk factors in univariate Cox proportional hazards analyses. The radiomic combined nomogram that integrated the radiomic signature with the clinical factors yielded a C-index of 0.746, 0.710, and 0.641 in the training, internal validation, and external validation-1 cohorts, respectively, which was an improvement over either the clinical nomogram or radiomic signature alone.

Conclusion

We developed an MRI-based radiomic combined nomogram with good discrimination ability for the individualized prediction of HCC in HBV cirrhosis patients within three-year time.

Magnetic resonance elastography of the liver: everything you need to know to get started

Magnetic resonance elastography (MRE) of the liver has emerged as the non-invasive standard for the evaluation of liver fibrosis in chronic liver diseases (CLDs). The utility of MRE in the evaluation of different CLD in both adults and children has been demonstrated in several studies, and MRE has been recommended by several clinical societies. Consequently, the clinical indications for evaluation of CLD with MRE have increased, and MRE is currently used as an add-on test during routine liver MRI studies or as a standalone test. To meet the increasing clinical demand, MRE is being installed in many academic and private practice imaging centers. There is a need for a comprehensive practical guide to help these practices to deliver high-quality liver MRE studies as well as troubleshoot the common issues with MRE to ensure smooth running of the service. This comprehensive clinical practice review summarizes the indications and provides an overview on why to use MRE, technical requirements, system set-up, patient preparation, acquiring the data, and interpretation.

A novel technique for automating stiffness measurement and emphasizing the main wave: Coherent-wave auto-selection (CHASE)

This study aims to develop and assess a new automated processing technique in MR elastography (MRE), namely coherent-wave auto-selection (CHASE). CHASE enables automatic selection of the region of interest (ROI) for stiffness measurement by extraction of the coherent wave region (CHASE ROI), and it improves the reconstruction of stiffness by a directional filter oriented along the main wave in each pixel (CHASE filtering). In this study, MRE of a phantom and of the liver of four healthy volunteers was performed. To investigate the potential of CHASE, this study assessed the CHASE according to three indices through the phantom study: 1) agreement on the ROI settings between CHASE and expert observers, 2) noise dependency, and 3) effect of the CHASE on stiffness variability within the CHASE ROI. The agreements on the ROI settings were analyzed by Cohen's kappa coefficient (κ). The noise dependency was analyzed by the mean absolute percentage errors (MAPEs) within the ROI between low (20%-80% amplitudes) and high vibration amplitudes (100% amplitude). The stiffness variability was assessed by standard deviation (SD) within the ROI. In the volunteer study, agreements on the ROI settings (or stiffness value) and stiffness variability within the CHASE ROI were assessed using κ-value (or intraclass correlation coefficient: ICC) and coefficient of variation, respectively. The results showed close agreement on the ROI settings and stiffness (κ-value: greater than 0.61 in both the phantom and volunteer studies, ICC: 0.97 in the volunteer study). The MAPEs within the CHASE ROI were much smaller than those in the whole region of the phantom (CHASE ROI vs. the whole region at 20% amplitude: 10.3% vs. 50.8%). Moreover, in both the phantom and volunteer studies, the stiffness variation within the CHASE ROI was smaller in the elastogram processed with CHASE filtering than in the unprocessed one. Our results demonstrated that the CHASE has high robustness against noise and the potential to provide ROI settings for stiffness measurement comparable to expert observers, as well as improve the reconstruction of stiffness.

Impact of axisymmetric deformation on MR elastography of a nonlinear tissue-mimicking material and implications in peri-tumour stiffness quantification

Solid tumour growth is often associated with the accumulation of mechanical stresses acting on the surrounding host tissue. Due to tissue nonlinearity, the shear modulus of the peri-tumoural region inherits a signature from the tumour expansion which depends on multiple factors, including the soft tissue constitutive behaviour and its stress/strain state. Shear waves used in MR-elastography (MRE) sense the apparent change in shear modulus along their propagation direction, thereby probing the anisotropic stiffness field around the tumour. We developed an analytical framework for a heterogeneous shear modulus distribution using a thick-shelled sphere approximation of the tumour and soft tissue ensemble. A hyperelastic material (plastisol) was identified to validate the proposed theory in a phantom setting. A balloon-catheter connected to a pressure sensor was used to replicate the stress generated from tumour pressure and growth while MRE data were acquired. The shear modulus anisotropy retrieved from the reconstructed elastography data confirmed the analytically predicted patterns at various levels of inflation. An alternative measure, combining the generated deformation and the local wave direction and independent of the reconstruction strategy, was also proposed to correlate the analytical findings with the stretch probed by the waves. Overall, this work demonstrates that MRE in combination with non-linear mechanics, is able to identify the apparent shear modulus variation arising from the strain generated by a growth within tissue, such as an idealised model of tumour. Investigation in real tissue represents the next step to further investigate the implications of endogenous forces in tissue characterisation through MRE.

Liver stiffness measured by magnetic resonance elastography in early recurrence of hepatocellular carcinoma after treatment: A protocol for systematic review and meta analysis

BACKGROUND

With high diagnostic accuracy, magnetic resonance elastography (MRE) is a noninvasive tool and can be adopted to measure liver stiffness (LS). In this study, meta-analysis was carried out to further evaluate whether LS measured by MRE can predict early recurrence in patients with hepatocellular carcinoma (HCC).

METHODS

PUBMED, EMBASE, Web of Science, China National Knowledge Infrastructure, and Cochrane Library database were searched for studies related to LS measured by MRE in the prediction of recurrence in patients with HCC. Survival outcome was estimated by hazard ratios and 95% confidence intervals. Meta-analysis was conducted with the Stata 16.0.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will provide evidence support for LS measured by MRE in predicting the recurrence of HCC.

ETHICS AND DISSEMINATION

The private information from individuals will not be published. This systematic review also should not damage participants' rights. Ethical approval is not available. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/ OSF.IO / SURH3.

Non-invasive assessment of cirrhosis using multiphasic dual-energy CT iodine maps: correlation with model for end-stage liver disease score

PURPOSE

To determine whether multiphasic dual-energy (DE) CT iodine quantitation correlates with the severity of chronic liver disease.

METHODS

We retrospectively included 40 cirrhotic and 28 non-cirrhotic patients who underwent a multiphasic liver protocol DECT. All three phases (arterial, portal venous (PVP), and equilibrium) were performed in DE mode. Iodine (I) values (mg I/ml) were obtained by placing regions of interest in the liver, aorta, common hepatic artery, and portal vein (PV). Iodine slopes (λ) were calculated as follows: (I_equilibrium-I_arterial)/time and (I_equilibrium-I_PVP)/time. Spearman correlations between λ and MELD scores were evaluated, and the area under the curve of the receiver operating characteristic (AUROC) was calculated to distinguish cirrhotic and non-cirrhotic patients.

RESULTS

Cirrhotic and non-cirrhotic patients had significantly different λ_{equilibrium-arterial} [IQR] for the caudate (λ = 2.08 [1.39-2.98] vs 1.46 [0.76-1.93], P = 0.007), left (λ = 2.05 [1.50-2.76] vs 1.51 [0.59-1.90], P = 0.002) and right lobes (λ = 1.72 [1.12-2.50] vs 1.13 [0.41-0.43], P = 0.003) and for the PV (λ = 3.15 [2.20-5.00] vs 2.29 [0.85-2.71], P = 0.001). λ_{equilibrium-PVP} were significantly different for the right (λ = 0.11 [- 0.45-1.03] vs - 0.44 [- 0.83-0.12], P = 0.045) and left lobe (λ = 0.30 [- 0.25-0.98] vs - 0.10 [- 0.35-0.24], P = 0.001). Significant positive correlations were found between MELD scores and λ_{equilibrium-arterial} for the caudate lobe (ρ = 0.34, P = 0.004) and λ_{equilibrium-PVP} for the caudate (ρ = 0.26, P = 0.028) and right lobe (ρ = 0.33, P = 0.007). AUROC in distinguishing cirrhotic and non-cirrhotic patients were 0.72 (P = 0.002), 0.71 (P = 0.003), and 0.75 (P = 0.001) using λ_{equilibrium-arterial} for the left lobe, right lobe, and PV, respectively. The λ_{equilibrium-PVP} AUROC of the right lobe was 0.73 (P = 0.001).

CONCLUSION

Multiphasic DECT iodine quantitation over time is significantly different between cirrhotic and non-cirrhotic patients, correlates with the MELD score, and it could potentially serve as a non-invasive measure of cirrhosis and disease severity with acceptable diagnostic accuracy.

Clinical and Molecular Prediction of Hepatocellular Carcinoma Risk

Prediction of hepatocellular carcinoma (HCC) risk becomes increasingly important with recently emerging HCC-predisposing conditions, namely non-alcoholic fatty liver disease and cured hepatitis C virus infection. These etiologies are accompanied with a relatively low HCC incidence rate (~1% per year or less), while affecting a large patient population. Hepatitis B virus infection remains a major HCC risk factor, but a majority of the patients are now on antiviral therapy, which substantially lowers, but does not eliminate, HCC risk. Thus, it is critically important to identify a small subset of patients who have elevated likelihood of developing HCC, to optimize the allocation of limited HCC screening resources to those who need it most and enable cost-effective early HCC diagnosis to prolong patient survival. To date, numerous clinical-variable-based HCC risk scores have been developed for specific clinical contexts defined by liver disease etiology, severity, and other factors. In parallel, various molecular features have been reported as potential HCC risk biomarkers, utilizing both tissue and body-fluid specimens. Deep-learning-based risk modeling is an emerging strategy. Although none of them has been widely incorporated in clinical care of liver disease patients yet, some have been undergoing the process of validation and clinical development. In this review, these risk scores and biomarker candidates are overviewed, and strategic issues in their validation and clinical translation are discussed.

MR elastography of liver: current status and future perspectives

Non-invasive evaluation of liver fibrosis has evolved over the last couple of decades. Currently, elastography techniques are the most widely used non-invasive methods for clinical evaluation of chronic liver disease (CLD). MR elastography (MRE) of the liver has been used in the clinical practice for nearly a decade and continues to be widely accepted for detection and staging of liver fibrosis. With MRE, one can directly visualize propagating shear waves through the liver and an inversion algorithm in the scanner automatically converts the shear wave properties into an elastogram (stiffness map) on which liver stiffness can be calculated. The commonly used MRE method, two-dimensional gradient recalled echo (2D-GRE) sequence has produced excellent results in the evaluation of liver fibrosis in CLD from various etiologies and newer clinical indications continue to emerge. Advances in MRE technique, including 3D MRE, automated liver elasticity calculation, improvements in shear wave delivery and patient experience, are promising to provide a faster and more reliable MRE of liver. Innovations, including evaluation of mechanical parameters, such as loss modulus, displacement, and volumetric strain, are promising for comprehensive evaluation of CLD as well as understanding pathophysiology, and in differentiating various etiologies of CLD. In this review, the current status of the MRE of liver in CLD are outlined and followed by a brief description of advanced techniques and innovations in MRE of liver.

Liver stiffness measured by MR elastography is a predictor of early HCC recurrence after treatment

OBJECTIVES

Magnetic resonance elastography (MRE) is a non-invasive tool for measuring liver stiffness (LS) with high diagnostic accuracy. This study investigated whether quantified LS by MRE could predict early recurrence of patients with hepatocellular carcinoma (HCC) within the Milan criteria.

METHODS

A prospectively collected cohort, which included the HCC patients who underwent MRE before treatment (an HCC-MRE cohort), was analyzed. In the HCC-MRE cohort, only patients under the Milan criteria, who underwent hepatic resection, radiofrequency ablation (RFA), or transarterial chemoembolization (TACE), were reviewed. We investigated whether LS assessed by MRE was an independent predictor of early recurrence using Cox regressions and Kaplan-Meier analyses.

RESULTS

A total of 192 HCC patients under the Milan criteria who underwent hepatic resection (n = 96), RFA (n = 23), or TACE (n = 73) were included. Higher LS ratings (kPa; hazard ratio [HR] = 1.12; 95% confidence interval [CI] = 1.01-1.25; p = 0.040) emerged as an independent risk factor for early tumor recurrence. In the subgroup analysis, higher LS ratings were associated with higher risks of early HCC recurrence in both the resection/RFA group (> 4.5 kPa; HR = 2.95; 95% CI = 1.26-6.94; p = 0.013) and the TACE group (> 6 kPa; HR = 2.94; 95% CI = 1.27-6.83; p = 0.012).

CONCLUSION

LS assessed by MRE was an independent predictor of early recurrence among HCC patients under the Milan criteria after achieving a complete response.

KEY POINTS

• Liver parenchymal stiffness measured by MRE predicts early recurrence of treated HCC under Milan criteria. • A liver stiffness > 5.5 kPa was associated with worse recurrence-free survival. • Patients with high pre-treatment LS may benefit from stringent follow-up.

Hepatobiliary phase hypointense nodule without arterial phase hyperenhancement as a risk factor for late recurrence (>1 year) of hepatocellular carcinoma after surgery

AIM

To evaluate the value of magnetic resonance imaging (MRI) features, including liver stiffness measured by magnetic resonance elastography (MRE) and the presence of hepatobiliary phase (HBP) hypointense nodule without arterial phase hyperenhancement (APHE), for predicting late recurrence (>1 year) after surgery for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This retrospective study included 124 consecutive patients who had undergone surgery for HCC and preoperative MRI. After excluding patients with early recurrence within 1 year after surgery, 89 patients were analysed. Preoperative MRI images were reviewed by a radiologist to record imaging findings, including (1) liver stiffness by MRE, (2) size of the HCCs, (3) number of HCCs, and (4) presence of HBP hypointense nodule without APHE. Pathological findings included tumour grade, vascular/biliary/capsule invasion, and fibrosis stage of the liver. Considering imaging/pathological findings and patients' characteristics as dependent variables, Cox proportional hazards model analysis was performed to identify independent factors associated with late recurrence after surgery.

RESULTS

The median follow-up period was 37.3 months. During follow-up, 29 patients (32.5%) developed late recurrence after surgery. In multivariate analysis, underlying liver disease (viral hepatitis) and presence of HBP hypointense nodules without APHE (p=0.010 and 0.033, respectively) were independently associated with disease-free survival (DFS). Kaplan-Meier analysis revealed that patients with HBP hypointense nodules without APHE had a significantly lower DFS rate than those without the nodule (39.2% versus 74.1% at 3 years after surgery, p=0.008).

CONCLUSION

The presence of HBP hypointense nodules without APHE was an indicator of late recurrence after surgery for HCC.

MRI-based risk factors of hepatocellular carcinoma in patients with chronic liver disease: A prospective observational study

BACKGROUND

MR-based metrics, including hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE), and liver stiffness as measured by MR elastography are useful markers to stratify the risk of hepatocellular carcinoma (HCC) development in chronic liver disease patients. However, prospective studies are needed to clarify their utility.

PURPOSE

To perform a risk analysis of HCC development in chronic liver disease patients, with a focus on MR-based biomarkers.

STUDY TYPE

Prospective.

SUBJECTS

Consecutive 110 cirrhotic patients (61 males, 49 females) without a history of HCC who matched the inclusion criteria.

FIELD STRENGTH/SEQUENCE

3T/3D gradient-echo T₁ -weighted images and MR elastography.

ASSESSMENT

Patients underwent MRI for HCC screening and attended follow-up appointments every 3 months. The primary endpoint was the development of hypervascular HCC. Patients were classified according to the presence of an HBP hypointense nodule without APHE (if present in the liver, the patient was classified in nonclean liver group; if absent, clean liver group), and stiffness value on MR elastography (soft liver, <4.0 kPa; stiff liver, ≥4.0 kPa) at the initial examination.

STATISTICAL TESTS

Risk factors were identified in univariate and multivariate Cox regression models. Incidence rates of HCC development were evaluated using the Kaplan-Meier method.

RESULTS

Patients were classified into clean-liver (n = 76) and nonclean-liver groups (n = 34), and into soft-liver (n = 53) and stiff-liver groups (n = 45). During the follow-up period (median, 21.0 months), 16 patients developed hypervascular HCC. Patients in the nonclean-liver group showed a higher incidence of hypervascular HCC than those in the clean-liver group (3-year HCC incidence rates: 50.4% and 5.7%, respectively; P < 0.05). A nonclean liver was independently associated with hypervascular HCC development (hazard ratio, 18.75; 95% confidence interval, 4.83-128.63; P < 0.0001), but stiff liver was not (1.91; 0.66-6.23; P = 0.23).

DATA CONCLUSION

An HBP hypointense nodule without APHE observed on a gadoxetic acid-enhanced MR image is a strong indicator of subsequent development of hypervascular HCC in patients with chronic liver disease.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;51:389-396.

Magnetic resonance elastography of liver and spleen: Methods and applications

The viscoelastic properties of the liver and spleen can be assessed with magnetic resonance elastography (MRE). Several actuators, MRI acquisition sequences and reconstruction algorithms have been proposed for this purpose. Reproducible results are obtained, especially when the examination is performed in standard conditions with the patient fasting. Accurate staging of liver fibrosis can be obtained by measuring liver stiffness or elasticity with MRE. Moreover, emerging evidence shows that assessing the tissue viscous parameters with MRE is useful for characterizing liver inflammation, non-alcoholic steatohepatitis, hepatic congestion, portal hypertension, and hepatic tumors. Further advances such as multifrequency acquisitions and compression-sensitive MRE may provide novel quantitative markers of hepatic and splenic mechanical properties that may improve the diagnosis of hepatic and splenic diseases.

Clinical application of magnetic resonance elastography in chronic liver disease

Recent evidence highlighted that the accurate assessment of liver fibrosis is important for evaluating the progression of chronic liver disease. During the past decade, many non-invasive methods have been developed to reduce the need for core-needle biopsy in fibrosis staging and to overcome its limitations, such as invasiveness, high cost, low reproducibility, and poor patient consent. The diagnostic performance of magnetic resonance elastography (MRE) is promising for use in clinical practice to evaluate not only liver fibrosis, but also survival and major clinical end-points such as liver decompensation, portal hypertension, development of hepatocellular carcinoma, and surgical outcomes. Together with other clinical markers, MRE can be used to better categorize patients with advanced fibrosis and cirrhosis, and assign them to different classes of risk for significant clinical outcomes. This review discusses clinical applications of MRE in the management strategy of patients with chronic liver disease.

Quantitative estimation of progression of chronic liver disease using gadoxetate disodium-enhanced magnetic resonance imaging

AIM

The purpose of this study was to determine whether the liver stiffness (LS) measured on magnetic resonance (MR) elastography can be estimated by a combination of gadoxetate disodium-enhanced MR imaging (EOB-MRI) and ordinary blood tests.

METHODS

We evaluated 33 consecutive patients with suspected liver disease who underwent EOB-MRI using a Differential Subsampling with Cartesian Ordering MR sequence and MR elastography using a 1.5-T MR system in this prospective study. A stepwise multiple linear regression model analysis of LS was performed using various predictive values obtained from two-in-one-uptake, two-compartment model analysis of EOB-MRI (velocity constants of arterial inflow [K_1a ], portal venous inflow [K_1p ], hepatocellular uptake [K_i ]), and ordinary blood test results (blood platelet count, serum albumin level [ALB], total serum bilirubin level [T-BIL], and prothrombin time [PT%]).

RESULTS

Multiple linear regression model analysis revealed that hepatic perfusion-uptake index (HPUI = -K_1a  + K_1p  + K_i ) (P < 0.0001), albumin-bilirubin linear predictor (ALBI-LP = 0.66 × log₁₀ T-BIL - 0.085 × ALB) (P = 0.034), and blood platelet count (P = 0.046) were significant independent predictors of LS (r = 0.863). The area under receiver operator characteristics curve of multiple linear regression model in prediction of the liver stiffness corresponding to higher (LS > 5.0 kPa) and lower (LS < 4.2 kPa) risk for developing hepatocellular carcinoma were 0.956 and 0.938, respectively.

CONCLUSION

LS can be estimated quantitatively with the use of HPUI obtained from compartment model analysis of EOB-MRI combined with ALBI-LP and blood platelet count.

Liver Fibrosis Quantification by Magnetic Resonance Imaging

Liver fibrosis is a hallmark of chronic liver disease characterized by the excessive accumulation of extracellular matrix proteins. Although liver biopsy is the reference standard for diagnosis and staging of liver fibrosis, it has some limitations, including potential pain, sampling variability, and low patient acceptance. Hence, there has been an effort to develop noninvasive imaging techniques for diagnosis, staging, and monitoring of liver fibrosis. Many quantitative techniques have been implemented on magnetic resonance imaging (MRI) for this indication. The most widely validated technique is magnetic resonance elastography, which aims to measure viscoelastic properties of the liver and relate them to fibrosis stage. Several additional MRI methods have been developed or adapted to liver fibrosis quantification. Diffusion-weighted imaging measures the Brownian motion of water molecules which is restricted by collagen fibers. Texture analysis assesses the changes in the texture of liver parenchyma associated with fibrosis. Perfusion imaging relies on signal intensity and pharmacokinetic models to extract quantitative perfusion parameters. Hepatocellular function, which decreases with increasing fibrosis stage, can be estimated by the uptake of hepatobiliary contrast agents. Strain imaging measures liver deformation in response to physiological motion such as cardiac contraction. T1ρ quantification is an investigational technique, which measures the spin-lattice relaxation time in the rotating frame. This article will review the MRI techniques used in liver fibrosis staging, their advantages and limitations, and diagnostic performance. We will briefly discuss future directions, such as longitudinal monitoring of disease, prediction of portal hypertension, and risk stratification of hepatocellular carcinoma.

Noninvasive imaging of hepatocellular carcinoma: From diagnosis to prognosis

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major public health problem worldwide. Hepatocarcinogenesis is a complex multistep process at molecular, cellular, and histologic levels with key alterations that can be revealed by noninvasive imaging modalities. Therefore, imaging techniques play pivotal roles in the detection, characterization, staging, surveillance, and prognosis evaluation of HCC. Currently, ultrasound is the first-line imaging modality for screening and surveillance purposes. While based on conclusive enhancement patterns comprising arterial phase hyperenhancement and portal venous and/or delayed phase wash-out, contrast enhanced dynamic computed tomography and magnetic resonance imaging (MRI) are the diagnostic tools for HCC without requirements for histopathologic confirmation. Functional MRI techniques, including diffusion-weighted imaging, MRI with hepatobiliary contrast agents, perfusion imaging, and magnetic resonance elastography, show promise in providing further important information regarding tumor biological behaviors. In addition, evaluation of tumor imaging characteristics, including nodule size, margin, number, vascular invasion, and growth patterns, allows preoperative prediction of tumor microvascular invasion and patient prognosis. Therefore, the aim of this article is to review the current state-of-the-art and recent advances in the comprehensive noninvasive imaging evaluation of HCC. We also provide the basic key concepts of HCC development and an overview of the current practice guidelines.

Quantitative Elastography Methods in Liver Disease: Current Evidence and Future Directions

Chronic liver diseases often result in the development of liver fibrosis and ultimately, cirrhosis. Treatment strategies and prognosis differ greatly depending on the severity of liver fibrosis, thus liver fibrosis staging is clinically relevant. Traditionally, liver biopsy has been the method of choice for fibrosis evaluation. Because of liver biopsy limitations, noninvasive methods have become a key research interest in the field. Elastography enables the noninvasive measurement of tissue mechanical properties through observation of shear-wave propagation in the tissue of interest. Increasing fibrosis stage is associated with increased liver stiffness, providing a discriminatory feature that can be exploited by elastographic methods. Ultrasonographic (US) and magnetic resonance (MR) imaging elastographic methods are commercially available, each with their respective strengths and limitations. Here, the authors review the technical basis, acquisition techniques, and results and limitations of US- and MR-based elastography techniques. Diagnostic performance in the most common etiologies of chronic liver disease will be presented. Reliability, reproducibility, failure rate, and emerging advances will be discussed. ^© RSNA, 2018 Online supplemental material is available for this article.

Risk factors and prevention of hepatocellular carcinoma in the era of precision medicine

Patients who develop chronic fibrotic liver disease, caused by viral or metabolic aetiologies, are at a high risk of developing hepatocellular carcinoma (HCC). Even after complete HCC tumour resection or ablation, the carcinogenic tissue microenvironment in the remnant liver can give rise to recurrent de novo HCC tumours, which progress into incurable, advanced-stage disease in most patients. Thus, early detection and prevention of HCC development is, in principle, the most impactful strategy to improve patient prognosis. However, a "one-size-fits-all" approach to HCC screening for early tumour detection, as recommended by clinical practice guidelines, is utilised in less than 20% of the target population, and the performance of screening modalities, including ultrasound and alpha-fetoprotein, is suboptimal. Furthermore, optimal screening strategies for emerging at-risk patient populations, such as those with chronic hepatitis C after viral cure, or those with non-cirrhotic, non-alcoholic fatty liver disease remain controversial. New HCC biomarkers and imaging modalities may improve the sensitivity and specificity of HCC detection. Clinical and molecular HCC risk scores will enable precise HCC risk prediction followed by tailoured HCC screening of individual patients, maximising cost-effectiveness and optimising allocation of limited medical resources. Several aetiology-specific and generic HCC chemoprevention strategies are evolving. Epidemiological and experimental studies have identified candidate chemoprevention targets and therapies, including statins, anti-diabetic drugs, and selective molecular targeted agents, although their clinical testing has been limited by the lengthy process of cancer development that requires long-term, costly studies. Individual HCC risk prediction is expected to overcome the challenge by enabling personalised chemoprevention, targeting high-risk patients for precision HCC prevention and substantially improving the dismal prognosis of HCC.

Cancer Metabolism and Tumor Heterogeneity: Imaging Perspectives Using MR Imaging and Spectroscopy

Cancer cells reprogram their metabolism to maintain viability via genetic mutations and epigenetic alterations, expressing overall dynamic heterogeneity. The complex relaxation mechanisms of nuclear spins provide unique and convertible tissue contrasts, making magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) pertinent imaging tools in both clinics and research. In this review, we summarized MR methods that visualize tumor characteristics and its metabolic phenotypes on an anatomical, microvascular, microstructural, microenvironmental, and metabolomics scale. The review will progress from the utilities of basic spin-relaxation contrasts in cancer imaging to more advanced imaging methods that measure tumor-distinctive parameters such as perfusion, water diffusion, magnetic susceptibility, oxygenation, acidosis, redox state, and cell death. Analytical methods to assess tumor heterogeneity are also reviewed in brief. Although the clinical utility of tumor heterogeneity from imaging is debatable, the quantification of tumor heterogeneity using functional and metabolic MR images with development of robust analytical methods and improved MR methods may offer more critical roles of tumor heterogeneity data in clinics. MRI/MRS can also provide insightful information on pharmacometabolomics, biomarker discovery, disease diagnosis and prognosis, and treatment response. With these future directions in mind, we anticipate the widespread utilization of these MR-based techniques in studying in vivo cancer biology to better address significant clinical needs.

Magnetic resonance elastography (MRE) in cancer: Technique, analysis, and applications

Tissue mechanical properties are significantly altered with the development of cancer. Magnetic resonance elastography (MRE) is a noninvasive technique capable of quantifying tissue mechanical properties in vivo. This review describes the basic principles of MRE and introduces some of the many promising MRE methods that have been developed for the detection and characterization of cancer, evaluation of response to therapy, and investigation of the underlying mechanical mechanisms associated with malignancy.

The role of sonoelastography in planning percutaneous biopsy of soft tissue tumours

The aim of this study was to evaluate whether compression elastography has a useful role in the planning of percutaneous ultrasound-guided biopsies of soft tissue tumours. Consecutive patients were evaluated in the sarcoma clinic after their initial imaging work-up, involving ultrasound and MR. The multi-disciplinary team decided when percutaneous biopsy for histology was required, and this was performed in the multi-disciplinary clinic using ultrasound guidance. An experienced sarcoma radiologist performed the ultrasound with compression elastography in all cases. Grey scale imaging was used to predict the needle track for each biopsy and routinely, two passes were made into each lesion. In this study, the track for the second pass was predicted from the elastogram, aiming for a stiff (blue) area within the lesion. The samples were separately potted in formalin and sent to the sarcoma pathologist. Pathology reports for each sample were assessed to evaluate whether the elastographic blue targets yielded any specific diagnostic quality; 157 biopsies were performed in separate patients, including two passes per patient as per routine protocol; 107 (68.1%) were benign lesions and 50 (31.9%) were malignancies. In the benign group, 16 (14.9%) showed significant blue areas in the lesion. However, nine of these were thought to be artefactual, as they showed grey scale characteristics of complex cysts. Positive histology was recorded in all the blue areas, but in the benign lesions positivity was not seen solely in the blue areas; 14 (28%) in the malignant group showed blue areas in the lesion and five biopsies were positive in blue areas only. Overall, the blue target yielded the only positive tissue in 10% of the malignancies, equating to 3% of the whole study population. The p value was 0.008829 for positive histology for malignancy from blue areas only.

Comparison of magnetic resonance elastography and diffusion-weighted imaging for differentiating benign and malignant liver lesions

OBJECTIVES

Comparison of magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI) for differentiating malignant and benign focal liver lesions (FLLs).

METHODS

Seventy-nine subjects with 124 FLLs (44 benign and 80 malignant) underwent both MRE and DWI. MRE was performed with a modified gradient-echo sequence and DWI with a free breathing technique (b = 0.500). Apparent diffusion coefficient (ADC) maps and stiffness maps were generated. FLL mean stiffness and ADC values were obtained by placing regions of interest over the FLLs on stiffness and ADC maps. The accuracy of MRE and DWI for differentiation of benign and malignant FLL was compared using receiver operating curve (ROC) analysis.

RESULTS

There was a significant negative correlation between stiffness and ADC (r = -0.54, p < 0.0001) of FLLs. Malignant FLLs had significantly higher mean stiffness (7.9kPa vs. 3.1kPa, p < 0.001) and lower mean ADC (129 vs. 200 × 10(-3)mm(2)/s, p < 0.001) than benign FLLs. The sensitivity/specificity/positive predictive value/negative predictive value for differentiating malignant from benign FLLs with MRE (cut-off, >4.54kPa) and DWI (cut-off, <151 × 10(-3)mm(2)/s) were 96.3/95.5/97.5/93.3% (p < 0.001) and 85/81.8/88.3/75% (p < 0.001), respectively. ROC analysis showed significantly higher accuracy for MRE than DWI (0.986 vs. 0.82, p = 0.0016).

CONCLUSION

MRE is significantly more accurate than DWI for differentiating benign and malignant FLLs.

KEY POINTS

• MRE is superior to DWI for differentiating benign and malignant focal liver lesions. • Benign lesions with large fibrous components may have higher stiffness with MRE. • Cholangiocarcinomas tend to have higher stiffness than hepatocellular carcinomas. • Hepatocellular adenomas tend to have lower stiffness than focal nodular hyperplasia. • MRE is superior to conventional MRI in differentiating benign and malignant liver lesions.

Stratification of patients with liver fibrosis using dual-energy CT

Assessing the severity of liver fibrosis has direct clinical implications for patient diagnosis and treatment. Liver biopsy, typically considered the gold standard, has limited clinical utility due to its invasiveness. Therefore, several imaging-based techniques for staging liver fibrosis have emerged, such as magnetic resonance elastography (MRE) and ultrasound elastography (USE), but they face challenges that include limited availability, high cost, poor patient compliance, low repeatability, and inaccuracy. Computed tomography (CT) can address many of these limitations, but is still hampered by inaccuracy in the presence of confounding factors, such as liver fat. Dual-energy CT (DECT), with its ability to discriminate between different tissue types, may offer a viable alternative to these methods. By combining the "multi-material decomposition" (MMD) algorithm with a biologically driven hypothesis we developed a method for assessing liver fibrosis from DECT images. On a twelve-patient cohort the method produced quantitative maps showing the spatial distribution of liver fibrosis, as well as a fibrosis score for each patient with statistically significant correlation with the severity of fibrosis across a wide range of disease severities. A preliminary comparison of the proposed algorithm against MRE showed good agreement between the two methods. Finally, the application of the algorithm to longitudinal DECT scans of the cohort produced highly repeatable results. We conclude that our algorithm can successfully stratify patients with liver fibrosis and can serve to supplement and augment current clinical practice and the role of DECT imaging in staging liver fibrosis.

Three-Tesla magnetic resonance elastography for hepatic fibrosis: Comparison with diffusion-weighted imaging and gadoxetic acid-enhanced magnetic resonance imaging

AIM: To evaluate the feasibility of 3-Tesla magnetic resonance elastography (MRE) for hepatic fibrosis and to compare that with diffusion-weighted imaging (DWI) and gadoxetic acid-enhanced magnetic resonance (MR) imaging.

METHODS: Forty-two patients were included in the study. On MRE, mean stiffness values were measured on the elastograms in kilopascals. The apparent diffusion coefficient (ADC) of the liver was measured using DWI. On gadoxetic acid enhanced MR, the contrast enhancement index (CEI) was calculated as signal intensity (SI)_post/SI_pre, where SI_post is liver-to-muscle SI ratio on hepatobiliary phase images and SI_pre is that on nonenhanced images. Correlation between aspartate aminotransferase to the platelet ratio index (APRI) and three MR parameters was assessed. Each MR parameter was compared between a hepatic fibrosis (HF) group and non-hepatic fibrosis (nHF) group.

RESULTS: Liver stiffness showed strong positive correlation with APRI [Spearman correlation coeffiecient (r) = 0.773, P < 0.0001], while ADC and CEI showed weak or prominent negative correlation (r = -0.28 and -0.321, respectively). In the HF group, only liver stiffness showed strong correlation with APRI (r = 0.731, P < 0.0001). Liver stiffness, ADC, and APRI were significantly different between the HF group and nHF group.

CONCLUSION: MRE at 3-Tesla could be a feasible method for the assessment of hepatic fibrosis.

Sonoelastography for qualitative and quantitative evaluation of superficial soft tissue lesions: a feasibility study

OBJECTIVES

To evaluate the feasibility of qualitative and quantitative analysis using sonoelastography (SE) for differentiating between benign and malignant superficial soft-tissue lesions.

METHODS

For this prospective study, 32 patients with superficial soft-tissue lesions detected with grey-scale ultrasound and colour and/or power Doppler ultrasound were evaluated between October 2011 and December 2012. Qualitative analysis: visual grading system was adopted according to colour variation (red-soft, green-medium, blue-hard). Quantitative analysis: median and fraction area of each colour were computed within a region of interest. Differences between fraction areas and median values in compression and decompression phases were calculated. Reference standard: histological findings.

RESULTS

Twelve out of 32 lesions (37.5%) were malignant. Intraclass correlation coefficient (ICC) was 0.989 (95% confidence interval [CI] 0.980-0.994, P < 0.01) with optimal reliability. Area under the curve was 0.823 (95% CI 0.677-0.969) and 0.958 (95% CI 0.989-1.019) for blue and blue area differences, and 0.777 (95% CI 0.615-0.939) and 0.629 (95% CI 0.426-0.833) for red and red area differences, respectively. Blue variations predicted malignancy more accurately (variation ≥0.431: 100% sensitivity, 80% specificity); the blue area difference was highly accurate.

CONCLUSIONS

Preliminary results showed good correlations between SE and reference standards. SE could be useful in the evaluation of superficial soft tissue lesions.

KEY POINTS

• Sonoelastography helps clarify ambiguous soft-tissue lesions identified using conventional ultrasound techniques. • Addition of this tool increases the diagnostic accuracy of ultrasound. • Sonoelastography provides both qualitative and quantitative analysis. • Sonoelastography may help clinicians improve patient care.

[Organizational characteristics of treatment for chronic hepatitis in Hungary: Hepatitis Registry and Priority Index]

Hepatitis Registry was developed by the Hepatology Section of the Hungarian Gastroenterology Society with the contribution of the Foundation for Liver Patients. The main task was to register all interferon based treatments of chronic hepatitis C and B and to facilitate the preauthorization process. The registry helped to clarify the number and characteristics of hepatitis C patients waiting for triple therapy; 3000 previously failed patients are still eligible for protease inhibitor therapy, 40% of them already developed cirrhosis stage and 40% are null responders to the previous therapy. As a file is created for treatment authorization, the system counts automatically the Priority Index according to the calculation set in the guideline. Priority Index reflects the urgency of treatment. The most prominent parameter of the Index is the degree of fibrosis, but it also takes into account the progression rate, prognostic factors, and special situations.

Natural history of cirrhosis

Significant strides have been made in the last few years in advancing our knowledge of the natural history of cirrhosis. These include (1) a better understanding of prognosis in compensated and decompensated cirrhosis, (2) improved estimates of the natural course of variceal bleeding in patients receiving standard of care therapy, (3) recognition of renal failure and infection as important determinants of mortality in the clinic course, (4) realization of the importance of hepatic venous pressure gradient as a marker of prognosis, progression, and treatment response, and (5) evolution of noninvasive studies of liver stiffness as potential predictors of decompensation. Further studies identifying cirrhotics at highest risk of transitioning from a compensated state to a decompensated state will be important in order to alter the natural history of cirrhosis.

Natural history of cirrhosis

Significant strides have been made in the last few years in advancing our knowledge of the natural history of cirrhosis. These include (1) a better understanding of prognosis in compensated and decompensated cirrhosis, (2) improved estimates of the natural course of variceal bleeding in patients receiving standard of care therapy, (3) recognition of renal failure and infection as important determinants of mortality in the clinic course, (4) realization of the importance of hepatic venous pressure gradient as a marker of prognosis, progression, and treatment response, and (5) evolution of noninvasive studies of liver stiffness as potential predictors of decompensation. Further studies identifying cirrhotics at highest risk of transitioning from a compensated state to a decompensated state will be important in order to alter the natural history of cirrhosis.

Hepatocellular carcinoma in patients with chronic hepatitis C virus infection in the Asia-Pacific region

Hepatocellular carcinoma (HCC) is the third-leading cause of cancer-related mortality worldwide. Although hepatitis B still remains the most common risk factor worldwide, chronic hepatitis C virus (HCV) infection is the driving force for the increased incidence of HCC especially in Western countries and Japan. In hepatitis B virus (HBV)-endemic areas, after successful vaccination programs against HBV, chronic HCV infection is now emerging as an important cause of chronic liver diseases. Unlike patients with chronic hepatitis B, those with chronic hepatitis C (CHC) develop HCC in the presence of established cirrhosis in most cases. However, a significant minority of CHC develops HCC in the absence of cirrhosis. Although HCV is a RNA virus with little potential for integrating its genetic material into host genome, various HCV proteins, including core, envelope, and nonstructural proteins, have oncogenic properties by inducing oxidative stress, disturbing cellular regulatory pathways associated with proliferation and apoptosis, and suppressing host immune responses. Overall, a combination of virus-specific, host genetic, environmental, and immune-related factors are likely to determine progression to HCC. Strategies aimed at eliminating the virus may provide opportunities for effective prevention of the development of HCC. Pegylated interferon plus ribavirin therapy appears to be effective at reducing the risk of HCC in patients who achieve sustained virologic responses. In summary, with the emerging importance of CHC, mechanisms of HCV-associated hepatocellular carcinogenesis should be clarified to provide insight into advanced therapeutic and preventive approaches, which eventually decrease the incidence and mortality of HCC.

Extracellular matrix transcriptome dynamics in hepatocellular carcinoma

The extracellular matrix undergoes extensive remodeling during hepatocellular carcinoma and functions as a critical component of the tumor microenvironment by providing a substratum for cell adhesion and serving as a reservoir for a variety of cytokines and growth factors. Despite the clinical correlation between ECM deposition and hepatocellular carcinoma progression, it remains unclear how global extracellular matrix gene expression is altered in hepatocellular carcinoma and the molecular pathways that govern this change. Herein, a comprehensive analysis of the extracellular matrix transcriptome using an RNA-sequencing dataset provided by The Cancer Genome Atlas consortium was conducted and indicates substantial differential gene expression of key extracellular matrix collagens, glycoproteins, and proteoglycans in hepatocellular carcinoma. This analysis also reveals alternative expression of extracellular matrix gene transcript variants that could impact biological activity and serves as a framework for exploring the dynamic nature of the extracellular matrix transcriptome in cancer and identifying candidate genes for future exploration.

Liver stiffness measurement as an alternative to fibrotic stage in risk assessment of hepatocellular carcinoma incidence for chronic hepatitis C patients

BACKGROUND

Hepatic fibrosis stage is useful in assessing risk of hepatocellular carcinoma (HCC) occurrence.

AIM

To evaluate liver stiffness measurement (LSM), in addition to fibrosis stage, in risk assessment of long-term HCC occurrence for patients with chronic hepatitis C.

PATIENTS AND METHODS

Consecutive patients with chronic hepatitis C, without past history and presence of HCC, with concomitant liver biopsy and LSM were enrolled in this study. All patients attended regular surveillance for HCC development every 3-12 months. The medical records were reviewed. Follow-up LSM was performed at least 1 year later.

RESULTS

One hundred and ninety-eight patients (M/F: 112/86) with reliable LSM results were enrolled. Ten patients developed HCC in a median follow-up period of 47.8 months. For patients with initial LSM >24 kPa, 12-24 kPa, and <12 kPa, 5- year HCC incidence was 45.1%, 9.5% and 0.9% respectively. Multivariate analysis showed patients with LSM>24 kPa and patients with LSM 12-24 kPa had higher risks of HCC development (HR: 24.6, CI: 2.7-220.4 and HR:11.7, CI:1.3-105.2). Patients without sustained virological response after treatment also had higher risk of HCC occurrence (HR: 9.7, CI: 1.1-82.2). Among 106 patients with follow-up LSM, there was a higher risk of HCC development for patients with LSM>12 kPa in the initial and follow-up LSM.

CONCLUSION

As an alternative of fibrosis stage, initial LSM is useful as a non-invasive method in risk assessment of HCC occurrence for patients with chronic hepatitis C. Serial follow-up LSM>12 kPa carries higher risk of HCC development.

Presence of a hypovascular hepatic nodule showing hypointensity on hepatocyte-phase image is a risk factor for hypervascular hepatocellular carcinoma

PURPOSE

To determine whether the presence of a hypovascular nodule in the liver showing hypointensity on hepatocyte-phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) is a risk factor for hypervascular hepatocellular carcinoma (HCC) in patients with chronic liver disease.

MATERIALS AND METHODS

Forty-one patients with pathologically confirmed hypervascular HCC and 41 age- and gender-matched controls were retrospectively selected. These patients had undergone EOB-MRI at least twice: the latest EOB-MRI and EOB-MRI performed more than 6 months earlier. History of hypervascular HCC, presence of a hypointense hypovascular nodule in previous hepatocyte-phase MR images, percent prothrombin time, platelet count, serum levels of albumin, total bilirubin, aspartate aminotransferase, alanine aminotransferase, α-fetoprotein, and protein induced by vitamin K absence-II (PIVKA-II) were variables evaluated by multivariate logistic regression analysis.

RESULTS

Multivariate analysis revealed that serum albumin level (odds ratio [95% confidence interval], 0.19 [0.06-0.57]; P = 0.0024), history of hypervascular HCC (8.62 [2.71-32.8]; P = 0.0001), and presence of a hypointense hypovascular nodule (4.18 [1.18-17.2]; P = 0.0256) were significant risk factors for hypervascular HCC.

CONCLUSION

Patients with chronic liver disease showing a hypointense hypovascular nodule in the liver on hepatocyte-phase EOB-MRI have a high risk of HCC development.