Diagnostic value of morphological enhancement patterns in the hepatobiliary phase of gadoxetic acid-enhanced MRI to distinguish focal nodular hyperplasia from hepatocellular adenoma

Qualitative and quantitative assessment of gadoxetic acid MRI in distinguishing atypical focal nodular hyperplasia from hepatocellular adenoma subtypes

OBJECTIVE

To assess qualitative and quantitative imaging features, including lesion-to-liver contrast enhancement ratio (LLCER), on gadoxetic acid-enhanced MRI for differentiating atypical focal nodular hyperplasia (aFNH) from hepatocellular adenoma (HCA) subtypes.

MATERIALS AND METHODS

This retrospective study included patients with histopathologically-confirmed aFNH and HCA who underwent gadoxetic acid-enhanced MRI between January 2010 and December 2020. Two radiologists assessed qualitative imaging features and calculated LLCERs for quantitative evaluation of HBP enhancement. Statistical analyses included ROC curves, sensitivity, specificity, and a decision tree.

RESULTS

86 patients (41 ± 11 years; 64 women) had 29 aFNHs and 90 HCAs. HBP iso-/hyperintensity was observed in 72.4% (21/29) of aFNH compared to 28.8% (15/52) of U-HCA, 35% (7/20) of I-HCA, and 0% (0/11) of H-HCA. β-HCA showed 71.4% (5/7) iso-/hyperintensity, overlapping with aFNH (p = 0.17). Homogeneous iso-/hyperintensity and rim-like enhancement were present in 48.3% (14/29) and 20.7% (6/29) of aFNH but absent in β-HCA (p = 0.004). LLCER demonstrated high diagnostic performance, differentiating aFNH from U-HCA, H-HCA, and I-HCA(AUCs 0.91-0.99, sensitivities 82.8-96.6%, specificities 90.0-100%). For β-HCA, LLCER showed overlap with aFNH; AUCs (0.62-0.64) and specificities (57.1%). Among HCAs with HBP iso-/hyperintensity, 74.1% had negative LLCER values, while 25.9% (mostly β-HCA/U-HCA) showed positive values (true enhancement). Combined decision trees selected LLCER as the primary node, with downstream HBP features variably incorporated, except β-HCA, which solely used qualitative features.

CONCLUSION

HBP iso-/hyperintensity and LLCER reliably differentiated aFNH from most HCA subtypes, except β-HCA, validated by decision tree analyses. Homogeneous iso-/hyperintensity or rim-like enhancement was absent in β-HCA, aiding differentiation.

KEY POINTS

Question Variability in hepatobiliary phase (HBP) enhancement among hepatocellular adenoma (HCA) subtypes and atypical FNH (aFNH) poses diagnostic challenges. Findings Despite HBP enhancement overlap in aFNH/β-HCA, "homogeneous" and rim-like enhancement aided aFNH differentiation from HCAs. LLCER separated HCAs lacking true HBP uptake from aFNH. Clinical relevance This study explored challenges in differentiating aFNH from HCA subtypes, especially overlapping β-HCA, highlighting discriminatory qualitative markers and quantitative assessment to distinguish true HBP enhancement, an approach validated by decision tree analysis.

Modified LR-5 criteria based on gadoxetic acid can improve the sensitivity in the diagnosis of hepatocellular carcinoma

BACKGROUND

Currently, only tumors classified as LR-5 are considered definitive hepatocellular carcinoma (HCC), and no further pathologic confirmation is required to initiate therapy. Previous studies have shown that the sensitivity of LR-5 is modest, and lesions enhanced by gadoxetic acid (Gd-EOB-DTPA) may exhibit lower sensitivity than those enhanced by Gd-DTPA.

AIM

To identify malignant ancillary features (AFs) that can independently and significantly predict HCC in Liver Imaging Reporting and Data System version 2018, and to develop modified LR-5 criteria to improve diagnostic performance on Gd-EOB-DTPA - enhanced magnetic resonance imaging.

METHODS

Imaging data from patients with HCC risk factors who underwent abdominal Gd-EOB-DTPA - enhanced magnetic resonance imaging were collected. Univariate and multivariate logistic regression analyses were performed to determine AFs that could independently and significantly predict HCC. The modified LR-5 criteria involved reclassifying LR-4/LR-3 lesions based on major features combined with independently significant AFs for HCC, or by substituting threshold growth with significant AFs. McNemar's test was used to compare the diagnostic performance of the modified LR-5 criteria.

RESULTS

A total of 244 lesions from 216 patients were included. Transitional phase hypointensity, mild - moderate T2 hyperintensity, and fat in mass (more than adjacent liver) were identified as significant independent predictors of HCC. Using the modified LR-5 criteria (e.g., LR-5-M1: LR-4 + transitional phase hypointensity; LR-5-M4: LR-5 by transitional phase hypointensity instead of threshold growth; LR-5-M5: LR-5 by mild - moderate T2 hyperintensity instead of threshold growth; LR-5-M8: LR-3/LR-4 + any two features of transitional phase hypointensity/mild - moderate T2 hyperintensity/fat in mass), sensitivities were significantly increased (88.5%-89.1%) compared to the standard LR-5 (60.6%; all P values < 0.05), while specificities (84.8%-89.9%) remained largely unchanged (93.7%; all P values > 0.05). The LR-5-M8 criterion achieved the highest sensitivity.

CONCLUSION

Mild - moderate T2 hyperintensity, transitional phase hypointensity, and fat in mass are independent and significant predictors of HCC malignant AFs. The modified LR-5 criteria can improve sensitivity without significantly reducing specificity.

Gadoxetic acid-enhanced MRI in differentiating focal nodular hyperplasia from hepatocellular adenoma in children

OBJECTIVE

To investigate the diagnostic performance of gadoxetic acid (Gd-EOB)-enhanced MRI for distinguishing focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA) in children.

METHODS

Twenty-two patients (HCA, n = 6; FNH, n = 16) underwent MRI with Gd-EOB were retrospectively included in this study. The diagnosis was established by biopsy in eight patients and by imaging criteria and follow-up in 13 patients. After qualitative analyses of MRI, quantitative analyses were performed by calculating the relative signal intensity ratios (SIR) between lesion and liver parenchyma both on precontrast and hepatobiliary phase (HBP) images. Two equations, SIRpost-pre and liver-to-lesion contrast enhancement ratio (LLCER), using both SIRs of precontrast and HBP imaging together were also calculated.

RESULTS

The most distinguishing non-contrast-enhanced MRI feature of HCA was intralesional fat since all HCA contained fat but none of FNHs. All FNHs were iso- or hyperintense relative to the adjacent liver on HBP images, but all HCAs except one were hypointense. The mean SIRpost-pre and LLCER of FNH were significantly higher than that of HCA (P < .001). SIRpost-pre and LLCER provided sensitivity and specificity values of 100%.

CONCLUSION

Although intralesional fat is a strong discriminative feature for distinguishing between HCA and FNH, qualitative properties of these lesions may not be enough for confident diagnosis. Gd-EOB uptake in the HBP provides high diagnostic accuracy, but overlap can be seen. SIRpost-pre and LLCER overcome the difficulties and have the best sensitivity and specificity.

ADVANCES IN KNOWLEDGE

Gadoxetic acid-enhanced MRI is a valuable tool for differentiation of FNH and HCA in children.

Lesions hyper- to isointense to surrounding liver in the hepatobiliary phase of gadoxetic acid-enhanced MRI

OBJECTIVES

Hyper- or isointensity in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI has high specificity for focal nodular hyperplasia (FNH) but may be present in hepatocellular adenoma and carcinoma (HCA/HCC). This study aimed to identify imaging characteristics differentiating FNH and HCA/HCC.

MATERIALS AND METHODS

This multicenter retrospective cohort study included patients with pathology-proven FNH or HCA/HCC, hyper-/isointense in the HBP of gadoxetic acid-enhanced MRI between 2010 and 2020. Diagnostic performance of imaging characteristics for the differentiation between FNH and HCA/HCC were reported. Univariable analyses, multivariable logistic regression analyses, and classification and regression tree (CART) analyses were conducted. Sensitivity analyses evaluated imaging characteristics of B-catenin-activated HCA.

RESULTS

In total, 124 patients (mean age 40 years, standard deviation 10 years, 108 female) with 128 hyper-/isointense lesions were included. Pathology diagnoses were FNH and HCA/HCC in 64 lesions (50%) and HCA/HCC in 64 lesions (50%). Imaging characteristics observed exclusively in HCA/HCC were raster and atoll fingerprint patterns in the HBP, sinusoidal dilatation on T2-w, hemosiderin, T1-w in-phase hyperintensity, venous washout, and nodule-in-nodule partification in the HBP and T2-w. Multivariable logistic regression and CART additionally found a T2-w scar indicating FNH, less than 50% fat, and a spherical contour indicating HCA/HCC. In our selected cohort, 14/48 (29%) of HCA were B-catenin activated, most (13/14) showed extensive hyper-/isointensity, and some had a T2-w scar (4/14, 29%).

CONCLUSION

If the aforementioned characteristics typical for HCA/HCC are encountered in lesions extensively hyper- to isointense, further investigation may be warranted to exclude B-catenin-activated HCA.

CLINICAL RELEVANCE

Hyper- or isointensity in the HBP of gadoxetic acid-enhanced MRI is specific for FNH, but HCA/HCC can also exhibit this feature. Therefore, we described imaging patterns to differentiate these entities.

KEY POINTS

FNH and HCA/HCC have similar HBP intensities but have different malignant potentials. Six imaging patterns exclusive to HCA/HCC were identified in this lesion population. These features in liver lesions hyper- to isointense in the HBP warrant further evaluation.

Hepatic focal nodular hyperplasia during follow-up of patients after cyclophosphamide- or oxaliplatin-based chemotherapy: differentiation from liver metastasis

OBJECTIVES

Newly detected hepatic nodules during follow-up of cancer survivors receiving chemotherapy may pose a diagnostic dilemma. We investigated a series of hepatic focal nodular hyperplasia (FNH) diagnosed by either typical MRI features and follow-up or pathology in cancer survivors.

METHODS

This retrospective study evaluated 38 patients with tumours who developed new hepatic FNH after cyclophosphamide-based (n = 19) and oxaliplatin-based (n = 19) chemotherapies. The main tumour types were breast cancer (n = 18) and colorectal cancer (n = 17). MRI findings, clinical features, and temporal evolution of all target hepatic lesions (n = 63) were reported. In addition, the two chemotherapy drug groups were compared.

RESULTS

The median interval between chemotherapy completion and FNH detection was 30.4 months (12.9, 49.4). Six patients underwent biopsy or surgery, while the remaining patients were diagnosed based on typical MRI features and long-term follow-up. Among the patients, 60.5% (23/38) presented with multiple nodules and 63 target lesions were detected. The median size of target lesions was 11.5 mm (8.4, 15.1). The median follow-up time was 32.5 months (21.2, 48.6), and 15 patients experienced changes in their lesions during the follow-up period (11 increased and 4 decreased). The cyclophosphamide-based treatment group had a younger population, a greater proportion of females, and a shorter time to discovery than the oxaliplatin-based chemotherapy group (all p ≤ 0.016).

CONCLUSIONS

FNH may occur in cancer survivors after cyclophosphamide- or oxaliplatin-based chemotherapy. Considering a patient's treatment history and typical MRI findings can help avoid misdiagnosis and unnecessary invasive treatment.

CLINICAL RELEVANCE STATEMENT

When cancer survivors develop new hepatic nodules during follow-up, clinicians should think of the possibility of focal nodular hyperplasia in addition to liver metastasis, especially if the cancer survivors were previously treated with cyclophosphamide or oxaliplatin.

KEY POINTS

Cancer survivors, after chemotherapy, can develop hepatic focal nodular hyperplasia. Cyclophosphamide and oxaliplatin are two chemotherapeutic agents that predispose to focal nodular hyperplasia development. Focal nodular hyperplasia occurs at shorter intervals in patients treated with cyclophosphamide.

Disappearance of Hepatocellular Adenoma in a Patient with Cornelia de Lange Syndrome after Treatment with Transcatheter Arterial Embolization

Cornelia de Lange syndrome (CdLS) is a congenital disorder occasionally associated with congenital portosystemic shunt (CPSS). We herein report a patient with CdLS and CPSS who developed hepatocellular adenomas (HCAs). The patient presented to our hospital for the further investigation of newly diagnosed liver tumors. Imaging findings and pathological examination results indicated that the liver tumors were inflammatory HCAs that subsequently shrank following transcatheter arterial embolization (TAE). Patients with CdLS and CPSS are at risk of developing HCAs, and TAE may be an effective management strategy for HCA in these patients.

Inflammatory Hepatocellular Adenoma Mimicking Focal Nodular Hyperplasia That Grew during Pregnancy and Changed Its Appearance on Magnetic Resonance Imaging after Delivery

We reported a notable case of inflammatory hepatocellular adenoma that grew during pregnancy, consequently changing its appearance on magnetic resonance imaging remarkably. A 5-months-pregnant 35-year-old woman presented with a 37-mm liver nodule that had been diagnosed as focal nodular hyperplasia 3 years earlier. She had never used oral contraceptives. After 2 months, the nodule grew to 57 mm. The patient delivered a full-term infant without complications. Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging performed after delivery revealed markedly different findings compared with the first images. A liver biopsy was performed, and the tumor was diagnosed as inflammatory hepatocellular adenoma.

Update on the Applications of Radiomics in Diagnosis, Staging, and Recurrence of Intrahepatic Cholangiocarcinoma

BACKGROUND

This paper offers an assessment of radiomics tools in the evaluation of intrahepatic cholangiocarcinoma.

METHODS

The PubMed database was searched for papers published in the English language no earlier than October 2022.

RESULTS

We found 236 studies, and 37 satisfied our research criteria. Several studies addressed multidisciplinary topics, especially diagnosis, prognosis, response to therapy, and prediction of staging (TNM) or pathomorphological patterns. In this review, we have covered diagnostic tools developed through machine learning, deep learning, and neural network for the recurrence and prediction of biological characteristics. The majority of the studies were retrospective.

CONCLUSIONS

It is possible to conclude that many performing models have been developed to make differential diagnosis easier for radiologists to predict recurrence and genomic patterns. However, all the studies were retrospective, lacking further external validation in prospective and multicentric cohorts. Furthermore, the radiomics models and the expression of results should be standardized and automatized to be applicable in clinical practice.

β-Catenin-activated inflammatory hepatocellular adenoma with pigmentation and atypical features: a case report

Hepatocellular adenomas are rare diseases, defined as benign liver neoplasms composed of cells with hepatocellular differentiation. Differential diagnosis of hepatocellular adenoma from other lesions, including focal nodular hyperplasia and hepatocellular carcinoma, is crucial to determine treatment strategy. We describe a case of β-catenin-activated inflammatory hepatocellular adenoma with malignant transformation. A 50-year-old man with a suspected liver tumor, based on abdominal ultrasonography findings, was referred to our hospital. Contrast-enhanced computed tomography and magnetic resonance imaging revealed a liver tumor in S2 which was enhanced in the arterial phase to the delayed phase. Based on diagnostic imaging findings, hepatocellular adenoma or focal nodular hyperplasia was suspected. We considered the possibility of malignant potential because of the enlargement of the lesion. Thus, we performed a laparoscopic hepatectomy. Histological examination showed pigment deposition in the hepatocytes, which was determined to be lipofuscin. Mild nuclear swelling and atypia in the tumor area indicated nodular growth. Based on the histological and immunohistochemical findings, the diagnosis was ꞵ-catenin-activated inflammatory hepatocellular adenoma with atypical features. The imaging features of hepatocellular adenoma and focal nodular hyperplasia are similar, but if the tumor tends to grow, surgical treatment should be performed because of the possibility of malignant hepatocellular adenoma.

Long-Term Survival and Curative-Intent Treatment in Hepatitis B or C Virus-Associated Hepatocellular Carcinoma Patients Diagnosed during Screening

Background: We initiated a prospective screening trial in patients with hepatitis to diagnose HCC in the early stage and to evaluate the impact on long-term survival. Methods: From 1993−2006, 10,372 patients with chronic hepatitis B (14%), hepatitis C (81%), or both (5%) were enrolled in an HCC screening program. All patients underwent liver biopsy at enrollment. Transabdominal ultrasonography and serum alpha-fetoprotein were evaluated every 6 months. Abnormal screening results led to axial imaging and tumor biopsy. Results: Cirrhosis was confirmed on biopsy in 2074 patients (20%). HCC was diagnosed in 1016 patients (9.8%), all of whom had cirrhosis (49.0% HCC incidence in patients with cirrhosis). HCC was diagnosed at the initial screening in 165 patients (16.2%) and on follow-up in 851 patients (83.8%). The HCC diagnosis median time during follow-up screening was 6 years (range 4−10). Curative-intent treatment (resection, ablation, or transplant) was performed in 713 patients (70.2%). Overall survival at 5 and 10 years in those 713 patients was 30% and 4%, respectively, compared to no 5-year survivors in the 303 patients with advanced-stage disease (p < 0.001). Cause of death at 5 years in the 713 patients treated with curative intent was HCC in 371 patients (52%), progressive cirrhosis in 116 patients (16%), and other causes in 14 patients (2%). At 10 years, 456 patients (64%) had died from HCC, 171 (24%) from progressive cirrhosis, and 57 (8%) from other causes. Conclusions: Our screening program diagnosed early-stage HCC, permitting curative-intent treatment in 70%, but the 10-year survival rate is 4% due to HCC recurrence and progressive cirrhosis.

Structured Reporting in Radiological Settings: Pitfalls and Perspectives

Objective: The aim of this manuscript is to give an overview of structured reporting in radiological settings. Materials and Method: This article is a narrative review on structured reporting in radiological settings. Particularly, limitations and future perspectives are analyzed. RESULTS: The radiological report is a communication tool for the referring physician and the patients. It was conceived as a free text report (FTR) to allow radiologists to have their own individuality in the description of the radiological findings. However, this form could suffer from content, style, and presentation discrepancies, with a probability of transferring incorrect radiological data. Quality, datafication/quantification, and accessibility represent the three main goals in moving from FTRs to structured reports (SRs). In fact, the quality is related to standardization, which aims to improve communication and clarification. Moreover, a “structured” checklist, which allows all the fundamental items for a particular radiological study to be reported and permits the connection of the radiological data with clinical features, allowing a personalized medicine. With regard to accessibility, since radiological reports can be considered a source of research data, SR allows data mining to obtain new biomarkers and to help the development of new application domains, especially in the field of radiomics. Conclusions: Structured reporting could eliminate radiologist individuality, allowing a standardized approach.

Multimodality Imaging Assessment of Desmoid Tumors: The Great Mime in the Era of Multidisciplinary Teams

Desmoid tumors (DTs), also known as desmoid fibromatosis or aggressive fibromatosis, are rare, locally invasive, non-metastatic soft tissue tumors. Although histological results represent the gold standard diagnosis, imaging represents the fundamental tool for the diagnosis of these tumors. Although histological analysis represents the gold standard for diagnosis, imaging represents the fundamental tool for the diagnosis of these tumors. DTs represent a challenge for the radiologist, being able to mimic different pathological conditions. A proper diagnosis is required to establish an adequate therapeutic approach. Multimodality imaging, including ultrasound (US), computed tomography (CT) and Magnetic Resonance Imaging (MRI), should be preferred. Different imaging techniques can also guide minimally invasive treatments and monitor their effectiveness. The purpose of this review is to describe the state-of-the-art multidisciplinary imaging of DTs; and its role in patient management.

A Narrative Review on LI-RADS Algorithm in Liver Tumors: Prospects and Pitfalls

Liver cancer is the sixth most detected tumor and the third leading cause of tumor death worldwide. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with specific risk factors and a targeted population. Imaging plays a major role in the management of HCC from screening to post-therapy follow-up. In order to optimize the diagnostic-therapeutic management and using a universal report, which allows more effective communication among the multidisciplinary team, several classification systems have been proposed over time, and LI-RADS is the most utilized. Currently, LI-RADS comprises four algorithms addressing screening and surveillance, diagnosis on computed tomography (CT)/magnetic resonance imaging (MRI), diagnosis on contrast-enhanced ultrasound (CEUS) and treatment response on CT/MRI. The algorithm allows guiding the radiologist through a stepwise process of assigning a category to a liver observation, recognizing both major and ancillary features. This process allows for characterizing liver lesions and assessing treatment. In this review, we highlighted both major and ancillary features that could define HCC. The distinctive dynamic vascular pattern of arterial hyperenhancement followed by washout in the portal-venous phase is the key hallmark of HCC, with a specificity value close to 100%. However, the sensitivity value of these combined criteria is inadequate. Recent evidence has proven that liver-specific contrast could be an important tool not only in increasing sensitivity but also in diagnosis as a major criterion. Although LI-RADS emerges as an essential instrument to support the management of liver tumors, still many improvements are needed to overcome the current limitations. In particular, features that may clearly distinguish HCC from cholangiocarcinoma (CCA) and combined HCC-CCA lesions and the assessment after locoregional radiation-based therapy are still fields of research.

Combined Hepatocellular-Cholangiocarcinoma: What the Multidisciplinary Team Should Know

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare type of primary liver malignancy. Among the risk factors, hepatitis B and hepatitis C virus infections, cirrhosis, and male gender are widely reported. The clinical appearance of cHCC-CCA is similar to that of HCC and iCCA and it is usually silent until advanced states, causing a delay of diagnosis. Diagnosis is mainly based on histology from biopsies or surgical specimens. Correct pre-surgical diagnosis during imaging studies is very problematic and is due to the heterogeneous characteristics of the lesion in imaging, with overlapping features of HCC and CCA. The predominant histological subtype within the lesion establishes the predominant imaging findings. Therefore, in this scenario, the radiological findings characteristic of HCC show an overlap with those of CCA. Since cHCC-CCAs are prevalent in patients at high risk of HCC and there is a risk that these may mimic HCC, it is currently difficult to see a non-invasive diagnosis of HCC. Surgery is the only curative treatment of HCC-CCA. The role of liver transplantation (LT) in the treatment of cHCC-CCA remains controversial, as is the role of ablative or systemic therapies in the treatment of this tumour. These lesions still remain challenging, both in diagnosis and in the treatment phase. Therefore, a pre-treatment imaging diagnosis is essential, as well as the identification of prognostic factors that could stratify the risk of recurrence and the most adequate therapy according to patient characteristics.

Advanced Magnetic Resonance Imaging (MRI) Techniques: Technical Principles and Applications in Nanomedicine

Simple Summary

Magnetic Resonance Imaging (MRI) is a consolidated imaging tool for the multiparametric assessment of tissues in various pathologies from degenerative and inflammatory diseases to cancer. In recent years, the continuous technological evolution of the equipment has led to the development of sequences that provide not only anatomical but also functional and metabolic information. In addition, there is a growing and emerging field of research in clinical applications using MRI to exploit the diagnostic and therapeutic capabilities of nanocompounds. This review illustrates the application of the most advanced magnetic resonance techniques in the field of nanomedicine.

Abstract

In the last decades, nanotechnology has been used in a wide range of biomedical applications, both diagnostic and therapeutic. In this scenario, imaging techniques represent a fundamental tool to obtain information about the properties of nanoconstructs and their interactions with the biological environment in preclinical and clinical settings. This paper reviews the state of the art of the application of magnetic resonance imaging in the field of nanomedicine, as well as the use of nanoparticles as diagnostic and therapeutic tools, especially in cancer, including the characteristics that hinder the use of nanoparticles in clinical practice.

Comparison of the Value of Color Doppler Ultrasound and Multislice Spiral CT in the Differential Diagnosis of Benign and Malignant Nodules in the Liver

Objective

This study aimed to explore the value of color Doppler ultrasound and multislice spiral CT (MSCT) in the differential diagnosis of benign and malignant nodules in the liver.

Methods

The clinical imaging data of 102 patients with nodular hepatocellular carcinoma (hepatocellular carcinoma group) and 50 patients with focal nodular hyperplasia (FNH) of the liver (FNH group) admitted to our hospital were collected, and their color Doppler ultrasound and MSCT imaging features were retrospectively analyzed to explore the value of their clinical application in the differential diagnosis of benign and malignant nodules in the liver.

Results

The sensitivity, accuracy, and negative predictive value of MSCT in the diagnosis of nodular liver cancer were 94.12%, 92.76%, and 88.24%, respectively, which were significantly higher than those of color Doppler ultrasound 79.41%, 84.21%, and 69.12%, and the difference was statistically significant (P < 0.05).

Conclusion

In conclusion, the value of MSCT in the differential diagnosis of benign and malignant liver nodules was significantly better than color Doppler ultrasound.

Morphological, dynamic and functional characteristics of liver pseudolesions and benign lesions

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide and one of the most common causes of death among patients with cirrhosis, developing in 1-8% of them every year, regardless of their cirrhotic stage. The radiological features of HCC are almost always sufficient for reaching the diagnosis; thus, histological confirmation is rarely needed. However, the study of cirrhotic livers remains a challenge for radiologists due to the developing of fibrous and regenerative tissue that cause the distortion of normal liver parenchyma, changing the typical appearances of benign lesions and pseudolesions, which therefore may be misinterpreted as malignancies. In addition, a correct distinction between pseudolesions and malignancy is crucial to allow appropriate targeted therapy and avoid treatment delays.The present review encompasses technical pitfalls and describes focal benign lesions and pseudolesions that may be misinterpreted as HCC in cirrhotic livers, providing the imaging features of regenerative nodules, large regenerative nodules, siderotic nodules, hepatic hemangiomas (including rapidly filling and sclerosed hemangiomas), segmental hyperplasia, arterioportal shunts, focal confluent fibrosis and focal fatty changes. Lastly, the present review explores the most promising new imaging techniques that are emerging and that could help radiologists differentiate benign lesions and pseudolesions from overt HCC.