Hepatocellular carcinoma: MR imaging findings in cirrhotic livers and noncirrhotic livers

Focal Lesions of the Liver and Radiomics: What Do We Know?

Despite differences in pathological analysis, focal liver lesions are not always distinguishable in contrast-enhanced magnetic resonance imaging (MRI), contrast-enhanced computed tomography (CT), and positron emission tomography (PET). This issue can cause problems of differential diagnosis, treatment, and follow-up, especially in patients affected by HBV/HCV chronic liver disease or fatty liver disease. Radiomics is an innovative imaging approach that extracts and analyzes non-visible quantitative imaging features, supporting the radiologist in the most challenging differential diagnosis when the best-known methods are not conclusive. The purpose of this review is to evaluate the most significant CT and MRI texture features, which can discriminate between the main benign and malignant focal liver lesions and can be helpful to predict the response to pharmacological or surgical therapy and the patient's prognosis.

Multicentric Fibrolamellar Hepatocellular Carcinoma: A Rare Case Report

Multicentric fibrolamellar hepatocellular carcinoma has not been reported yet in the world as of our knowledge. A Medline search for the term “multicentric fibrolamellar HCC” did not return any results. To our knowledge, this is the first case report of multi-centric fibrolamellar hepatocellular carcinoma (HCC). We present the case of a 22-year-old male patient who had complaints of epigastric pain for 1 month. His general physical examinations were normal. Computed tomography of the abdomen revealed multiple hyper-enhancing space-occupying lesions, one of which showed a central scar. The final diagnosis of the case was multicentric fibrolamellar HCC, which was biopsy proven.

Comparing the CT and MRI findings for canine primary hepatocellular lesions

BACKGROUND

Triple-phase CT and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) MRI have been used to differentiate hepatocellular carcinomas (HCCs) in dogs.

METHODS

This retrospective case series aimed to compare the CT findings with MRI findings of 20 canine hepatocellular lesions, including eight poorly/moderately-differentiated HCCs, eight well-differentiated HCCs and four hyperplasias. CT data were analysed, and the following parameters were noted: vessel enhancement, enhancement pattern in the equilibrium phase, maximal transverse diameter, the lowest enhancement, and the attenuation values of each hepatocellular lesion in the precontrast and triple-phase series, including the arterial phase, portal phase and equilibrium phase. MRI data were analysed, and the following parameters were noted: signal intensities of each hepatocellular lesion on T2-weighted images and T1-weighted images, and signal intensity ratio of the hepatocellular lesions in the hepatobiliary phase.

RESULTS

In 62.5% of poorly/moderately-differentiated HCC and 75% of well-differentiated HCC, presumptive necrosis was detected on CT and MRI. In the hepatobiliary phase on MRI, the median signal intensity ratio of poorly/moderately-differentiated HCC (0.54 [range: 0.3-0.71]) was significantly lower than that of well-differentiated HCC (0.75 [range: 0.6-0.96]) and hyperplasia (0.79 [range: 071-0.98]; p = 0.02 and p = 0.02, respectively).

CONCLUSION

Gd-EOB-DTPA-enhanced MRI may be a superior modality for differentiating hepatocellular origin lesions.

Non-invasive imaging criteria for the diagnosis of hepatocellular carcinoma in non-cirrhotic patients with chronic hepatitis B

Background & Aims

Criteria defined by the European Association for the Study of the Liver (EASL) and Liver Imaging Reporting and Data System (LI-RADS) enable hepatocellular carcinoma (HCC) diagnosis based on imaging in cirrhosis. Non-cirrhotic patients require biopsy given the lower pre-test probability of HCC. The objective of our study was to assess the performance of EASL and LI-RADS criteria for the diagnosis of HCC in non-cirrhotic patients with chronic HBV infection.

Methods

This was a cross-sectional study performed at a referral center. We included all patients with HBV without cirrhosis with focal liver lesions who underwent contrast-enhanced CT or MRI at our clinic between 2005-2018. Studies were reviewed by 2 radiologists blinded to the diagnosis.

Results

We included 280 patients, median age was 56.8 (IQR 48.2-65.45) years and 223 (80%) were male. In 191 (79%) cases the lesion was found as a result of screening. Cirrhosis was excluded based on pathology in 252 (90%) cases. We assessed 338 nodules: 257 (76%) HCC, 40 (12%) non-HCC malignant lesions, and 41 (12%) benign lesions. EASL criteria and LR-5/LR-tumor-in-vein (TIV) categories had a 100% agreement in categorizing lesions as HCC, and 226 nodules (67%) were classified as HCCs. The sensitivity, specificity, positive predictive value, and negative predictive value were 82.1 (76.9-86.6), 81.5 (71.3-89.2), 93.4 (89.3-96.2), and 58.9 (49.2-68.1), respectively. When the pre-test probability of HCC is >70%, estimated as a PAGE-B score above 9, and EASL or LR-5/LR-TIV criteria are met, post-test probability would be >90%.

Conclusions

EASL criteria and LR-5/LR-TIV categories show a positive predictive value in patients with HBV without cirrhosis that is comparable to that seen in patients with cirrhosis. These criteria can be used when the pre-test probability of HCC is >70%.

Lay summary

Current guidelines recommend performing a biopsy to confirm the diagnosis of presumed hepatocellular carcinoma (HCC) in patients without cirrhosis. We showed that specific imaging criteria had a 100% agreement for categorizing lesions as HCC, with a positive predictive value of 93.4%. These imaging criteria could be used to diagnose HCC in HBV patients without cirrhosis with a pre-test probability of HCC of ≥70%, avoiding the need for a liver biopsy.

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Imaging criteria defined by the EASL and LI-RADS enable the diagnosis of HCC without biopsy in patients with cirrhosis.

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A biopsy is recommended in all patients without cirrhosis.

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Imaging criteria had a good performance in patients with HBV infection without cirrhosis when pre-test probability was >70%.

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HCC may be diagnosed based solely on imaging criteria in patients with HBV subject to HCC screening (i.e. PAGE-B score >9).

Unusual presentation of hepatocellular carcinoma: Case report and review of literature

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver and a major cause of mortality globally. Atypical presentation of HCC can present a diagnostic challenge. We, therefore, present a rare case of hepatocellular carcinoma fungating through the anterior abdominal wall with concomitant lung and brain metastases in a young patient with non-cirrhotic liver but positive chronic hepatitis B serology.

Hepatocellular carcinoma in non-alcoholic fatty liver disease-a review of an emerging challenge facing clinicians

Importance

Non-alcoholic fatty liver disease (NAFLD) is a rapidly growing cause of chronic liver disease and is becoming a leading cause of hepatocellular carcinoma (HCC) in many developed countries. This presents major challenges for the surveillance, diagnosis and treatment of HCC.

Objective

To discuss the clinical challenges faced by clinicians in managing the rising number of NAFLD-HCC cases.

Evidence Review

MEDLINE, PubMed and Embase databases were searched using the keywords; NAFLD, HCC, surveillance, hepatectomy, liver transplantation, percutaneous ablation, transarterial chemoembolization (TACE), selective internal radiotherapy treatment (SIRT) and sorafenib. Relevant clinical studies were included.

Findings

Current HCC surveillance programmes are inadequate because they only screen for HCC in patients with cirrhosis, whereas in NAFLD a significant proportion of HCC develops in the absence of cirrhosis. Consequently NAFLD patients often present with a more advanced stage of HCC, with a poorer prognosis. NAFLD-HCC patients also tend to be older and to have more co-morbidities compared to HCC of other etiologies. This limits the use of curative treatments such as liver resection and orthotopic liver transplantation (OLT). Evidence suggests that although NAFLD-HCC patients who undergo liver resection or OLT have worse perioperative and short-term outcomes, overall long-term survival is comparable to HCC of other etiologies. This highlights the importance of careful patient selection, pre-habilitation and perioperative planning for NAFLD-HCC patients being considered for surgical treatment. Careful consideration is also important for non-surgical treatments, although the evidence supporting treatment selection is frequently lacking, as these patients tend to be poorly represented in clinical trials. Locoregional therapies such as percutaneous ablation and TACE may be less well tolerated and less effective in NAFLD patients with obesity or diabetes. The tyrosine kinase inhibitor sorafenib may also be less effective.

Conclusions and Relevance

This review highlights how international guidelines, for which NAFLD traditionally has made up a small part of the evidence base, may not be appropriate for all NAFLD-HCC patients. Future guidelines need to reflect the changing landscape of HCC, by making specific recommendations for the management of NAFLD-HCC.

Diagnostic performance of Liver Imaging Reporting and Data System (LI-RADS) v2017 in predicting malignant liver lesions in pediatric patients: a preliminary study

BACKGROUND

Liver Imaging Reporting and Data System (LI-RADS) has standardized the evaluation of hepatic lesions in adults at risk of developing hepatocellular carcinoma (HCC). There is no accepted imaging algorithm for diagnosing HCC in the pediatric population.

OBJECTIVE

The aim of our study was to evaluate the diagnostic accuracy and inter-rater reliability of LI-RADS version 2017 (v2017) for diagnosing HCC in a pediatric cohort.

MATERIALS AND METHODS

This retrospective, Institutional Review Board-approved study involved review of all abdominal dynamic contrast-enhanced imaging at a tertiary children's hospital during a 10-year period, yielding 151 liver lesions in patients <18 years. Cases with active extrahepatic malignancy or an inadequate reference standard were excluded. Two readers independently evaluated all included hepatic lesions using LI-RADS criteria. Pathology and imaging follow-up were used as reference standards.

RESULTS

A total of 41 lesions in 41 patients met criteria for evaluation (3 HCCs, 8 non-HCC malignancies, 30 benign lesions). A LI-RADS designation of definite HCC had high sensitivity (Reader 1/Reader 2: 100%, 95% confidence interval [CI] 31-100%) and high specificity (Reader 1: 84%, 95% CI: 68-93%; Reader 2: 97%, 95% CI: 85-100%) for predicting HCC. However, positive predictive value was only 33% (95% CI: 9-69%) and 75% (95% CI: 22-99%) for Reader 1 and Reader 2, respectively. For predicting any type of hepatic malignancy, a LI-RADS designation of definitely or likely malignant (i.e. not necessarily HCC) had a sensitivity of 100% (95% CI: 74-100%) and 90% (95% CI: 61-100%) for Reader 1 and Reader 2, respectively, and a negative predictive value (NPV) of 100% (95% CI: 81-100%) and 96% (95% CI: 83-99%) for Reader 1 and Reader 2, respectively. Interobserver agreement was substantial for the overall LI-RADS category (weighted κ=0.62; 95% CI: 0.38-0.86).

CONCLUSION

The positive predictive value of LI-RADS v2017 for diagnosing HCC was limited by the low frequency of HCC among pediatric patients. However, a LI-RADS designation of definitely or likely malignant had high sensitivity and NPV for any type of hepatic malignancy and may serve to direct clinical management by selecting patients for tissue sampling.

Hepatocellular carcinoma in non-cirrhotic liver: A comprehensive review

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, which in turns accounts for the sixth most common cancer worldwide. Despite being the 6^th most common cancer it is the second leading cause of cancer related deaths. HCC typically arises in the background of cirrhosis, however, about 20% of cases can develop in a non-cirrhotic liver. This particular subgroup of HCC generally presents at an advanced stage as surveillance is not performed in a non-cirrhotic liver. HCC in non-cirrhotic patients is clinically silent in its early stages because of lack of symptoms and surveillance imaging; and higher hepatic reserve in this population. Interestingly, F3 fibrosis in non-alcoholic fatty liver disease, hepatitis B virus and hepatitis C virus infections are associated with high risk of developing HCC. Even though considerable progress has been made in the management of this entity, there is a dire need for implementation of surveillance strategies in the patient population at risk, to decrease the disease burden at presentation and improve the prognosis of these patients. This comprehensive review details the epidemiology, risk factors, clinical features, diagnosis and management of HCC in non-cirrhotic patients and provides future directions for research.

MRI texture analysis for differentiation of malignant and benign hepatocellular tumors in the non-cirrhotic liver

Purpose

To find potentially diagnostic texture analysis (TA) features and to evaluate the diagnostic accuracy of two-dimensional (2D) magnetic resonance (MR) TA for differentiation between hepatocellular carcinoma (HCC) and benign hepatocellular tumors in the non-cirrhotic liver in an exploratory MR-study.

Materials and methods

108 non-cirrhotic patients (62 female; 41.5 ± 18.3 years) undergoing preoperative contrast-enhanced MRI were retrospectively included in this multi-center-study. TA including gray-level histogram, co-occurrence and run-length matrix features (total 19 features) was performed by two independent readers. Native fat-saturated-T1w and T2w as well as arterial and portal-venous post contrast-enhanced 2D-image-slices were assessed. Conventional reading was performed by two separate independent readers. Differences in TA features between HCC and benign lesions were investigated using independent sample t-tests. Logistic regression analysis was performed to obtain the optimal number/combination of TA-features and diagnostic accuracy of TA analysis. Sensitivity and specificity of the better performing radiologist were compared to TA analysis.

Results

The highest number of significantly differing TA-features (n = 5) was found using the arterial-phase images including one gray-level histogram (skewness, p = 0.018) and four run-length matrix features (all, p < 0.02). The optimal binary logistic regression model for TA-features of the arterial-phase images contained 13 parameters with an accuracy of 84.5% (sensitivity 84.1%, specificity 84.9%) and area-under-the-curve of 0.92 (95%-confidence-interval 0.85–0.98) for diagnosis of HCC. Conventional reading yielded a significantly lower sensitivity (63.6%, p = 0.027) and no significant difference in specificity (94.6%, p = 0.289) at best.

Conclusion

2D-TA of MR images is a feasible objective method that may help to distinguish HCC from benign hepatocellular tumors in the non-cirrhotic liver. Most promising results were found in TA features in the arterial phase images.

Primary malignant tumours in the non-cirrhotic liver

Intrahepatic chlangiocarcinomas (CCs), the second most common primary malignant liver tumours, usually occur in non-cirrhotic liver, and can be classified into three types based on gross morphology: mass-forming; periductal infiltrating; and intraductal growing. Among them, mass-forming intrahepatic CCs are the most common type and characterized by homogeneous mass with an irregular but well-defined margin with peripheral enhancement on late arterial phase and delayed enhancement in central portion of tumours corresponding to the fibrous stroma. Several imaging features such as enhancement pattern and degree of diffusion restriction have been suggested as prognostic markers for mass-forming CCs. Hepatocellular carcinomas (HCCs) are the most common primary malignant liver tumors, and usually arise from the cirrhotic liver. However, approximately 20% of HCCs involve the non-cirrhotic liver (hereafter, non-cirrhotic HCC), and non-cirrhotic HCCs are often detected at an advanced stage due to the lack of surveillance for patients with non-cirrhotic liver. Other primary malignant liver tumours other than CCs and HCCs including angiosarcoma, undifferentiated embryonal sarcoma are quite rare, and imaging diagnosis is often difficult. This review offers a brief overview of epidemiology, risk factors and imaging features of primary malignant tumours in non-cirrhotic liver. Understanding of radiologic appearance and predisposing clinical features as well as differentials of primary malignant tumour in non-cirrhotic liver can be helpful for radiologists to adequately assess these tumours, and subsequently to make optimal management plan.

Diagnostic Imaging of Hepatocellular Carcinoma - A Pictorial Essay

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, which develops mostly in the setting of chronic liver disease. European Association for the Study of the Liver (EASL) and European Organization for Research and Treatment of Cancer (EORTC) prepared guidelines for screening, follow-up and diagnosis of HCC to facilitate decision making and optimize both diagnostic and therapeutic protocols. The review briefly describes etiology, epidemiology and histopathology of HCC and presents EASL-EORTC guidelines for surveillance and diagnosis of HCC. Target population and screening algorithm is presented in the surveillance section. Ultrasound imaging of HCC and the role of contrast enhanced ultrasound are described as well as the value of laboratory tests in screening. Further, radiological features of HCC in multiphase CT and dynamic contrast enhanced MRI and diagnostic criteria are presented. Additionally, the advantages of advanced techniques in MRI such as diffusion weighed imaging and the use of hepatocyte-specific contrast agents are discussed. Lastly, the EASL-EORTC guidelines are compared with the guidelines of the American Association for the Study of Liver Diseases and the Japan Society of Hepatology. Also LI-RADS and the Barcelona Clinic Liver Cancer classification are mentioned. In the near future, due to the ongoing advances in imaging a revision of the guidelines may be expected.

Contemporary management of fibrolamellar hepatocellular carcinoma: diagnosis, treatment, outcome, prognostic factors, and recent developments

Fibrolamellar hepatocellular carcinoma (FL-HCC) is a malignant liver tumor which is thought to be a variant of conventional hepatocellular carcinoma (HCC). It accounts for a small proportion of HCC cases and occurs in a distinctly different group of patients which are young and usually not in the setting of chronic liver disease. The diagnosis of FL-HCC requires the integration of clinical information, imaging studies, and histology. In terms of the treatment options, the only potentially curative treatment option for patients who have resectable disease is surgery either liver resection (LR) or liver transplantation (LT). When performed in a context of aggressive therapy, long-term outcomes after surgery, particularly liver resection for FL-HCC, were favorable. The clinical outcome of patients with unresectable disease is suboptimal with median survival of less than 12 months. The aim of this review is to update the available evidence on diagnosis, treatment options, outcome predictors, and recent developments of patients with this rare disease and to provide a summarized overview of the available literature.

MDCT features of hepatocellular carcinoma (HCC) in non-cirrhotic liver

PURPOSE

To describe the multidetector row computed tomography (MDCT) imaging features of HCC that develops in patients who are free from underlying liver cirrhosis and to determine if the MDCT presentation of this specific tumor differs from that of the more common HCC that develops in patients with liver cirrhosis using a retrospective case-control study.

PATIENTS AND METHODS

The MDCT examinations of 38 patients with HCC in non-cirrhotic liver (group 1) were quantitatively and qualitatively analyzed and compared to those obtained in 38 patients with HCC in cirrhotic liver (group 2) matched for age and gender. Quantitative and qualitative characteristics of HCC of both groups were compared using univariate analysis.

RESULTS

HCCs were significantly larger in group 1 (81.5mm±55.5) than in group 2 (44.5mm±39.1 SD; P=0.0015). In group 1, HCCs were more frequently single tumors (87%) than in group 2 (37%) (P<0.0001), encapsulated (92% vs. 47% respectively; P<0.0001), had more frequently fatty component (24% vs. 8%, respectively; P=0.0279) and internal hemorrhage (29% vs. 3%, respectively; P=0.0033). No significant differences were found between the two groups for location, hyperenhancement of HCC during the arterial phase, washout during the portal phase, endoluminal portal involvement by HCC, endoportal cruoric thrombus, invasion of adjacent organs and underlying liver steatosis.

CONCLUSION

HCC in non-cirrhotic liver are larger than those observed in cirrhotic liver and more frequently present as a single encapsulated tumor. They have the same patterns of enhancement than HCC that develops in cirrhotic liver.

Imaging Diagnosis of Splanchnic Venous Thrombosis

Splanchnic vein thrombosis (SVT) is a broad term that includes Budd-Chiari syndrome and occlusion of veins that constitute the portal venous system. Due to the common risk factors involved in the pathogenesis of these clinically distinct disorders, concurrent involvement of two different regions is quite common. In acute and subacute SVT, the symptoms may overlap with a variety of other abdominal emergencies while in chronic SVT, the extent of portal hypertension and its attendant complications determine the clinical course. As a result, clinical diagnosis is often difficult and is frequently reliant on imaging. Tremendous improvements in vascular imaging in recent years have ensured that this once rare entity is being increasingly detected. Treatment of acute SVT requires immediate anticoagulation. Transcatheter thrombolysis or transjugular intrahepatic portosystemic shunt is used in the event of clinical deterioration. In cases with peritonitis, immediate laparotomy and bowel resection may be required for irreversible bowel ischemia. In chronic SVT, the underlying cause should be identified and treated. The imaging manifestations of the clinical syndromes resulting from SVT are comprehensively discussed here along with a brief review of the relevant clinical features and therapeutic approach.

MR imaging features for improved diagnosis of hepatocellular carcinoma in the non-cirrhotic liver: Multi-center evaluation

PURPOSE

To determine MR-imaging features for the differentiation between hepatocellular carcinoma (HCC) and benign hepatocellular tumors in the non-cirrhotic liver.

MATERIAL AND METHODS

107 consecutive patients without liver cirrhosis (46 male; 45 ± 14 years) who underwent liver resection due to suspicion of HCC were included in this multi-center study. The following imaging features were assessed: lesion diameter and demarcation, satellite-lesions, central-scar, capsule, fat-content, hemorrhage, vein-infiltration and signal-intensity (SI) on native T1-, T2- and dynamic-enhanced T1-weighted images (center versus periphery). In addition, contrast-media (CM) uptake in the liver specific phase was analyzed in a sub-group of 42 patients.

RESULTS

Significant differences between HCC (n=55) and benign lesions (n=52) were shown for native T1-, T2- and dynamic-enhanced T1-SI, fat-content, and satellite-lesions (all, P<.05). Independent predictors for HCC were T1-hypointensity (odds-ratio, 4.81), T2-hypo-/hyperintensity (5.07), lack of central tumor-enhancement (3.36), and satellite-lesions (5.78; all P<0.05). Sensitivity and specificity of HCC was 91% and 75% respectively for two out-of four independent predictors, whereas specificity reached 98% for all four predictors. Sub-analysis, showed significant differences in liver specific CM uptake between HCC (n=18) and benign lesions (n=24; P<0.001) and revealed lack of liver specific CM uptake (odds-ratio, 2.7) as additional independent feature for diagnosis of HCC.

CONCLUSION

Independent MRI features indicating HCC are T1-hypointensity, T2-hypo- or hyperintensity, lack of central tumor-enhancement, presence of satellite-lesions and lack of liver specific CM-uptake. These features may have the potential to improve the diagnosis of HCC in the non-cirrhotic liver.

Imagiological Diagnosis of Gastrointestinal Diseases - Diagnostic Criteria of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of neoplastic morbidity and mortality worldwide, and despite recent treatment advances, the prognosis remains dismal, with a 5-year mortality rate of 85%.

The surveillance and timely diagnosis is therefore of crucial importance in order to improve survival rates and alleviate the health burden imposed by the HCC.

Previously, HCC diagnosis warranted liver biopsy, an invasive process with limited diagnostic accuracy. In the past 15 years, HCC diagnosis based solely on imaging criteria was accepted by all the major national and international guidelines, and is now widely employed across the globe.

Current European guidelines for the HCC diagnosis support the use of both dynamic contrasted computer tomography as well as magnetic resonance imaging for the non-invasive diagnosis of HCC for nodules >1 cm in a cirrhotic liver. The non-invasive diagnosis of HCC depends on radiological hallmarks, such as homogeneous contrast uptake during the arterial phase and wash-out during the venous and late phases, but while such tumoral behaviour is frequent in nodules >2 cm, high-end equipment and superior expertise is often needed for the correct diagnosis of early HCC.

Nevertheless, the accuracy of imaging techniques for the diagnosis of HCC is permanently improving, and supports the progressively reduced need for liver biopsy during liver nodule workout in a cirrhotic liver.

CT and MRI of primary and metastatic fibrolamellar carcinoma: a case series of 37 patients

OBJECTIVE

Fibrolamellar carcinoma (FLC) is a rare disease, with limited radiographic reported information. We assessed the imaging patterns of primary and metastatic FLC.

METHODS

CT and MR examinations of patients with FLC were retrospectively reviewed. Imaging features were assessed for primary and recurrent liver tumours, including dimension, enhancement characteristics, and presence or absence of central scars. Locations of nodal and extranodal metastases were also recorded.

RESULTS

Of 37 patients (18 males and 19 females; average age, 23.5 years) with FLC, 24 had imaging of their primary tumour; 13 had metastases at presentation and 7 developed metastases on follow-up. The remaining 13 patients had follow-up imaging of metastatic disease. Primary FLC had a mean diameter >11 cm, with central scars in ten (46%) patients. Most tumours enhanced heterogeneously (96%) and showed arterial enhancement (81%). On MRI, 62% of FLCs were hypointense on T1 weighted imaging and 54% were hyperintense on T2 weighted imaging. 13 patients (54%) had nodal metastases at presentation, mostly in the upper abdomen (92%) and commonly in the chest (38%). Extrahepatic metastases were most frequently pulmonary or peritoneal. Predominantly small and homogeneous intrahepatic recurrences were detected on follow-up in 15 patients.

CONCLUSION

FLC often presents as a large hepatic tumour with nodal and distant metastases. Thoracic adenopathy and lung metastases were frequently found in our series, suggesting the need for pre-operative and follow-up chest imaging.

ADVANCES IN KNOWLEDGE

Thoracic nodal and lung metastases are common in FLC; therefore, dedicated chest imaging should be part of the evaluation of a patient with FLC.

Imaging features of fibrolamellar hepatocellular carcinoma

OBJECTIVE

Fibrolamellar hepatocellular carcinoma (HCC) is a rare primary liver tumor, which significantly differs from conventional HCC. This article reviews the molecular cytogenetics, pathology, imaging features, and management of this relatively rare tumor.

CONCLUSION

Fibrolamellar HCC predominantly occurs in young patients without underlying hepatitis or cirrhosis. Serum α-fetoproteins are not elevated in most cases, and hence imaging plays an important role in diagnosis, staging, and surveillance.

Hepatocellular carcinoma in chronic hepatitis C in the absence of advanced fibrosis or cirrhosis

OBJECTIVE

The objective of our study was to describe the cross-sectional imaging appearance of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C virus (HCV) infection in the absence of advanced fibrosis and cirrhosis.

MATERIALS AND METHODS

This study is a retrospective review of our surgical database to identify patients with chronic HCV infection and HCC who underwent hepatectomy and who had undergone preoperative CT or MRI. Only patients with a Metavir fibrosis score of F0, F1, or F2 on pathology were included. Patients with hepatitis B virus coinfection or other causes of chronic liver disease and patients with histopathologic evidence of advanced fibrosis or cirrhosis (Metavir scores F3 and F4) were excluded. Contrast-enhanced CT or MRI examinations performed within 2 months before surgery were reviewed for the number, size, and location of tumors; tumor enhancement characteristics; and presence of macrovascular invasion.

RESULTS

Two hundred forty-five resections of HCC in patients with HCV were performed in our institution from 1987 to 2012. Of this group, 26 patients (10.6%) had a Metavir fibrosis score of F0, F1, or F2; of those patients, 19 (18 men and one woman; 18 non-Asian patients and one Asian patient; mean age, 64 years) had imaging studies available for review. Twenty-one HCCs (mean size, 4.5 cm; range, 0.9-14.8 cm) were evaluated at imaging. Typical wash-in and washout characteristics were seen in 16 of 19 viable lesions (84.2%). The remaining two HCCs were completely necrotic after transarterial chemoembolization. Eighteen patients had a solitary tumor. Most tumors (15/21, 71.4%) developed in the right hepatic lobe.

CONCLUSION

HCC can develop in patients with chronic HCV without advanced fibrosis or cirrhosis, most frequently in older non-Asian men, and usually appears as a large solitary tumor with a typical wash-in-washout enhancement pattern.

Hepatocellular carcinoma associated with Budd-Chiari syndrome: imaging features and transcatheter arterial chemoembolization

Background

Budd–Chiari syndrome (BCS) often leads to hepatocellular carcinoma (HCC). Transcatheter arterial chemoembolization (TACE) has been increasingly used to treat BCS patients with HCC. The purposes of this study were to illustrate imaging features in BCS patients with HCC, and to analyze the effects of TACE on BCS patients with HCC.

Methods

246 consecutive patients with primary BCS were retrospectively studied. 14 BCS patients with HCC were included in this study. BCS were treated with angioplasty and/or stenting, and HCC were managed with TACE. Imaging features on ultrasonography, CT, MRI, and angiography and the serum AFP level were analyzed.

Results

Inferior vena cava block and stricture of hepatic venous outflow tract more frequently occurred. Portal vein invasion was found in only 2 patients (14.2%). Imaging studies showed that most nodules of HCC were near the edge of liver, irregular, more than 3 cm in diameter, heterogeneous mass and solitary (≤3 nodules). HCC in patients associated with BCS was isointense or hypointense in nonenhanced CT images, and exhibited heterogeneous enhancement during the arterial phase and washout during the portal venous phase on enhanced CT and MRI. The serum AFP level significantly declined after TACE treatment.

Conclusions

BCS patients with inferior vena cava block and stricture of hepatic venous outflow tract seems to be associated with HCC. A single, large, irregular nodule with a peripheral location appears to be HCC. TACE can effectively treat HCC in BCS patients.

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.

Diagnostic sensitivity of hepatocellular carcinoma imaging and its application to non-cirrhotic patients

BACKGROUND AND AIMS

The American Association for the Study of Liver Disease issued guidelines that proposed that hepatocellular carcinoma (HCC) can be diagnosed if a mass is larger than 2 cm in a cirrhotic liver and shows typical features of HCC at triphasic liver computed tomography (CT) or dynamic magnetic resonance imaging (MRI). In non-cirrhotic livers, the criteria were not applicable. The aim of the present study was to retrospectively analyze the sensitivity of imaging by samples of definite HCC postoperatively and test their application to diagnose HCC in non-cirrhotic livers.

METHODS

From January 2006 to November 2008, a total of 343 pathologically-diagnosed HCC patients via surgical resection were reviewed. Among the 343 patients, 204 patients had undergone liver CT examination, and 80 patients underwent MRI examination; serum α-fetoprotein had been checked for all 343 patients prior to operation. The diagnostic sensitivity of HCC by imaging was evaluated and compared in patients with/without cirrhosis by ultrasound and histology.

RESULTS

The diagnostic sensitivity of HCC by single imaging was approximately 65-80% (liver CT or MRI). A higher sensitivity of HCC diagnosis was found in patients with ultrasound-diagnosed cirrhosis than non-cirrhosis, but the difference in sensitivity disappeared after histologically-cirrhotic validation. The results indicated that regardless of the presence or absence of cirrhosis (histology), a typical vascular pattern could diagnose HCC with equally high sensitivity.

CONCLUSIONS

We provide evidence that the sensitivity of HCC diagnosis by imaging is not influenced by the cirrhotic background. Further study is needed to validate the specificity and accuracy.

Cirrhosis and lesion characterization at MR imaging

Magnetic resonance (MR) imaging has emerged as an important imaging modality for the assessment of cirrhosis and its complications. Faster sequences now allow high-quality liver imaging with high intrinsic soft-tissue contrast. Automated contrast detection methods in combination with faster sequences allow reproducible capture of the arterial phase, which is essential for the detection and characterization of hepatocellular carcinoma. The lack of ionizing radiation permits routine use of gadolinium-enhanced three-dimensional (3D) fat-suppressed multiphasic imaging with high temporal and spatial resolution. In addition, MR imaging allows simultaneous evaluation of the background liver parenchyma and the liver lesions with the combined use of sequences that include T2-weighted sequences, T1-weighted sequences (including chemical shift imaging), echoplanar diffusion-weighted sequences, dynamic gadolinium-enhanced 3D multiphasic imaging, and liver-specific delayed phase sequences (if contrast agents with hepatobiliary excretion are used). The combination of findings from different sequences often helps pinpoint the nature of the liver abnormalities.

Receiver operating characteristic analysis of diffusion-weighted magnetic resonance imaging in differentiating hepatic hemangioma from other hypervascular liver lesions

PURPOSE

To evaluate the role of diffusion-weighted imaging in differentiating between hepatic hemangiomas, both typical and atypical, and other hypervascular liver lesions.

METHODS

Retrospective review of 182 hypervascular liver lesions in 117 patients was performed. Diffusion and contrast-enhanced magnetic resonance imaging were performed using a 1.5-T unit. Imaging protocol consisted of T2-weighted fast spin-echo images, breath-hold diffusion-weighted echo-planar images, and breath-hold unenhanced and contrast-enhanced T1-weighted 3-dimensional fat-suppressed spoiled gradient-echo images in the arterial phase (20 seconds) and portal venous phase (60 seconds). Signal intensity changes and apparent diffusion coefficient (ADC) values were evaluated for all lesions. Unpaired t test was used to compare the mean ADC values for different lesions, and statistical significance was set at P < 0.01. Receiver operating characteristic analysis was used to determine the accuracy of diffusion-weighted imaging in differentiating hemangiomas from other hypervascular liver lesions.

RESULTS

Lesions included typical and atypical hemangioma (n = 38), hepatocellular carcinoma (HCC; n = 58), focal nodular hyperplasia (FNH; n = 22), and neuroendocrine tumor metastasis (NET; n = 64) with a mean tumor size of 5.3 cm. Mean ADC value for hemangioma, HCC, FNH, and NET was 2.29 x 10(-3), 1.55 x 10(-3), 1.65 x 10(-3), and 1.43 x 10(-3) mm2/s, respectively. There was a statistically significant difference in the ADC value of hemangioma compared with that of FNH (P < 0.001), HCC (P < 0.001), and NET (P < 0.001), respectively. The area under the receiver operating characteristic curve was 0.91.

CONCLUSIONS

Diffusion-weighted magnetic resonance imaging and ADC maps can provide rapid quantifiable information to differentiate typical and atypical hemangiomas from other hypervascular liver lesions.

Magnetic resonance imaging of liver lesions: exceptions and atypical lesions

On state-of-the-art magnetic resonance imaging, most lesions can be detected and characterized with confidence according to well-known criteria. However, atypical characteristics in some common lesions and the incidental encounter with rare lesions may pose diagnostic difficulties. In this article, six challenging hepatic lesions will be discussed and evaluated on the most important magnetic resonance imaging sequences, with histological correlation when available. In addition, the background information concerning these lesions will be described based on the most recent available literature. By reading this article, the reader will be able to (1) categorize the lesion in solid and fluid-containing lesions, based on the T2 signal intensity; and (2) define the benign or malignant nature of the lesion, in relation to the signal intensity and dynamic enhancement pattern, despite the presence of atypical characteristics of some lesions.

Hepatoid adenocarcinoma of the gallbladder: a mimicker of hepatocellular carcinoma

We present a case of a large gallbladder tumour in a patient with no known liver disease and elevated alpha-fetoprotein (AFP), in whom a differential diagnosis from hepatocellular carcinoma (HCC) in a non-cirrhotic liver was particularly difficult given the combination of the size of the tumour, solitary nature, elevated AFP and striking resemblance with HCC at histology. In presenting this patient, we would like to emphasise the role of MRI as a problem-solving tool for analysis of rare tumours of non-hepatocellular origin, including hepatoid adenocarcinoma of the gallbladder.

Magnetic resonance imaging of the liver: a review

In this review article, the authors discuss the essential aspects of liver magnetic resonance imaging (MRI), including protocol, intravenous contrast use and disease entities. At present, liver MRI uses fast scanning techniques, allowing the maximization of the principles of image quality, reproducibility of image quality and good conspicuity of disease. MRI is the most accurate imaging modality for the detection and characterization of diffuse and focal liver disease. In the expert opinion section, the authors refer to the advantages and challenges of 3.0T liver imaging.

Liver MR Imaging: 1.5T versus 3T

This article focuses on technical challenges in transferring 1.5T liver protocols to 3T systems and the overall comparison of MR sequences, highlighting the advantages and disadvantages of imaging at the higher field strength. An important benefit is the capacity of acquiring high-quality, thin-section postgadolinium T1-weighted three-dimensional gradientecho sequences, most clinically relevant for the detection and characterization of small hypervascular malignant diseases. Further research and development is necessary to overcome disadvantages, such as with in- and out-of phase T1-weighted gradient-echo sequences, and to minimize artifacts that appear at 3T.

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.

Evaluation of primary malignancies of the liver using contrast-enhanced sonography: correlation with pathology

OBJECTIVE

Our purpose was to investigate the correlation of contrast-enhanced sonographic patterns with the histopathology of primary malignancies of the liver.

MATERIAL AND METHODS

Of the 318 contrast-enhanced sonographic examinations performed between April and September 2004, 95 patients with 117 lesions confirmed by surgery or biopsy pathology were reviewed in this study. We analyzed the enhancement time and patterns according to the types and degrees of pathologic differentiation.

RESULTS

All 65 moderately to poorly differentiated hepatocellular carcinomas (HCCs) enhanced in the arterial phase, and 96.9% (63 lesions) of them quickly washed out in the portal venous phase. All 32 well-differentiated HCCs enhanced in the arterial phase, and 50.0% (16 lesions) washed out slowly during the late phase. The washout time of the two differentiated types was significantly different (p < 0.05). Seventy-five percent of the clear cell carcinomas (12/16) enhanced in the arterial phase, 25% (4/16) did not enhance until the portal venous phase, and 31.3% (5/16) of the clear cell carcinomas washed out slowly during the late phase. The enhancement and washout times of clear cell carcinomas were significantly different than those of moderately to poorly differentiated HCCs (p < 0.05). All four intrahepatic cholangiocarcinomas presented the same patterns as moderately to poorly differentiated HCCs: enhanced in the arterial phase and quickly washed out in the portal venous phase. Among the 72 lesions enhanced homogeneously, 46 lesions (63.9%) were smaller than 3 cm. Thirty-seven lesions (82.2%) of the 45 lesions that enhanced heterogeneously were larger than 3 cm (including the four cholangiocarcinomas). Larger lesions were mainly less differentiated. There were significant differences in tumor sizes in regard to cellular differentiations and types.

CONCLUSION

Our study showed that the enhancement manifestations of primary malignancies of the liver are related to pathologic types and grades. Contrast-enhanced sonograms may provide the histopathologic information for malignant tumors of the liver.

Contrast-enhanced dynamic magnetic resonance imaging findings of hepatocellular carcinoma and their correlation with histopathologic findings

PURPOSE

To investigate the correlations of contrast-enhanced magnetic resonance (MR) imaging findings of large (> 5 cm) hepatocellular carcinomas with tumor size and histopathologic findings.

MATERIALS AND METHODS

MR imaging was performed in 30 patients with a histopathologic diagnosis of hepatocellular carcinoma. The imaging protocol included non-contrast, hepatic arterial, portal venous and late phases. The signal intensities relative to the liver, enhancement patterns and the morphologic features of the lesions were evaluated in relation to size and degree of differentiation.

RESULTS

On histopathologic examination, 12 of 30 (40%) tumors were well-differentiated (grade 1), 6 of 30 (20%) were moderately differentiated (grades 2 and 3) and 12 of 30 (40%) were poorly differentiated (grade 4). Tumor size, tumor boundry, serum alpha-fetoprotein level and portal vein invasion were found to have statistically significant correlations with the degree of differentiation (p < 0.05). Portal vein invasion, capsule formation and tumor surface characteristics showed statistically significant correlations with tumor size (p < 0.05).

CONCLUSION

MR imaging findings of hepatocellular carcinomas larger than 5 cm are partially dependent on tumor size and degree of differentiation.

Controversies in imaging of hepatocellular carcinoma: multidetector CT (MDCT)

Primary hepatocellular carcinoma (HCC) is a significant tumor worldwide and represents the most common primary hepatic neoplasm. Staging criteria are important for appreciation of timely work up of these neoplasms in contradiction with surgical colleagues. This article demonstrates the appearance of HCC on multiphasic, multidetector CT (MDCT) and relates these findings to current staging criteria. The variable appearance on different planes of contrast is critical to appreciate in staging this neoplasm. The hypervascular nature of the primary tumor makes MDCT and three-phase imaging a critical feature in the detection and characterization of this tumor. This is especially critical in the patients who are candidates for surgical resection. Additionally, MDCT has allowed arterial phase imaging to define the vascular supply of the tumor. An accurate representation of the size and number of lesions is critical in not only the initial staging but also the follow-up of hepatocellular carcinoma. The post-treatment features including the appearance post-surgically and after radiofrequency ablation can be well appreciated on MDCT.

Magnetic resonance imaging of hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common primary hepatic malignancy, usually develops in patients with cirrhosis, growing sequentially from low-grade dysplastic nodules to frank malignant HCC. Its recognition is critical because curative treatment and prognosis require early diagnosis. Survival in patients with HCC relates directly to the number, size, and extent of lesions at diagnosis. Imaging of HCC is complicated because the tumor has a varied imaging appearance and frequently coexists with other cirrhotic nodules. Magnetic resonance imaging (MRI), the best available diagnostic technique, offers good contrast resolution and diagnostic sensitivity ranging from 33% to 77%. The main difficulty is not in diagnosing large tumors, but rather small tumors (<2 cm), because of considerable overlap on imaging between benign (regenerative), borderline (dysplastic), and malignant nodules. Increasing degrees of histological malignancy are associated with increasing arterialization and loss of portal blood supply; therefore, recognition of HCC requires dynamic imaging with gadolinium-enhanced T1-weighted sequence. Typically, HCC is a focal lesion with high signal intensity on T2-weighted images, variable signal intensity on T1-weighted images, intense arterial phase enhancement after gadolinium injection, and isointensity or hypointensity at the portal venous phase. The sensitivity of MRI for detecting small lesions is low, and improvement is still needed. Newer contrast agents, higher field strength (3 Tesla) imaging, and perfusion and diffusion MRI techniques possibly will provide greater sensitivity and specificity for detecting small HCCs in the future.

Improved characterization of liver lesions with liver-phase uptake of liver-specific microbubbles: prospective multicenter study

PURPOSE

To evaluate in a prospective multicenter study whether conventional ultrasonographic (US) characterization of liver lesions can be improved by imaging during the liver-specific phase of SH U 508A uptake in the microbubble-specific agent detection imaging mode.

MATERIALS AND METHODS

One hundred forty-two patients with liver lesions underwent conventional gray-scale and color Doppler US and SH U 508A-enhanced US. Two radiologists blindly read digital cine clips and assigned scores for confidence in diagnosis of benignancy or malignancy, diagnosis of specific lesion types, and relative difference in SH U 508A uptake between the lesion and the liver parenchyma (ie, subjective conspicuity score [SCS]). Comparisons were made to see whether the addition of agent detection imaging led to improved diagnostic performance.

RESULTS

Receiver operating characteristic analysis revealed improved discrimination of benign and malignant lesions for readers 1 (P =.049) and 2 (P <.001). The number of patients with a correct diagnosis of benignancy or malignancy assigned by readers 1 and 2, respectively, improved from 114 and 113 to 125 and 128 with agent detection imaging (reader 1: P =.027; reader 2: P =.008; McNemar test). Specific diagnoses were made more accurately with agent detection imaging: At McNemar testing, the number of correct lesion type determinations increased from 83 to 92 (P =.022) for reader 1 and from 85 to 99 (P <.001) for reader 2. Both readers assigned high scores for differences in SH U 508A uptake between the liver parenchyma and the lesion for metastases and cholangiocarcinomas and low scores for uptake differences in most of the benign lesions. Hepatocellular carcinomas (HCCs), hemangiomas, and adenomas had more variable uptake differences. Fourteen of 22 hemangiomas were assigned an SCS of less than 50%, and 22 (reader 1) and 15 (reader 2) of 31 HCCs were assigned an SCS of greater than 50%.

CONCLUSION

With use of SH U 508A-enhanced agent detection imaging, liver lesion characterization and diagnostic performance are significantly improved.

Benign versus malignant hepatic nodules: MR imaging findings with pathologic correlation

According to the currently used nomenclature, there are only two types of hepatocellular nodular lesions: regenerative lesions and dysplastic or neoplastic lesions. Regenerative nodules include monoacinar regenerative nodules, multiacinar regenerative nodules, cirrhotic nodules, segmental or lobar hyperplasia, and focal nodular hyperplasia. Dysplastic or neoplastic nodules include hepatocellular adenoma, dysplastic foci, dysplastic nodules, and hepatocellular carcinoma (HCC). Many of these types of hepatic nodules play a role in the de novo and stepwise carcinogenesis of HCC, which comprises the following steps: regenerative nodule, low-grade dysplastic nodule, high-grade dysplastic nodule, small HCC, and large HCC. State-of-the-art magnetic resonance (MR) imaging facilitates detection and characterization in most cases of hepatic nodules. State-of-the-art MR imaging includes single-shot fast spin-echo imaging, in-phase and opposed-phase T1-weighted gradient-echo imaging, T2-weighted fast spin-echo imaging with fat saturation, and two-dimensional or three-dimensional dynamic multiphase contrast material-enhanced imaging.

Benign regenerative nodules in Budd-Chiari syndrome and other vascular disorders of the liver: radiologic-pathologic and clinical correlation

Large regenerative nodules are benign liver lesions that are frequently seen in Budd-Chiari syndrome and less commonly in other vascular disorders of the liver or systemic conditions such as autoimmune disease, myeloproliferative disorders, and lymphoproliferative disorders. They are usually multiple, with a typical diameter of 0.5-4 cm. At pathologic analysis, large regenerative nodules are well-circumscribed, round lesions that may distort the contour of the liver. Only a minority of these nodules are detected at cross-sectional imaging. At multiphasic helical computed tomography, large regenerative nodules are markedly and homogeneously hyperattenuating on arterial dominant phase images and remain slightly hyperattenuating on portal venous phase images. Large regenerative nodules are bright on T1-weighted magnetic resonance images and show the same enhancement characteristics after intravenous bolus administration of gadolinium contrast material. They are predominantly isointense or hypointense relative to the liver on T2-weighted images. There is no evidence that large regenerative nodules degenerate into malignancy. If these nodules are misdiagnosed as multifocal hepatocellular carcinoma, patients might be denied transplantation or offered inappropriately aggressive therapy such as transcatheter arterial chemoembolization. Understanding the clinical setting and imaging appearance of large regenerative nodules can help avoid misdiagnosis as other hypervascular masses.

MR imaging of hepatocellular carcinoma

In this article, MR imaging features of hepatocellular carcinoma (HCC) are described. To better understand the MR imaging features of HCC, recent progress regarding its etiology, treatment, carcinogenesis, histology, and gross pathology will be described. Currently, T2-weighted fast spin-echo with fat saturation, and multiphasic dynamic gadolinium-enhanced two-dimensional and three-dimensional T1-weighted gradient echo imaging provides excellent results for detection and characterization of HCC.

Detection of nodules in liver cirrhosis: spiral computed tomography or magnetic resonance imaging? A prospective study of 88 nodules in 34 patients

Detection and characterization of all focal lesions in the liver are critical for screening patients with chronic liver disease. The aim of this prospective study was to investigate the accuracy of magnetic resonance imaging (MRI) and spiral computed tomography for the diagnosis of hepatic nodules in cirrhotic patients when compared with pathological findings of the explanted liver. From February 1997 to July 1999, 34 cirrhotic patients waiting for orthotopic liver transplantation (OLT) (mean age, 53.5 +/- 9.3 years; 24 males) were included. All patients had MRI and spiral computed tomography examinations, and findings were matched with the histological findings. Data analyses were made using the McNemar chi-square test. Mean time between radiological examination (MRI or spiral computed tomography) and OLT was 43.8 +/- 39 days. A total of 88 nodules were found in the 34 patients: 54 hepatocellular carcinoma (HCC) (mean size, 18 +/- 10 mm) in 21 patients, 22 dysplastic nodules (mean size, 10.7 +/- 4.3 mm) in 11 patients, and 12 macroregenerative nodules in 13 patients. Lesion-by-lesion analyses showed that sensitivity of MRI and spiral computed tomography for nodule, HCC or dysplastic nodule diagnosis was 44.3 and 31.8% (P = 0.02), 61.1 and 51.9% (P = 0.2), and 27.3 and 0% (P = 0.04), respectively. Patient-by-patient analyses showed no statistical difference between spiral computed tomography and MRI for nodule diagnosis. In conclusion, in patients with liver cirrhosis, MRI is more accurate than spiral computed tomography for the detection of liver nodules and dysplastic nodules. However, tumour size is always a restricting factor for these two techniques, which are unable to detect small HCC in more than 60% of cases.