Magnetic resonance imaging of hepatocellular carcinoma

Non-hypervascular hepatobiliary phase hypointense lesions detected in patients with hepatocellular carcinoma: a post hoc analysis of SORAMIC trial to identify risk factors for progression

OBJECTIVES

To identify clinical and imaging parameters associated with progression of non-hypervascular hepatobiliary phase hypointense lesions during follow-up in patients who received treatment for hepatocellular carcinoma.

METHODS

A total of 67 patients with 106 lesions were identified after screening 538 patients who underwent gadoxetic acid-enhanced MRI within the SORAMIC trial. All patients were allocated to the trial treatment according to the trial scheme, and 61 of 67 patients received systemic treatment with sorafenib (either alone or combined with locoregional therapies) during the trial period. Follow-up images after treatment according to trial scheme were reviewed for subsequent hypervascularization or > 1 cm size increase. The correlation between progression and several imaging and clinical parameters was assessed using univariable and multivariable analyses.

RESULTS

On a median 178 (range, 48-1072) days follow-up period, progression was encountered in 18 (16.9%) lesions in 12 (17.9%) patients. In univariable analysis size > 12.6 mm (p = 0.070), ECOG-PS (p = 0.025), hypointensity at T1-weighted imaging (p = 0.028), hyperintensity at T2-weighted imaging (p < 0.001), hyperintensity at DWI images (p = 0.007), and cirrhosis (p = 0.065) were correlated with progression during follow-up. Hyperintensity at T2 images (p = 0.011) was an independent risk factor for progression in multivariable analysis, as well as cirrhosis (p = 0.033) and ECOG-PS (p = 0.030).

CONCLUSIONS

Non-hypervascular hepatobiliary phase hypointense lesions are associated with subsequent progression after treatment in patients with HCC. T2 hyperintensity, diffusion restriction, cirrhosis, and higher ECOG-PS could identify lesions with increased risk. These factors should be considered for further diagnostic evaluation or treatment of such lesions.

KEY POINTS

• Non-hypervascular hepatobiliary phase hypointense lesions have considerable risk of progression in patients with hepatocellular carcinoma receiving treatment. • T2 hyperintensity, cirrhosis, ECOG-PS, and hyperintensity at DWI are associated with increased risk of progression. • Non-hypervascular hepatobiliary phase hypointense lesions should be considered in the decision-making process of locoregional therapies, especially in the presence of these risk factors.

[Radiologic Diagnosis of Hepatocellular Carcinoma]

There are various causes of hepatocellular carcinoma, including viral hepatitis, and treatment strategies are often established based on the radiology diagnosis, unlike other carcinomas. The liver imaging reporting and data system (LI-RADS) is a diagnostic system developed by the American College of Radiologists for clear communication and standardized reports of the liver imaging findings. It was recently included in the clinical guidance of the American Association for the Study of Liver Diseases. In addition, the radiologic findings of hepatocellular carcinoma (HCC) enable a prediction of the prognosis after treatment and a diagnosis of diseases because the use of gadoxetic acid MRI has become more common. Thus, the role of radiology for the diagnosis and treatment of HCC is expected to be developed further.

Hepatocellular carcinoma as a complication of Niemann-Pick disease type C1

Niemann-Pick disease type C (NPC) is a rare and fatal lysosomal storage disorder characterized by neurodegeneration and hepatic involvement. Mutations in either NPC1 or NPC2, two genes encoding lysosomal proteins, lead to an intracellular accumulation of unesterified cholesterol and sphingolipids in late endosomes/lysosomes. Early cholestatic disease is considered a hallmark of patients with early disease onset. This can potentially result in liver failure shortly after birth or subclinical hepatic inflammation. Previous reports suggest an association between NPC and hepatocellular carcinoma, a cancer that is rare during childhood. We present a 12-year-old male with a known diagnosis of NPC1 disease who was found to have a stage III hepatocellular carcinoma, underwent surgical resection with adjuvant chemotherapy, and subsequently died from metastatic disease. This report provides evidence of an increased risk of hepatocellular carcinoma in NPC patients, suggesting a need for screening in this patient population.

Atrial cholangiocarcinoma diagnosed by cardiac magnetic resonance imaging

In this rare case of intrahepatic cholangiocarcinoma (ICC) tumor thrombus with right atrial (RA) invasion, we describe its diagnostic workup based on cardiac magnetic resonance imaging (cMRI). An 85-year-old man underwent transthoracic echocardiography due to dyspnea, revealing a RA mass. Comprehensive cMRI evaluation, including cine bright blood, T1- and T2-weighed, fat-suppressed, and contrast-enhanced imaging, was performed and diagnosis of ICC tumor thrombus with RA invasion was made. This first description of cMRI-guided diagnosis of RA invasion by ICC tumor thrombus points out the usefulness of cMRI for the diagnostic approach of RA masses suggestive of tumor thrombus.

[State of the art in the diagnostics of hepatocellular carcinoma and current treatment options]

Hepatocellular carcinoma (HCC) is the most frequent primary hepatic malignancy and arises most often based on liver cirrhosis. Of the HCC 80-85% demonstrate a typical contrast medium behavior in imaging, characterized by arterial hypervascularization followed by wash-out in the portal or late venous phase. This specific contrast behavior is diagnostic for HCC in patients at risk. The use of liver-specific contrast agents increases the sensitivity for diagnosis of HCC and can facilitate the differentiation from other liver lesions. At initial diagnosis approximately 50% of HCC are solitary, 40% multifocal and 10% diffuse. Depending on the tumor extent and stage, therapeutic options in patients with HCC include local treatment (resection, ablation, radiation, liver transplantation), locoregional measures (transarterial chemoembolization, selective internal radiotherapy) or systemic therapy (including immunotherapy), either as a stand-alone procedure or in various combinations.

Pediatric Liver Tumors

Although liver tumors are rare in the pediatric population, they are common in the setting of children with specific risk factors requiring increased awareness and, in some instances, screening. The evaluation of a liver mass in children is largely driven by the age at diagnosis, the presence of any medical comorbidities, and initial testing with alpha fetoprotein and imaging. Specific guidelines for the management of different tumors have been implemented in recent years such that a multidisciplinary approach is ideal and care should be provided by centers with experience in their management.

MicroRNA-1277 Inhibits Proliferation and Migration of Hepatocellular Carcinoma HepG2 Cells by Targeting and Suppressing BMP4 Expression and Reflects the Significant Indicative Role in Hepatocellular Carcinoma Pathology and Diagnosis After Magnetic Resonance Imaging Assessment

Our study aimed to investigate the roles and possible regulatory mechanism of miR-1277 in the development of hepatocellular carcinoma (HCC). HCC patients were identified from patients who were diagnosed with focal liver lesions using magnetic resonance imaging (MRI). The expression levels of miR-1277 in the serum of HCC patients and HepG2 cells were measured. Then miR-1277 mimic, miR-1277 inhibitor, or scramble RNA was transfected into HepG2 cells. The effects of miR-1277 overexpression and suppression on HepG2 cell proliferation, migration, and invasion were then investigated. Additionally, the expression levels of epithelial–mesenchymal transition (EMT)-related markers, including E-cadherin, β-catenin, and vimentin, were detected. Target prediction and luciferase reporter assay were performed to explore the potential target of miR-1277. miR-1277 was significantly downregulated in the serum of HCC patients and HepG2 cells. Suppression of miR-1277 promoted HepG2 cell proliferation, migration, and invasion, whereas overexpression of miR-1277 had opposite effects. In addition, after miR-1277 was suppressed, the expressions of E-cadherin and β-catenin were significantly increased, while the expressions of vimentin were markedly decreased. Bone morphogenetic protein 4 (BMP4) was identified as the direct target of miR-1277. Knockdown of BMP4 reversed the effects of miR-1277 suppression on HepG2 cell migration and invasion, as well as the expressions of E-cadherin, β-catenin, and vimentin. Our results indicate that downregulation of miR-1277 may promote the migration and invasion of HepG2 cells by targeting BMP4 to induce EMT. Combination of MRI and miR-1277 level will facilitate the diagnosis and treatment of HCC.

Non-invasive detection of liver fibrosis: MR imaging features vs. MR elastography

PURPOSE

To compare accuracy of morphological features of liver on MRI and liver stiffness with MR elastography (MRE) for detection of significant liver fibrosis and cirrhosis.

MATERIALS AND METHODS

In this retrospective study, we evaluated 62 patients who underwent liver MRI with MRE and histological confirmation of liver fibrosis within 6 months. Two radiologists, blinded to histology results, independently evaluated liver parenchyma texture, surface nodularity, signs of volumetric changes, and portal hypertension for presence of significant fibrosis and cirrhosis. Two more readers independently calculated mean liver stiffness values with MRE. Interobserver agreement was evaluated with kappa and intra-class correlation coefficient (ICC) analysis. Diagnostic accuracy was assessed with area under receiver operating characteristic (AUROC) analysis. Comparison of AUROCs of MRI and MRE was performed.

RESULTS

Liver fibrosis was present in 37 patients. The interobserver agreement was poor to good (κ = 0.12-0.74) for MRI features and excellent for MRE (ICC 0.97, 95% CI 0.95-0.98). MRI features had 48.5%-87.9% sensitivity, 55.2%-100% specificity, and 71.5%-81.6% accuracy/for detection of significant fibrosis. MRE performed better with 100% sensitivity, 96.5% specificity, and 98.9% accuracy. For the detection of cirrhosis, MRE performed better than MRI features with 88.2% sensitivity (vs. 41.2%-82.3%), 91.1% specificity (vs. 64.4%-95.6%), and 93.5% accuracy (vs. 60.6%-80.5%). Among the MRI features, surface nodularity and overall impression had the best accuracies of 80.3% and 81.6% for detection of significant fibrosis, respectively. For cirrhosis, parenchyma texture and overall impression had the best accuracies of 80.5% and 79.7%, respectively. Overall, MRE had significantly greater AUROC than MRI features for detection of both significant fibrosis (0.98.9 vs 0.71-0.82, P < 0.001) and cirrhosis (0.93.5 vs. 0.61-0.80.5, P < 0.01).

CONCLUSION

MRE is superior to MRI for the non-invasive diagnosis of significant liver fibrosis and cirrhosis.

DCE-MRI of hepatocellular carcinoma: perfusion quantification with Tofts model versus shutter-speed model--initial experience

OBJECTIVE

To quantify hepatocellular carcinoma (HCC) perfusion and flow with the fast exchange regime-allowed Shutter-Speed model (SSM) compared to the Tofts model (TM).

MATERIALS AND METHODS

In this prospective study, 25 patients with HCC underwent DCE-MRI. ROIs were placed in liver parenchyma, portal vein, aorta and HCC lesions. Signal intensities were analyzed employing dual-input TM and SSM models. ART (arterial fraction), K (trans) (contrast agent transfer rate constant from plasma to extravascular extracellular space), ve (extravascular extracellular volume fraction), kep (contrast agent intravasation rate constant), and τi (mean intracellular water molecule lifetime) were compared between liver parenchyma and HCC, and ART, K (trans), v e and k ep were compared between models using Wilcoxon tests and limits of agreement. Test-retest reproducibility was assessed in 10 patients.

RESULTS

ART and v e obtained with TM; ART, ve, ke and τi obtained with SSM were significantly different between liver parenchyma and HCC (p < 0.04). Parameters showed variable reproducibility (CV range 14.7-66.5% for both models). Liver K (trans) and ve; HCC ve and kep were significantly different when estimated with the two models (p < 0.03).

CONCLUSION

Our results show differences when computed between the TM and the SSM. However, these differences are smaller than parameter reproducibilities and may be of limited clinical significance.

X-ray Scatter Imaging of Hepatocellular Carcinoma in a Mouse Model Using Nanoparticle Contrast Agents

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and is almost uniformly fatal. Current methods of detection include ultrasound examination and imaging by CT scan or MRI; however, these techniques are problematic in terms of sensitivity and specificity, and the detection of early tumors (<1 cm diameter) has proven elusive. Better, more specific, and more sensitive detection methods are therefore urgently needed. Here we discuss the application of a newly developed x-ray imaging technique called Spatial Frequency Heterodyne Imaging (SFHI) for the early detection of HCC. SFHI uses x-rays scattered by an object to form an image and is more sensitive than conventional absorption-based x-radiography. We show that tissues labeled in vivo with gold nanoparticle contrast agents can be detected using SFHI. We also demonstrate that directed targeting and SFHI of HCC tumors in a mouse model is possible through the use of HCC-specific antibodies. The enhanced sensitivity of SFHI relative to currently available techniques enables the x-ray imaging of tumors that are just a few millimeters in diameter and substantially reduces the amount of nanoparticle contrast agent required for intravenous injection relative to absorption-based x-ray imaging.

Hepatocellular carcinoma in children

Liver tumors are relatively rare in childhood, but may be associated with a range of diagnostic, genetic, therapeutic, and surgical challenges sufficient to tax even the most experienced clinician. This article outlines the epidemiology, etiology, pathologic condition, initial workup, and management of hepatocellular carcinoma in children and adolescents.

Role of portal vein tumor thrombosis in quantitative perfusion analysis of contrast-enhanced ultrasound of hepatocellular carcinoma

The goal of our study was to evaluate the differences between quantitative parameters of hepatocellular carcinoma (HCC) with or without portal vein tumor thrombosis (PVTT) on contrast-enhanced ultrasound (CEUS). Twenty-four patients with HCC with PVTT and 48 without PVTT underwent CEUS using sulfur hexafluoride microbubbles. Dynamic images were analyzed with quantification software. Time-intensity curves were obtained for HCC and surrounding liver parenchyma, and parameters including the intensity maximum (IMAX), rising time (RT), mean transit time and time to peak (TTP) were compared within and between the PVTT and control groups, respectively. RT and TTP of HCC were significantly faster than those of surrounding liver parenchyma in both the PVTT and control groups. IMAX of HCC was significantly stronger than that of surrounding liver in the control group, but not significantly different from that of liver parenchyma in the PVTT group. RT and TTP of HCC and surrounding liver were significantly faster in the PVTT group compared with the control group, whereas IMAX values of HCC in the PVTT group were lower than those in the control group. HCC with PVTT presents different hemodynamic parameters, with faster RT and TTP and lower IMAX than those for HCC without PVTT. Quantitative perfusion analysis of CEUS may be a potential method for predicting PVTT.

Utility of adding Primovist magnetic resonance imaging to analysis of hepatocellular carcinoma by liver dynamic computed tomography

BACKGROUND & AIMS

More information is needed on use of Primovist-enhanced magnetic resonance imaging (MRI) during initial staging analysis of patients with hepatocellular carcinoma (HCC) who are candidates for treatment with liver dynamic computed tomography (CT).

METHODS

We studied 104 patients who were initially diagnosed as Barcelona Clinic Liver Cancer (BCLC) stage 0 or A, without any other suspicious intrahepatic lesions, by liver dynamic CT from December 2009 to May 2012 at Inha University Hospital in Korea. We evaluated whether an addition of Primovist-enhanced MRI examination affected determination of BCLC stage, compared with liver dynamic CT.

RESULTS

On the basis of CT analysis, the median tumor size was 2.3 cm, and 98 patients had HCCs that met the Milan criteria (94.2%). All 104 patients (100%) had nodular type HCC. Abnormal intrahepatic findings were detected by Primovist-enhanced MRI in 41 patients (39.4%). Eighteen patients (17.3%) had new HCCs, but 6 patients who were initially of BCLC stage A remained at this stage, despite increases in tumor numbers. Of the 104 patients, 31 (29.8%) and 73 (70.2%) had BCLC stage 0 and A HCC before Primovist-enhanced MRI, respectively, and 26 (25.0%), 71 (68.3%), and 7 (6.7%) patients had BCLC stages 0, A, and B HCC after Primovist-enhanced MRI, respectively. In 12 of the 104 patients (11.5%), BCLC stage changed from 0 to A (5/31, 16.1%) or from A to B (7/73, 9.6%).

CONCLUSIONS

Primovist-enhanced MRI can provide additional information that can lead to the detection of new intrahepatic HCC lesions during initial staging analyses of patients with BCLC stage 0 or A HCC by liver dynamic CT, despite the absence of other suspicious liver lesions.

Heterogeneous staining in the liver parenchyma after the injection of perflubutane microbubble contrast agent

This study aimed to characterize the features of heterogeneous staining in the liver after injection of perflubutane microbubble agent (Sonazoid(TM), 0.0075 mL/kg). Digitized hepatic contrast sonograms from 906 subjects were reviewed to assess time-related changes in heterogeneous staining and the possible association between this effect and the clinical backgrounds was analyzed. Heterogeneous staining was found in seven subjects (0.77%) on 15-min phase sonograms. The staining initially appeared as hyper-enhanced circular spots in the liver 10 min or later after the agent injection. The number of spots increased gradually with unequally-spaced distribution. Although the staining pattern did not improve during the examination, there were no abnormal findings in vital signs or symptoms on the day and blood test results or sonograms on the following day. Heterogeneous staining is a side effect that impedes ultrasound examination. However, at present, the precise causes and underlying mechanisms of this event are unknown.

MR elastography of liver tumours: value of viscoelastic properties for tumour characterisation

OBJECTIVES

To assess the value of the viscoelastic parameters in the characterisation of liver tumours at MR elastography.

PATIENTS AND METHODS

Ninety-four patients with liver tumours >1 cm prospectively underwent MR elastography using 50-Hz mechanical waves and a full three-directional motion-sensitive sequence. The model-free viscoelastic parameters (the complex shear modulus and its real and imaginary parts, i.e. the storage and loss moduli) were calculated in 72 lesions after exclusion of cystic, treated or histopathologically undetermined tumours.

RESULTS

We observed higher absolute shear modulus and loss modulus in malignant versus benign tumours (3.38 ± 0.26 versus 2.41 ± 0.15 kPa, P < 0.01 and 2.25 ± 0.26 versus 1.05 ± 0.13 kPa, P < 0.001, respectively). Moreover, the loss modulus of hepatocellular carcinomas was significantly higher than in benign hepatocellular tumours. The storage modulus did not differ significantly between malignant and benign tumours. The area under the receiver-operating characteristic curve of loss modulus was significantly larger than that of the absolute shear modulus and storage modulus when comparing malignant and benign lesions.

CONCLUSIONS

The increased loss modulus is a better discriminator between benign and malignant tumours than the increased storage modulus or absolute value of the shear modulus.

KEY POINTS

• Magnetic Resonance elastography is a new method of assessing the liver. • Increased loss modulus is an indicator of malignancy in hepatic tumours. • Loss modulus is a better discriminator than absolute shear modulus values. • The viscoelastic properties of lesions offer promise for characterising liver tumours.

Hepatocellular carcinoma: management of an increasingly common problem

Hepatocellular carcinoma (HCC) is a common cancer that typically occurs in the setting of cirrhosis and chronic hepatitis virus infections. Hepatitis B and C account for approximately 80% of cases worldwide. HCC is currently the fifth most common malignancy in men and the eighth in women worldwide; its incidence is increasing dramatically in many parts of the world. Recognition of those at risk and early diagnosis by surveillance with imaging, with or without serologic testing, are extremely important. Many highly effective and even curative therapies are now available and include resection, liver transplantation, and local ablation. Appropriate application of these interventions offers hope of prolonged survival to many patients with this otherwise lethal complication of liver disease.

Acute heart failure caused by a giant hepatocellular metastatic tumor of the right atrium

We present a symptomatic 40-year-old cirrhotic man who presented with sudden onsets of syncope. Echocardiography revealed right ventricular outflow track obstruction caused by a huge right atrial mass. The tumor was surgically excised under cardiopulmonary bypass. Although no primary cancerous lesion in the liver was detected, histopathology revealed that the mass was a metastatic hepatocellular carcinoma. The aim of this report is to show the value of urgent preoperative computed tomography and its contribution in the operative strategy. The importance of urgent surgical treatment with tricuspid valve sparing tumor resection is emphasized even though the prognosis for such patients is dismal. We also discuss the further management options of such rare cases

[Malignant focal liver lesions]

Focal liver lesions are a very common occurrence. The detection and differentiation of such lesions is particularly important for the management of oncology patients and is a core task for radiology. The early and conclusive detection of malignant liver processes in a cost-efficient manner and with a low radiation dose for the patient requires systematic and skillful use of the various radiological methods. This review explains the application of current radiological methods for the detection and differentiation of malignant liver lesions and the typical appearance of the most commonly found liver malignancies.

MR imaging of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignancy typically associated with chronic liver disease and is a leading cause of mortality among these patients. Prognosis is improved when detected early. MRI is the best imaging examination for accurate diagnosis. Although arterial enhancement with delayed washout, increased T2-weighted signal intensity, delayed capsular enhancement, restricted diffusion, and tumor thrombus are typical features, not all lesions demonstrate these findings. The radiologist must be familiar with these typical imaging characteristics, and less common appearances and associated findings of HCC, and must be able to differentiate them from those of lesions that mimic HCC. Knowledge of therapeutic options and how those are related to imaging findings is imperative to assist clinicians in managing these patients.

Value of diffusion-weighted magnetic resonance images for discrimination of focal benign and malignant hepatic lesions: a meta-analysis

PURPOSE

To evaluate the ability of DW-MRI in differentiating malignant hepatic tumors from benign lesions.

MATERIALS AND METHODS

Meta-analysis of 14 diagnostic studies was used. A systematic search in Medline, Embase, Web of Science (from January, 1966, to October, 2009), and Cochrane Controlled Clinical Trials Register Database (through third Quarter 2009) was used with screening of the literature.

RESULTS

A meta-analysis of all 95 published studies was performed. Fourteen studies fulfilled the inclusion criteria (804 patients with 1665 hepatic lesions). The global sensitivity was 0.91 (95% confidence interval [CI], 0.86-0.94), the specificity was 0.93 (95% CI, 0.86-0.97), the positive likelihood ratio (PLR) was 13.10 (95% CI, 6.30-27.26), the negative likelihood ratio (NLR) was 0.10 (95% CI, 0.06-0.15), and the diagnostic odds ratio (DOR) was 133.76 (95% CI, 49.77-359.45). The area under the curve of the summary receiver operator characteristic (SROC) was 0.96 (95% CI 0.94-0.98).

CONCLUSION

Diffusion-weighted magnetic resonance imaging is potential technically feasible to differentiate malignant from benign focal liver lesions. Apparent diffusion coefficient measurements can be useful in providing rapid quantifiable information.

Quantitative multiparametric PROPELLER MRI of diethylnitrosamine-induced hepatocarcinogenesis in wister rat model

PURPOSE

To develop a quantitative multiparametric PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) magnetic resonance imaging (MRI) approach and its application in a diethylnitrosamine (DEN) chemically induced rodent model of hepatocarcinogenesis for lesion characterization.

MATERIALS AND METHODS

In nine rats with 33 cirrhosis-associated hepatic nodules including regenerative nodule (RN), dysplastic nodule (DN), hepatocellular carcinoma (HCC), and cyst, multiparametric PROPELLER MRI (diffusion-weighted, T2/M0 (proton density) mapping and T1-weighted) were performed. Apparent diffusion coefficient (ADC) maps, T2 and M0 maps of each tumor were generated. We compared ADC, T2, and M0 measurements for each type of hepatic nodule, confirmed at histopathology.

RESULTS

PROPELLER images and resultant parametric maps were inherently coregistered without image distortion or motion artifacts. All types of hepatic nodules demonstrated complex imaging characteristics within conventional T1- and T2-weighted images. Quantitatively, cysts were distinguished from RN, DN, and HCC with significantly higher ADC and T2; however, there was no significant difference of ADC and T2 between HCC, DN, and RN. Mean tumor M0 values of HCC were significantly higher than those of DN, RN, and cysts.

CONCLUSION

This study exploited quantitative PROPELLER MRI and multidimensional analysis approaches in an attempt to differentiate hepatic nodules in the DEN rodent model of hepatocarcinogenesis. This method offers great potential for parallel parameterization during noninvasive interrogation of hepatic tissue properties.

Macrophage migration inhibitory factor plays a pivotal role in hepatocellular carcinoma and may be a noninvasive imaging target

Macrophage migration inhibitory factor (MIF) has emerged to play a central role in the control of the host inflammatory and immune response. Several reports have documented that MIF can inactivate the tumor suppresser activity of p53; overexpression of MIF was significantly higher in both the sera and the local lesions from patients with HCC than from patients with normal controls. These findings indicate that MIF may contribute to multiple aspects of tumor progression and neoplasia, thus MIF may be an effective therapeutic target molecule. We speculate that MIF is important for the development and progression of hepatocellular carcinoma, and can be used as a marker for tumor detection.

Gadoxetate disodium-enhanced MRI of the liver: part 2, protocol optimization and lesion appearance in the cirrhotic liver

OBJECTIVE

The purpose of this article is to review the use of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (gadoxetate disodium [Gd-EOB-DTPA]) in the cirrhotic liver and illustrate the imaging appearance of lesions commonly encountered in the cirrhotic liver.

CONCLUSION

Gd-EOB-DTPA shows promise as a problem-solving tool in the cirrhotic liver because it provides additional information that may be helpful in lesion detection and characterization. Further research is needed to optimize Gd-EOB-DTPA imaging protocols in cirrhosis and develop diagnostic criteria for liver lesions in the cirrhotic liver.

Diffusion-weighted MRI provides additional value to conventional dynamic contrast-enhanced MRI for detection of hepatocellular carcinoma

The purpose of this study was to evaluate the accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) in differentiating HCC from benign cirrhotic lesions compared with conventional dynamic contrast-enhanced MRI. Fifty-five patients with cirrhosis underwent conventional and DW-MRI at 1.5 Tesla. Signal intensity ratios (SI(ratio)) of solid liver lesions to adjacent hepatic parenchyma were measured for b0, b100, b600 and b1000, and the apparent diffusion coefficients (ADC) were calculated. In 27 patients, imaging results were compared to histopathology, and in 28 patients, to imaging follow-up. Based on predetermined thresholds, sensitivity and specificity of DW-MRI and conventional MRI were compared. SI(ratio) was significantly different between malignant and benign lesions at all b-values (P < 0.0001). No significant difference in ADC was seen (P = 0.47). For detection of malignant lesions, DW-MRI with b600-SI(ratio) yielded a sensitivity of 95.2% compared to 80.6% for conventional MRI (P = 0.023) and a specificity of 82.7% compared to 65.4% (P = 0.064). The improved accuracy was most beneficial for differentiating malignant lesions smaller than 2 cm. DW-MRI with b600-SI(ratio) improved the detection of small HCC and the differentiation of pseudotumoral lesions compared with conventional MRI.

MR Imaging of hepatocellular carcinoma in the cirrhotic liver: challenges and controversies

The incidence of hepatocellular carcinoma (HCC) is expected to increase in the next 2 decades, largely due to hepatitis C infection and secondary cirrhosis. HCC is being detected at an earlier stage owing to the implementation of screening programs. Biopsy is no longer required prior to treatment, and diagnosis of HCC is heavily dependent on imaging characteristics. The most recent recommendations by the American Association for the Study of Liver Diseases (AASLD) state that a diagnosis of HCC can be made if a mass larger than 2 cm shows typical features of HCC (hypervascularity in the arterial phase and washout in the venous phase) at contrast material-enhanced computed tomography or magnetic resonance (MR) imaging or if a mass measuring 1-2 cm shows these features at both modalities. There is an ever-increasing demand on radiologists to detect smaller tumors, when curative therapies are most effective. However, the major difficulty in imaging cirrhosis is the characterization of hypervascular nodules smaller than 2 cm, which often have nonspecific imaging characteristics. The authors present a review of the MR imaging and pathologic features of regenerative nodules and dysplastic nodules and focus on HCC in the cirrhotic liver, with particular reference to small tumors and lesions that may mimic HCC. The authors also review the sensitivity of MR imaging for the detection of these tumors and discuss the staging of HCC and the treatment options in the context of the guidelines of the AASLD and the imaging criteria required by the United Network for Organ Sharing for transplantation. MR findings following ablation and chemoembolization are also reviewed.

Surveillance of cirrhosis for hepatocellular carcinoma: a cost-utility analysis

Using a decision-analytic model, we evaluated the effectiveness and cost-effectiveness of surveillance for hepatocellular carcinoma (HCC) in individuals with cirrhosis. Separate cohorts with cirrhosis due to alcoholic liver disease, hepatitis B and hepatitis C were simulated. Results were also combined to approximate a mixed aetiology population. Comparisons were made between a variety of surveillance algorithms using α-foetoprotein (AFP) assay and/or ultrasound at 6- and 12-monthly intervals. Parameter estimates were obtained from comprehensive literature reviews. Uncertainty was explored using one-way and probabilistic sensitivity analyses. In the mixed aetiology cohort, 6-monthly AFP+ultrasound was predicted to be the most effective strategy. The model estimates that, compared with no surveillance, this strategy may triple the number of people with operable tumours at diagnosis and almost halve the number of people who die from HCC. The cheapest strategy employed triage with annual AFP (incremental cost-effectiveness ratio (ICER): £20 700 per quality-adjusted life-year (QALY) gained). At a willingness-to-pay threshold of £30 000 per QALY the most cost-effective strategy used triage with 6-monthly AFP (ICER: £27 600 per QALY gained). The addition of ultrasound to this strategy increased the ICER to £60 100 per QALY gained. Surveillance appears most cost-effective in individuals with hepatitis B-related cirrhosis, potentially due to younger age at diagnosis of cirrhosis. Our results suggest that, in a UK NHS context, surveillance of individuals with cirrhosis for HCC should be considered effective and cost-effective. The economic efficiency of different surveillance strategies is predicted to vary markedly according to cirrhosis aetiology.

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

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

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

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

A new prognostic system for hepatocellular carcinoma including recurrent cases: a study of 861 patients in a single institution

OBJECTIVE

To manage hepatocellular carcinoma (HCC) patients surviving for a long term, the treatment strategy for recurrent cancer is as important as that for the initial treatment. However, no prognostic scoring system has been available for patients with HCC recurrence. The purpose of this study was to develop a new staging system for deciding the treatment strategy not only for first-time diagnosed patients but also for recurrent patients.

METHODS

A total of 861 cases diagnosed at our single institution from 1993 to 2003 were included. Overall survival was the only end point. The Cox model was used for multivariate analyses.

RESULTS

As of August 2004, 344 cases (59%) had died. Overall median survival time was 41 months. For multivariate Cox regression analysis, independent predictive factors of survival were the number of recurrences, the Child-Pugh score, 3 nodules less than 3 cm and none of vascular invasion, and the alpha-fetoprotein level. A simple scoring system was thus developed, assigning scores (0/1) to the 4 covariates of the final model. Compared with the other scoring systems, the new scoring system has a greater discriminant ability.

CONCLUSIONS

We concluded that our scoring system can serve as a new prognostic system that reflects the spread of HCC, treatment response, and liver function. It should be very useful as the only method which can be applied for patients with recurrence.

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

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

Magnetic resonance imaging of liver malignancies

The histological structure of the liver is complex, consisting of hepatocytes, biliary epithelium, and mesenchymal cells. From this large variety of cells, a broad spectrum of benign and malignant liver lesions in originate. An accurate diagnosis of these lesions is mandatory for choosing an appropriate therapeutic approach. With the recent developments in hardware and software, magnetic resonance imaging (MRI) has emerged as the method of choice in the diagnostic workup of focal liver lesions, in particular in the pretherapeutic stage. The introduction of high-field MRI at 3.0 T in the routine workup and the selective use of liver-specific contrast agents, including hepatobiliary and reticuloendothelial agents, have also strengthened the role of MRI in liver imaging. In this overview article, we will review the recent developments in 3.0-T MRI and MRI contrast agents in the diagnostic workup of the most common malignant liver tumors.

Alpha fetoprotein, ultrasound, computerized tomography and magnetic resonance imaging for detection of hepatocellular carcinoma in patients with advanced cirrhosis

BACKGROUND

Serum alpha fetoprotein (AFP), ultrasound, computerized tomography scanning, and magnetic resonance imaging are commonly used to screen for hepatocellular carcinoma (HCC) in patients with cirrhosis.

AIM

To assess the accuracy of screening in advanced cirrhosis.

METHODS

The study group consisted of 239 patients with proven HCC in the explanted liver at the time of liver transplant. AFP and imaging were done at referral and serially until transplant.

RESULTS

Hepatocellular carcinoma was detected before liver transplant in 78% and discovered incidentally in 22%. The cause of cirrhosis was hepatitis C (HCV) (55%), hepatitis B (HBV) (17%), alcohol (9%), and other/unknown (19%). Although AFP was elevated 62%, the median level was 15 ng/mL. Only 26%, 15% and 13% were more than 100, 400 and 1000 ng/mL, respectively. By comparison, AFP was elevated in 20% without HCC, but exceeded 100 ng/mL in only 3%. The overall accuracy of AFP was poor regardless of the cutoff. Magnetic resonance imaging was more accurate than computerized tomography or ultrasound in detecting tumour, particularly when performed within 3 months of transplant.

CONCLUSIONS

Magnetic resonance imaging is most sensitive for imaging HCC and best reflects actual tumour size. AFP is insensitive and adds little to screening strategies, but has prognostic value when extremely elevated.

[Imaging nodules within cirrhotic liver: how do I do it?]

Cirrhosis is a chronic liver disease characterized by the presence of diffuse parenchymal necrosis, reactive fibrosis and nodular regeneration. These regenerative nodules may evolve into dysplastic nodules and finally nodules of hepatocellular carcinoma (HCC). Improved survival of cirrhotic patients with HCC depends on eligibility to liver transplantation. The purpose of this paper is to review the imaging features of liver nodules within cirrhotic liver and to propose the imaging strategies when considering the possibility of liver transplantation.

Recent advances in the diagnosis of hepatocellular carcinoma

In the last decade, new imaging techniques have become available, offering the possibility of investigating contrast perfusion of liver nodules in cirrhosis. It is now accepted that a non-invasive diagnosis of hepatocellular carcinoma (HCC) can be established based on the vascular pattern, obtained with pure blood pool contrast agents. The diagnostic pattern includes: hypervascularity in the arterial phase (15-35 s after contrast injection), consisting in a contrast signal in the nodule greater than in the surrounding parenchyma, followed by contrast wash out, which leads the nodule to show the same, or, more specifically, a lower contrast signal, than the surrounding parenchyma in the portal and late phases (>40 s after injection). Such a pattern can be obtained not only by computed tomography or magnetic resonance imaging, but also by contrast-enhanced ultrasonography, most simply with real-time low mechanical index harmonic imaging ultrasound equipment with second-generation ultrasound contrast agents. The risk of false-positive diagnosis of malignancy isnearly abolished when the functional vascular pattern is not the only feature, but is superimposed on a nodule visible also without contrast. One single contrast imaging technique may suffice to make a diagnosis of HCC if the nodule is >1 cm in diameter and has developed during a surveillance program. Other types of contrast agents, such as those taken up by the reticular-endothelial system cells, may offer additional diagnostic clues, but definitive evidence of their efficacy is still to be produced. In conclusion, contrast-enhanced imaging techniques now offer the possibility of a non-invasive diagnosis of HCC in a large number of cases, reducing the need of invasive investigations, such as ultrasound-guided biopsy or angiography.

Compensated hepatitis C: unenhanced MR imaging correlated with pathologic grading and staging

BACKGROUND

We prospectively examined unenhanced MR imaging findings in relation to pathologic fibrosis, inflammation and steatosis in patients with compensated chronic hepatitis C viral infection (HCV).

METHODS

Unenhanced MRI at 1.5 T was obtained within one month of core liver biopsy in 64 consecutive candidates for antiviral therapy for compensated HCV. Two pathologists independently graded inflammatory activity index (HAI) and steatosis, and staged fibrosis (grades 0-6). Morphologic MRI findings of cirrhosis, periportal lymph nodes, and MR fat signal ratio from dual gradient echo images were assessed independently by two radiologists blinded to clinical data. MRI and laboratory liver function results were correlated with pathologic results, using Spearman correlation coefficient and stepwise multiple regression.

RESULTS

MR fat signal ratio correlation coefficient with pathologic steatosis was 0.71 (p < 0.0001). Coefficients with fibrosis stage were highest for surface nodularity (r (s) = 47, p < 0.0001) and expanded gallbladder fossa (r (s) = 0.42, p = 0.0006). Coefficients with HAI were highest for lymph node size (r (s) = 0.355, p = 0.0040), surface nodularity (r = 0.47, p < 0.0001), expanded gallbladder fossa (r = 0.332, p = 0.0073), and caudate/right lobe ratio (r = 0.326, p = 0.0110). Combined lab and MRI variables provided the best prediction of fibrosis stage (r (2) = 0.656) and HAI (r (2) = 0.597).

CONCLUSIONS

A combination of MRI and laboratory findings was most predictive of fibrosis and inflammation.

Clinical safety and diagnostic value of the gadolinium chelate gadoterate meglumine (Gd-DOTA)

OBJECTIVE

The purpose of this study was to assess the diagnostic value and safety of the contrast agent gadoterate meglumine (Gd-DOTA, DOTAREM, Guerbet, Roissy CdG Cedex, France) in the setting of a postmarketing surveillance study.

MATERIALS AND METHODS

Between January 2004 and October 2005, radiologists in 61 radiologic institutions were asked to document the routine use of Gd-DOTA in a questionnaire. In addition to assessing the image quality and diagnostic value of the contrast-enhanced magnetic resonance imaging scans, we statistically evaluated and analyzed demographic and safety data.

RESULTS

A total of 24,308 patients were intravenously injected with Gd-DOTA for various diagnostic examinations. The examination allowed for establishing a diagnosis in >99% of cases and image quality was rated as "excellent" or "good" in 97.5% of all cases. Adverse events were noted in only 0.4% of the examinations and were mostly rated as minor, such as feeling of warmth or taste alteration. There was one serious adverse event, albeit with complete recovery.

CONCLUSION

This postmarketing surveillance study suggests diagnostic efficacy and a favorable clinical safety profile of Gd-DOTA in clinical practice.

Hepatocellular carcinoma in patients with nonalcoholic fatty liver disease: helical CT and MR imaging findings with clinical-pathologic comparison

PURPOSE

To retrospectively evaluate the clinical, pathologic, and helical computed tomographic (CT) and magnetic resonance (MR) imaging findings of hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

Institutional review board approval was obtained for this study; the need for patient informed consent was waived. Clinical, pathologic, and imaging findings were retrospectively evaluated in 22 men (mean age, 64.5 years) with HCC and NAFLD. Helical CT and MR images were reviewed for morphologic features such as tumor size, margins, necrosis, and degree of enhancement.

RESULTS

Obesity, diabetes, and hypertension were common findings and were observed in 12 (55%), 14 (64%), and 13 (59%) of the 22 patients, respectively. The serum alpha-fetoprotein level was elevated in eight patients (36%). All patients had pathologic evidence of NAFLD. HCC was well-differentiated in seven patients, moderately differentiated in 11, and poorly differentiated in four. Large tumors (mean diameter, 8.4 cm) were depicted at CT and/or MR imaging in all patients. Twenty-one patients had a solitary or dominant mass. At imaging, tumor margins were well defined in 17 patients, with a smooth surface in 17, and there was evidence of a tumor capsule in 15. Necrosis was depicted in 16 patients. There was no evidence of calcifications, central scar, fat, or abdominal lymphadenopathy. CT was performed in 20 patients. HCC was hypoattenuating on unenhanced CT scans in 14 patients, heterogeneously hyperattenuating in the arterial phase in 20, and hypoattenuating in the portal phase in 14. MR imaging was performed in 16 patients. HCC was hyperintense compared with liver parenchyma at T2-weighted MR imaging in all 16 patients, hypointense at T1-weighted imaging in 14, heterogeneously hyperintense at arterial phase T1-weighted imaging in 16, and hypointense at portal phase T1-weighted imaging in 14.

CONCLUSION

HCC in patients with NAFLD is more likely to manifest as a large solitary or dominant mass characterized by smooth and possibly encapsulated margins, necrosis, and hypervascularity.

Stepwise carcinogenesis of hepatocellular carcinoma in the cirrhotic liver: demonstration on serial MR imaging

PURPOSE

To demonstrate imaging findings of stepwise carcinogenesis of hepatocellular carcinoma (HCC) in cirrhosis at serial state-of-the-art MR imaging exams.

MATERIALS AND METHODS

In a retrospective search of the hospital archives, three patients were identified in which developing HCC was observed in serial MR examinations, with histopathology or alpha-fetoprotein (AFP) correlation. Image findings were assessed for signal intensity of the lesions at multiple sequences, including dynamic gadolinium-enhanced imaging.

RESULTS

Initial findings in patient A showed a small nodule with fatty infiltration that developed in HCC in follow-up MRI, comprised of low-grade dysplastic nodule (DN; DN I), high-grade DN (DN II), and eventually classic HCC. In patient B, increased signal intensity on T2-weighted images in a single DN among numerous regenerative nodules was the only initial sign. Follow up MRI showed further increase in signal intensity and increased neovascularity, which suggested focal HCC in a DN II. Patient C demonstrated gradually increasing neovascularity as only initial sign, with development of classic HCC over time.

CONCLUSION

MR imaging provides insight in various pathways of stepwise carcinogenesis of developing HCC in cirrhosis. This may further explain the genetic heterogeneity, and may facilitate early detection and better selection of patients for follow-up.

Cirrhosis: CT and MR imaging evaluation

In this article, we present the CT and MR imaging characteristics of the cirrhotic liver. We describe the altered liver morphology in different forms of viral, alcoholic and autoimmune end-stage liver disease. We present the spectrum of imaging findings in portal hypertension, such as splenomegaly, ascites and varices. We describe the patchy and lacelike patterns of fibrosis, along with the focal confluent form. The process of hepatocarcinogenesis is detailed, from regenerative to dysplastic nodules to overt hepatocellular carcinoma. Different types of non-neoplastic focal liver lesions occurring in the cirrhotic liver are discussed, including arterially enhancing nodules, hemangiomas and peribiliary cysts. We show different conditions causing liver morphology changes that can mimic cirrhosis, such as congenital hepatic fibrosis, "pseudo-cirrhosis" due to breast metastases treated with chemotherapy, Budd-Chiari syndrome, sarcoidosis and cavernous transformation of the portal vein.

Comparison between intravenous and intraarterial contrast injections for dynamic 3D MRI of liver tumors in the VX2 rabbit model

PURPOSE

To test the hypothesis that catheter-directed intraarterial (IA) contrast agent injection increases tumor enhancement and conspicuity compared to intravenous (IV) injection.

MATERIALS AND METHODS

Eight VX2 liver tumors were grown in five rabbits. After positioning a catheter in the hepatic artery, we performed 3D inversion recovery GRE MRI after IA and IV gadopentetate-dimeglumine contrast injections at doses of 0.04 and 0.1 mmol/kg, respectively. Peak enhancement (signal-to-noise ratio (SNR)) and conspicuity (contrast-to-noise ratio (CNR)) were measured for each acquisition.

RESULTS

The peak SNR and CNR were 21.7 +/- 5.8 and 17.0 +/- 4.8 (mean +/- SD) after IA injection, and 16.9 +/- 10.2 and 6.2 +/- 2.6 after IV injection. The IA CNR was significantly greater than the IV CNR (P < 0.05), with a >60% increase in CNR for each tumor. For six of the eight tumors the IA SNR was greater than the IV SNR, but statistical significance was not achieved due to the small sample size of the study (P = 0.07).

CONCLUSION

We demonstrated the feasibility of using IA injection techniques to improve tumor conspicuity. This strategy could be employed to enhance the detection of small liver tumors or to conserve contrast agent in future MRI-guided transcatheter liver therapies.