Multiphasic MDCT enhancement pattern of hepatocellular carcinoma smaller than 3 cm in diameter: tumor size and cellular differentiation. AJR Am J Roentgenol. 2009;193:W482-W489. [PMID: 19933622 DOI: 10.2214/ajr.08.1818]

CT-based radiomics for predicting pathological grade in hepatocellular carcinoma

Objective

To construct and validate radiomics models for hepatocellular carcinoma (HCC) grade predictions based on contrast-enhanced CT (CECT).

Methods

Patients with pathologically confirmed HCC after surgery and underwent CECT at our institution between January 2016 and December 2020 were enrolled and randomly divided into training and validation datasets. With tumor segmentation and feature extraction, radiomic models were constructed using univariate analysis, followed by least absolute shrinkage and selection operator (LASSO) regression. In addition, combined models with clinical factors and radiomics scores (Radscore) were constructed using logistic regression. Finally, all models were evaluated using the receiver operating characteristic (ROC) curve with the area under the curve (AUC), calibration curve, and decision curve analysis (DCA).

Results

In total 242 patients were enrolled in this study, of whom 170 and 72 formed the training and validation datasets, respectively. The arterial phase and portal venous phase (AP+VP) radiomics model were evaluated as the best for predicting HCC pathological grade among all the models built in our study (AUC = 0.981 in the training dataset; AUC = 0.842 in the validation dataset) and was used to build a nomogram. Furthermore, the calibration curve and DCA indicated that the AP+VP radiomics model had a satisfactory prediction efficiency.

Conclusions

Low- and high-grade HCC can be distinguished with good diagnostic performance using a CECT-based radiomics model.

Analysis of clinicopathologic and imaging features of dual-phenotype hepatocellular carcinoma

Dual-phenotype hepatocellular carcinoma (DPHCC) is a new subtype of hepatocellular carcinoma (HCC). This study aimed to investigate the relationship between the computerized tomography scan (CT) imaging and clinicopathologic features of DPHCC. The CT imaging and clinicopathologic data of 97 HCC cases who underwent radical resection were collected retrospectively. The CT imaging feature was evaluated by the ratio of the average CT value of tumor to liver (TLR) in the plain scan, arterial, portal vein and delayed phases. The association between CT imaging and clinicopathologic features was analyzed using the t-test or chi-square test. Univariate and multivariate recurrence-free survival (RFS) analysis and overall survival (OS) were performed. The positive rates of cytokeratin 7 (CK7) and CK19 were 35.1% and 20.6% respectively. The positive rate of CK19 was significantly higher in cases with age < 47 years (P = 0.005), tumor diameter > 4 cm (P = 0.016) or AFP ≥ 400 ng/ml (P = 0.007). The TLR in the portal vein phase was significantly lower in CK19 positive group (P = 0.024). The recurrence risk was significantly higher in cases with CK19 positive (HR: 2.17, 95% CI 1.16 to 4.04, P = 0.013), tumor diameter > 4 cm (HR: 2.05, 95% CI 1.11 to 3.78, P = 0.019), AFP ≥ 400 ng/ml (HR: 2.50, 95% CI 1.37 to 4.54, P = 0.002) or CA199 ≥ 37 U/ml (HR: 2.23, 95% CI 1.12 to 4.42, P = 0.020). However, imaging features, pathological subtype, CK7 or CK19 expression were not significantly related to HCC OS in the univariate and multivariate analysis (all P > 0.05). The expression of CK19 may be associated with the enhancement feature of the portal vein phase CT image, and CK19 positive may suggest a worse RFS.

LI-RADS threshold growth based on tumor growth rate can improve the diagnosis of hepatocellular carcinoma ≤ 3.0 cm

OBJECTIVE

Despite the revision of threshold growth (TG) in the Liver Imaging Reporting and Data System (LI-RADS) version 2018, the appropriate time period between the two examinations for TG has not been determined. We compared the accuracy of LI-RADS with TG based on tumor growth rate for the diagnosis of hepatocellular carcinoma (HCC) with that of LI-RADS v2018 based on the original TG.

METHODS

Patients who underwent preoperative MRI for focal solid lesions (≤ 3.0 cm) were retrospectively evaluated. Three readers measured the size of each lesion on prior CT/MRI and index MRI, with tumor growth rate defined as the percent change in lesion size per month. In addition to the original TG (≥ 50% size increase within ≤ 6 months), the modified TG based on tumor growth rates ≥ 10%/month (TG-10%), ≥ 20%/month (TG-20%), and ≥ 30%/month (TG-30%) were evaluated. The accuracies of these evaluation methods for LI-RADS category 5 HCC were compared using generalized estimation equations.

RESULTS

A total of 508 lesions from 370 patients were evaluated. Compared with LI-RADS v2018 with the original TG, the accuracy of LI-RADS with TG-10% was significantly higher (85.0% vs. 80.7%, p < .001), whereas the accuracies of LI-RADS with TG-20% (81.3% vs. 80.7%, p = .404) and TG-30% (79.3% vs. 80.7%, p = .052) were not significant. The sensitivity of LI-RADS with TG-10% was higher than that of LI-RADS v2018 (79.0% vs. 72.5%, p < .001), whereas their specificities were not significantly different (96.6% vs. 96.6%, p > .999).

CONCLUSION

TG-10% improved the sensitivity of LI-RADS by detecting additional hepatocellular carcinomas underestimated due to short-term follow-up.

CLINICAL RELEVANCE STATEMENT

Threshold growth based on tumor growth rate can be clinically useful in the diagnosis of hepatocellular carcinoma, by improving the sensitivity of LI-RADS.

KEY POINTS

• The diagnostic accuracy of Liver Imaging Reporting and Data System (LI-RADS) v2018 was not significantly affected by the time interval between prior and index assessments of threshold growth. • In the 334 hepatocellular carcinomas, the frequency of threshold growth was significantly higher using tumor growth rate ≥ 10%/month (TG-10%) than original threshold growth (53.3% vs. 18.0%, p < .001). • Compared with LI-RADS v2018 with the original threshold growth, LI-RADS with TG-10% had significantly higher accuracy (85.0% vs. 80.7%, p < .001) and sensitivity (79.0% vs. 72.5%, p < .001) but a similar specificity (96.6% vs. 96.6%, p > .999).

Computed tomographic manifestations of celiac ganglia between hypertensive and non-hypertensive population

The celiac ganglion (CG) is associated with the sympathetic nervous system (SNS) and plays an important role in the pathogenesis of hypertension. The characteristics of the CG in patients with hypertension remain unknown. The aim of our study was to explore the differences in celiac ganglia (CGs) characteristics between hypertensive and non-hypertensive populations using computed tomography (CT). CGs manifestations on multidetector row CT in 1003 patients with and without hypertension were retrospectively analyzed. The morphological characteristics and CT values of the left CGs were recorded. The CT values of the ipsilateral adrenal gland (AG) and crus of the diaphragm (CD) were also measured. The left CG was located between the left AG and CD, and most CGs were long strips. The frequency of visualization of the left CGs was higher in the hypertension group than in the non-hypertension group (p < .05). There were no significant differences in the maximum diameter, size, and shape ratio of the left CGs between the two groups (p > .05). Except for the left CG in the arterial phase, the CT values of the left CG and AG in the non-hypertensive group were higher than those in the hypertension group (p < .05). The venous phase enhancement of the left CG in the non-hypertension group was significantly higher than that in the hypertension group (p < .05). Our findings reveal that CGs have characteristic manifestations in the hypertensive population. As important targets of the SNS, CGs have the potential to regulate blood pressure.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Current Imaging Diagnosis of Hepatocellular Carcinoma

Simple Summary

The role of imaging in the management of hepatocellular carcinoma (HCC) has significantly evolved and expanded beyond the plain radiological confirmation of the tumor based on the typical appearance in a multiphase contrast-enhanced CT or MRI examination. The introduction of hepatobiliary contrast agents has enabled the diagnosis of hepatocarcinogenesis at earlier stages, while the application of ultrasound contrast agents has drastically upgraded the role of ultrasound in the diagnostic algorithms. Newer quantitative techniques assessing blood perfusion on CT and MRI not only allow earlier diagnosis and confident differentiation from other lesions, but they also provide biomarkers for the evaluation of treatment response. As distinct HCC subtypes are identified, their correlation with specific imaging features holds great promise for estimating tumor aggressiveness and prognosis. This review presents the current role of imaging and underlines its critical role in the successful management of patients with HCC.

Abstract

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer related death worldwide. Radiology has traditionally played a central role in HCC management, ranging from screening of high-risk patients to non-invasive diagnosis, as well as the evaluation of treatment response and post-treatment follow-up. From liver ultrasonography with or without contrast to dynamic multiple phased CT and dynamic MRI with diffusion protocols, great progress has been achieved in the last decade. Throughout the last few years, pathological, biological, genetic, and immune-chemical analyses have revealed several tumoral subtypes with diverse biological behavior, highlighting the need for the re-evaluation of established radiological methods. Considering these changes, novel methods that provide functional and quantitative parameters in addition to morphological information are increasingly incorporated into modern diagnostic protocols for HCC. In this way, differential diagnosis became even more challenging throughout the last few years. Use of liver specific contrast agents, as well as CT/MRI perfusion techniques, seem to not only allow earlier detection and more accurate characterization of HCC lesions, but also make it possible to predict response to treatment and survival. Nevertheless, several limitations and technical considerations still exist. This review will describe and discuss all these imaging modalities and their advances in the imaging of HCC lesions in cirrhotic and non-cirrhotic livers. Sensitivity and specificity rates, method limitations, and technical considerations will be discussed.

Safety of percutaneous, image-guided biopsy of hepatocellular carcinoma with and without concurrent ablation

PURPOSE

To determine the prevalence of adverse events after image-guided biopsy of histologically proven hepatocellular carcinomas (HCC) using a standardized, indirect access, coaxial biopsy technique.

METHODS

In this IRB-approved, HIPAA compliant, and retrospective study, we evaluated all consecutive adult patients from 2011 to 2016 who underwent image-guided biopsy of HCC with and without concurrent ablation. Tumor seeding was defined as any new lesion along the needle tract on subsequent imaging. Adverse events were graded using both the Clavien-Dindo Complication Classification system and the most recently proposed Society of Interventional Radiology (SIR) Adverse Event Classification System.

RESULTS

A total of 383 patients underwent 398 biopsies (64 ± 11 years; 112 women, 271 men). Most patients (282; 71%) underwent concurrent ablation. Adverse events occurred after 18 biopsies (4.5%): 13 were Grade I (Clavien-Dindo) or minor (SIR) and included hematoma (7), hepatic vein thrombus (2), portal vein thrombus (2), moderate pleural effusion (1), and small pneumothorax (1). The remaining 5 (1.3%) adverse events were classified as Grade II-IIIa (Clavien-Dindo) or moderate (SIR) and included hematoma requiring blood products (n = 1), arrhythmia (n = 1), and symptomatic pleural effusions requiring treatment (n = 3). Baseline age, sex, cause of liver disease, HCC diameter, and HCC grade were not associated with adverse events. There were no tumor seeding events after a median follow-up of 611 days (interquartile range of 211-1104).

CONCLUSION

Percutaneous image-guided tissue sampling using a standardized, indirect access, coaxial technique can be performed safely with and without concurrent ablation by trained cross-sectional interventional radiologists at a tertiary liver transplant center.

Quantitative washout in patients with hepatocellular carcinoma undergoing TACE: an imaging biomarker for predicting prognosis?

BACKGROUND

The delayed percentage attenuation ratio (DPAR) was recently identified as a novel predictor of an early complete response in patients with hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE). In this study, we aimed to validate the role of DPAR as a predictive biomarker for short-, mid-, and long-term outcomes after TACE.

METHODS

We retrospectively reviewed laboratory and imaging data for 103 treatment-naïve patients undergoing initial TACE treatment at our tertiary care center between January 2016 and November 2020. DPAR and other washin and washout indices were quantified in the triphasic computed tomography performed before the initial TACE. The correlation of DPAR and radiologic response was investigated. Furthermore, the influence of DPAR on the 6-, 12-, 18-, and 24-month survival rates and the median overall survival (OS) was compared to other established washout indices and estimates of tumor burden and remnant liver function.

RESULTS

The DPAR was significantly of the target lesions (TLs) with objective response to TACE after the initial TACE session was significantly higher compared to patients with stable disease (SD) or progressive disease (PD) (125 (IQR 118-134) vs 110 (IQR 103-116), p < 0.001). Furthermore, the DPAR was significantly higher in patients who survived the first 6 months after TACE (122 vs. 115, p = 0.04). In addition, the number of patients with a DPAR > 120 was significantly higher in this group (n = 38 vs. n = 8; p = 0.03). However, no significant differences were observed in the 12-, 18-, and 24-month survival rates after the initial TACE. Regarding the median OS, no significant difference was observed for patients with a high DPAR compared to those with a low DPAR (18.7 months vs. 12.7 months, p = 0.260).

CONCLUSIONS

Our results confirm DPAR as the most relevant washout index for predicting the short-term outcome of patients with HCC undergoing TACE. However, DPAR and the other washout indices were not predictive of mid- and long-term outcomes.

Tumor attenuation and quantitative analysis of perfusion parameters derived from tri-phasic CT scans in hepatocellular carcinoma: Relationship with histological grade

The aim of the current study was to explore the value of tumor attenuation and quantitative analysis of perfusion parameters obtained from traditional tri-phasic CT scans in grading hepatocellular carcinoma (HCC).Totally 39 patients (42 lesion samples) with pathologically confirmed HCC who underwent tri-phasic CT scans were enrolled. HCC lesions were divided into non-poorly differentiated HCC (NP-HCC; n = 31) and poorly differentiated HCC (pHCC; n = 11). All lesions were divided into 5 groups according to the attenuation on different CT enhancement phase. The values of tumor attenuation on different scanning phases were measured. The following parameters were calculated: arterial enhancement fraction (AEF), portal venous supply coefficient (PVC), and hepatic arterial supply coefficient (HAC). The relationship of perfusion parameters with the histological grade of HCC was analyzed. Receiver operating characteristic curves were generated.No significant correlation was observed between the perfusion parameters and tumor grading. Only HAC showed a non-significant trend in different grades of HCC (pHCC < NP-HCC; P = .07). The pHCC cases had significantly decreased values of tumor attenuation on the unenhanced phase (TAu), tumor attenuation on the portal phase portal phase (TAp), and equilibrium phase (TAe) (P < .01). The difference of tumor attenuation between the portal phase and the unenhanced phase (TAp-TAu) of the pHCC cases was decreased than that of the NP-HCC cases (P < .01), whereas the difference of attenuation between the equilibrium phase and portal phase (TAe-TAp) was significantly higher in the pHCC cases than that in the NP-HCC cases (P < .01). TAe-TAp had the highest area under the curve. The number of tumor enhancement pattern in Group 5 of HCCs with a diameter of 3 cm or more was significantly more than that of HCCs with a diameter of less than 3 cm or with other different enhancement patterns (P < .01).Histological HCC grading cannot be predicted by the perfusion parameters derived from traditional tri-phasic CT scans, whereas the tumor attenuation on different phases and the tumor attenuation differences among different phases, especially the mean value of TAe-TAp, might be useful for non-invasive prediction on the degree of HCC differentiation.

Assessment of factors affecting washout appearance of hepatocellular carcinoma on CT

OBJECTIVES

To identify independent imaging and histopathologic factors that affect washout appearance of hepatocellular carcinoma (HCC) in CT images.

METHODS

This retrospective study included 264 patients who had undergone surgical resection for treatment-naïve single HCC between January 2014 and December 2015 and had available preoperative multiphasic CT images. Two reviewers evaluated the CT imaging features of HCC using LI-RADS v2018. The "washout" was visually assessed in portal venous or equilibrium phases. Depending on the presence of washout appearance of HCC, all patients were divided into "washout" (n = 228) and "no washout" (n = 36) groups. Multivariable logistic regression analysis was used to identify factors associated with the absence of washout appearance of HCC.

RESULTS

A total of 264 HCCs (median size, 2.6 cm) were analyzed. Histologically proven hepatic steatosis (macrovesicular steatosis ≥ 5%) (odds ratio [OR], 2.65; 95% confidence interval [CI], 1.05-6.74; p = 0.040), tumor capsule on histopathology (OR, 0.17; 95% CI, 0.06-0.50; p = 0.001), and mosaic appearance on CT image (OR, 0.34; 95% CI, 0.14-0.85; p = 0.021) were independent factors associated with the absence of washout appearance of HCC. In 189 patients with available unenhanced CT images, CT-diagnosed hepatic steatosis was also an independent factor for the absence of washout appearance of HCC (OR, 9.26; 95% CI, 3.06-28.02; p < 0.001).

CONCLUSIONS

Washout appearance of HCC in CT images could be obscured in both histologically proven hepatic steatosis and CT-diagnosed hepatic steatosis, and could be enhanced with tumor capsule on histopathology and mosaic appearance on CT image.

KEY POINTS

• Hepatic steatosis is an independent factor related to the absence of washout appearance of hepatocellular carcinoma in CT images, in both histologically proven hepatic steatosis and CT-diagnosed hepatic steatosis. • Both histologically proven hepatic steatosis and CT-diagnosed hepatic steatosis have higher odds of absence of washout appearance of hepatocellular carcinoma compared to non-steatotic liver. • Tumor capsule on histopathology and mosaic appearance on CT image are independent factors that enhance the probability that washout appearance of hepatocellular carcinoma is visible.

Quantitative assessment of HCC wash-out on CT is a predictor of early complete response to TACE

OBJECTIVES

To investigate the predictive value of four-phase contrast-enhanced CT (CECT) for early complete response (CR) to drug-eluting-bead transarterial chemoembolization (DEB-TACE), with a particular focus on the quantitatively assessed wash-in and wash-out.

METHODS

A retrospective analysis of preprocedural CECTs was performed for 129 HCC nodules consecutively subjected to DEB-TACE as first-line therapy. Lesion size, location, and margins were recorded. For the quantitative analysis, the following parameters were computed: contrast enhancement ratio (CER) and lesion-to-liver contrast ratio (LLC) as estimates of wash-in; absolute and relative wash-out (WO_abs and WO_rel) and delayed percentage attenuation ratio (DPAR) as estimates of wash-out. The early radiological response of each lesion was assessed by the mRECIST criteria and dichotomized in CR versus others (partial response, stable disease, and progressive disease).

RESULTS

All quantitatively assessed wash-out variables had significantly higher rates for CR lesions (WO_abs p = 0.01, WO_rel p = 0.01, and DPAR p = 0.00002). However, only DPAR demonstrated an acceptable discriminating ability, quantified by AUC = 0.80 (95% CI0.73-0.88). In particular, nodules with DPAR ≥ 120 showed an odds ratio of 3.3(1.5-7.2) for CR (p = 0.0026). When accompanied by smooth lesion margins, DPAR ≥ 120 lesions showed a 78% CR rate at first follow-up imaging. No significative association with CR was found for quantitative wash-in estimates (CER and LLC).

CONCLUSIONS

Based on preprocedural CECT, the quantitative assessment of HCC wash-out is useful in predicting early CR after DEB-TACE. Among the different formulas for wash-out quantification, DPAR has the best discriminating ability. When associated, DPAR ≥ 120 and smooth lesion margins are related to relatively high CR rates.

KEY POINTS

• A high wash-out rate, quantitatively assessed during preprocedural four-phase contrast-enhanced CT (CECT), is a favorable predictor for early radiological complete response of HCC to drug-eluting-bead chemoembolization (DEB-TACE). • The arterial phase of CECT shows great dispersion of attenuation values among different lesions, even when a standardized protocol is used, limiting its usefulness for quantitative analyses. • Among the different formulas used to quantify the wash-out rate (absolute wash-out, relative wash-out, and delayed percentage attenuation ratio), the latter (DPAR), based only on the delayed phase, is the most predictive (AUC = 0.80), showing a significant association with complete response for values above 120.

Imaging-based diagnosis of benign lesions and pseudolesions in the cirrhotic liver

Liver cirrhosis is a leading cause of death worldwide, with 1-year mortality rates of up to 57% in decompensated patients. Hepatocellular carcinoma (HCC) is the most common primary tumor in cirrhotic livers and the second leading cause of cancer-related mortality worldwide. Annually, up to 8% of patients with cirrhosis develop HCC. The diagnosis of HCC rarely requires histological confirmation: in fact, according to the most recent guidelines, the imaging features of HCC are almost always sufficient for a certain diagnosis. Thus, the role of the radiologist is pivotal because the accurate detection and characterization of focal liver lesions in patients with cirrhosis are essential in improving clinical outcomes. Despite recent technical innovations in liver imaging, several issues remain for radiologists regarding the differentiation of HCC from other hepatic lesions, particularly benign lesions and pseudolesions. It is important to avoid misdiagnosis of benign liver lesions as HCC (false-positive cases) because this diagnostic misinterpretation may lead to ineligibility of a patient for potentially curative treatments or inappropriate assignment of high priority scores to patients on waiting lists for liver transplantation. This review presents a pocket guide that could be useful for the radiologist in the diagnosis of benign lesions and pseudolesions in cirrhotic livers, highlighting the imaging features that help in making the correct diagnosis of macroregenerative nodules; siderotic nodules; arterioportal shunts; hemangiomas, including fast-filling hemangiomas, hemangiomas with pseudowashout, and sclerosed hemangiomas; confluent fibrosis; pseudomasses in chronic portal vein thrombosis; and focal fatty changes.

Intra-individual comparison of dual portal venous phases for non-invasive diagnosis of hepatocellular carcinoma at gadoxetic acid-enhanced liver MRI

OBJECTIVES

To compare the diagnostic performances of first and second portal venous phases (PVP1 and PVP2) in revealing washout and capsule appearance for non-invasive HCC diagnoses in gadoxetic acid-enhanced MRI (Gd-EOB-MRI).

METHODS

This retrospective study included 123 at-risk patients with 160 hepatic observations (HCCs, n = 116; non-HCC malignancies, n = 18; benign, n = 26) showing arterial phase hyper-enhancement (APHE) ≥ 1 cm at Gd-EOB-MRI. The mean time intervals from gadoxetic acid injection to PVP1 and PVP2 acquisitions were 53 ± 2 s and 73 ± 3 s, respectively. After evaluating image findings independently, imaging findings and diagnoses were finalized by a consensus of two radiologists using either PVP1 or PVP2 image sets according to the LI-RADS v2018 or EASL criteria. Sensitivity, specificity, and accuracy were compared.

RESULTS

Among HCCs, more washout and enhancing capsule were observed in PVP2 (83.6% and 27.6%) than in PVP1 (50.9% and 19.8%) (p < 0.001, both). The PVP2 set presented significantly higher sensitivity (83.6% vs. 53.5%, LI-RADS; 82.8% vs. 50.0%, EASL; p < 0.001, both) and accuracy (0.88 vs. 0.73, LI-RADS; 0.88 vs. 0.72, EASL; p < 0.001, both) than the PVP1 set without significant specificity loss (93.2% vs. 93.2%, by LI-RADS or EASL; p = 0.32, both). None of the non-HCC malignancy was non-invasively diagnosed as HCC in both PVP image sets.

CONCLUSION

Late acquisition of PVP detected washout and enhancing capsule of HCC more sensitively than early acquisition, enabling accurate diagnoses of HCC, according to LI-RADS or EASL criteria.

KEY POINTS

• Among HCCs, more washout and enhancing capsules were observed in PVP2 than PVP1, quantitatively and qualitatively. • The portal venous phase acquired at around 70 s after contrast media administration (PVP2) provided significantly higher sensitivity and AUC value than PVP1 by using LI-RADS v2018 or EASL criteria. • More HCCs were categorized as LR-5 in PVP2 than in PVP1 images, and the specificity of PVP2 (93.5%) was comparable with PVP1 (93.5%).

Hepatocellular carcinoma in non-cirrhotic versus cirrhotic liver: a clinico-radiological comparative analysis

AIM

To compare clinico-radiological pattern of non-cirrhotic versus cirrhotic HCC and correlate them with histopathological tumor grade.

MATERIALS AND METHODS

This prospective study was carried out on 94 patients enrolled following ultrasound diagnosis of a liver mass measuring > 3 cm. Multiphasic MDCT was performed on all treatment-naïve cases and 56 cases with imaging pattern consistent with unifocal HCC were selected. Background liver parenchyma was assessed on ultrasound for cirrhosis and NAFLD. Cases were categorized into cirrhotic liver (CL) and non-cirrhotic liver (NCL) groups with 26 and 30 cases, respectively, and guided biopsy of each liver mass was performed. AFP levels were compared in both groups. Serum markers for hepatitis B and C were assessed. Masses in both groups were compared for morphology, attenuation on each phase and washout time. Presence of capsule, corona enhancement, satellite nodules and portal vein invasion was noted.

RESULTS

AFP level was higher in CL group. HBV serum marker was raised in both groups. Most HCCs in NCL were moderately differentiated (histopathology), larger, had well-defined margins, showed mosaic pattern of enhancement, complete capsule and delayed phase washout. Majority in CL group were poorly differentiated, smaller, had ill-defined margins, showed heterogeneous enhancement, absent capsule and portal venous phase washout. Time of washout correlated with histopathological differentiation of masses, with earlier washout indicating poorer differentiation.

CONCLUSION

HCCs in NCL have different clinico-radiological characteristics than HCCs in CL. Time of contrast washout correlates with histopathological grade of HCC. Non-cirrhotic NAFLD may require formulation of new screening guidelines for HCC.

Atypical Appearance of Hepatocellular Carcinoma and Its Mimickers: How to Solve Challenging Cases Using Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging

Hepatocellular carcinoma (HCC) can be diagnosed noninvasively with contrast-enhanced dynamic computed tomography, magnetic resonance imaging, or ultrasonography on the basis of its hallmark imaging features of arterial phase hyperenhancement and washout on portal or delayed phase images. However, approximately 40% of HCCs show atypical imaging features, posing a significant diagnostic challenge for radiologists. Another challenge for radiologists in clinical practice is the presentation of many HCC mimickers such as intrahepatic cholangiocarcinoma, combined HCC-cholangiocarcinoma, arterioportal shunt, and hemangioma in the cirrhotic liver. The differentiation of HCCs from these mimickers on preoperative imaging studies is of critical importance. Hence, we will review the typical and atypical imaging features of HCCs and the imaging features of its common mimickers. In addition, we will discuss how to solve these challenges in practice.

Angiogenesis in Hepatocellular Carcinoma; Pathophysiology, Targeted Therapy, and Role of Imaging

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide, usually occurring on a background of liver cirrhosis. HCC is a highly vascular tumor in which angiogenesis plays a major role in tumor growth and spread. Tumor-induced angiogenesis is usually related to a complex interplay between multiple factors and pathways, with vascular endothelial growth factor being a major player in angiogenesis. In the past decade, understanding of tumor-induced angiogenesis has led to the emergence of novel anti-angiogenic therapies, which act by reducing neo-angiogenesis, and improving patient survival. Currently, Sorafenib and Lenvatinib are being used as the first-line treatment for advanced unresectable HCC. However, a disadvantage of these agents is the presence of numerous side effects. A major challenge in the management of HCC patients being treated with anti-angiogenic therapy is effective monitoring of treatment response, which decides whether to continue treatment or to seek second-line treatment. Several criteria can be used to assess response to treatment, such as quantitative perfusion on cross-sectional imaging and novel/emerging MRI techniques, including a host of known and emerging biomarkers and radiogenomics. This review addresses the pathophysiology of angiogenesis in HCC, accurate imaging assessment of angiogenesis, monitoring effects of anti-angiogenic therapy to guide future treatment and assessing prognosis.

2018 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer globally and the fourth most common cancer in men in Korea, where the prevalence of chronic hepatitis B infection is high in middle-aged and elderly patients. These practice guidelines will provide useful and constructive advice for the clinical management of patients with HCC. A total of 44 experts in hepatology, oncology, surgery, radiology, and radiation oncology in the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2014 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions.

2018 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer globally and the fourth most common cancer in men in Korea, where the prevalence of chronic hepatitis B infection is high in middle-aged and elderly patients. These practice guidelines will provide useful and constructive advice for the clinical management of patients with HCC. A total of 44 experts in hepatology, oncology, surgery, radiology and radiation oncology in the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2014 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions.

MR with Gd-EOB-DTPA in assessment of liver nodules in cirrhotic patients

To date the imaging diagnosis of liver lesions is based mainly on the identification of vascular features, which are typical of overt hepatocellular carcinoma (HCC), but the hepatocarcinogenesis is a complex and multistep event during which, a spectrum of nodules develop within the liver parenchyma, including benign small and large regenerative nodule (RN), low-grade dysplastic nodule (LGDN), high-grade dysplastic nodule (HGDN), early HCC, and well differentiated HCC. These nodules may be characterised not only on the basis of their respective different blood supplies, but also on their different hepatocyte function. Recently, in liver imaging the introduction of hepatobiliary magnetic resonance imaging contrast agent offered the clinicians the possibility to obtain, at once, information not only related to the vascular changes of liver nodules but also information on hepatocyte function. For this reasons this new approach becomes the most relevant diagnostic clue for differentiating low-risk nodules (LGDN-RN) from high-risk nodules (HGDN/early HCC or overt HCC) and consequently new diagnostic algorithms for HCC have been proposed. The use of hepatobiliary contrast agents is constantly increasing and gradually changing the standard of diagnosis of HCC. The main purpose of this review is to underline the added value of Gd-EOB-DTPA in early-stage diagnoses of HCC. We also analyse the guidelines for the diagnosis and management of HCC, the key concepts of HCC development, growth and spread and the imaging appearance of precursor nodules that eventually may transform into overt HCC.

CT/MRI LI-RADS v2017 - review of the guidelines

The Liver Imaging-Reporting and Data System (LI-RADS or LR) is a classification system for reading and reporting imaging studies in patients with high risk for hepatocellular carcinoma (HCC). One of its main goals is to improve communication between specialties, especially radiologists, hepatologists, surgeons, and pathologists. LI-RADS defines imaging features of the lesions and stratifies the risk of HCC into categories. It is the most comprehensive and highly specific system; however, its seeming complexity prevents many radiologists from using it in everyday practice. This article is a detailed review of the latest version of LI-RADS (v. 2017), which should be helpful for radiologists who are not very familiar with the system and its latest update.

Intra-individual comparison of hepatocellular carcinoma imaging features on contrast-enhanced computed tomography, gadopentetate dimeglumine-enhanced MRI, and gadoxetic acid-enhanced MRI

Background Gadoxetic acid is being widely used for detection and characterization of hepatic nodules. However, there are no data regarding intra-individual comparison of imaging features of hepatocellular carcinoma (HCC) on dynamic computed tomography (CT), gadopentetate dimeglumine-enhanced magnetic resonance imaging (Gd-DTPA-MRI), and gadoxetic acid-enhanced MRI (Gd-EOB-MRI). Purpose To evaluate typical imaging features of HCC and capsule appearance with dynamic CT, Gd-DTPA-MRI, and Gd-EOB-MRI. Material and Methods We retrospectively reviewed 56 HCCs in 49 patients. Lesion attenuation/signal intensity was graded using a five-point scale based on dynamic phase and hepatobiliary phase (HBP) imaging. Subjective washout and capsule appearance were evaluated on portal venous phase (PVP) or delayed/transitional phase (DP/TP) imaging. The tumor-to-liver contrast ratio (TLCR) was calculated. Results Gd-DTPA-MRI and Gd-EOB-MRI was graded higher than CT on arterial phase ( P < 0.001). Gd-EOB-MRI was graded lower than Gd-DTPA-MRI on PVP and DP/TP ( P < 0.05). The detection rate of subjective washout and capsule appearance did not differ among the three imaging studies on either PVP or DP/TP. TLCR of Gd-EOB-MRI was lower than CT on PVP ( P = 0.004) and was lower than Gd-DTPA-MRI on DP/TP ( P = 0.001). Conclusion Arterial phase hyperenhancement and washout appearance of HCC were well demonstrated in Gd-EOB-MRI. The detection of capsule appearance using Gd-EOB-MRI was not inferior to Gd-DTPA-MRI or CT.

Hepatocellular carcinoma with central scar on gadoxetic acid-enhanced and diffusion-weighted magnetic resonance imaging

Background Central scars are rarely reported in conventional hepatocellular carcinoma (HCC). The presence of central scars on imaging might lead to erroneous diagnosis of hepatic tumors. Purpose To determine imaging features of HCC with central scars on magnetic resonance imaging (MRI) including gadoxetic acid-enhanced and diffusion-weighted imaging (DWI). Material and Methods Fifty-one patients with 51 surgically confirmed HCCs with central scars (fibrotic scar: n = 50; myxoid scar: n = 1; range = 1.2-15 cm; mean = 3.7 cm) underwent liver MRI that consisted of T1- and T2-weighted (T2W) imaging, gadoxetic acid-enhanced arterial, portal, 3-min late phase, and 20-min hepatobiliary phase (HBP), and DWI. Two reviewers evaluated morphology, signal intensity, and enhancement features of tumors and central scars for each image and reached consensus. Results Lobulated contour was seen for 30 tumors (58.8%); the rest were round or oval masses. Central scars (range = 0.2-6.0 cm; mean = 0.9 cm) were most commonly seen as defects within hyperenhancement on arterial phase images (n = 47, 92.2%), bright (n = 28, 54.9%) or dark areas (n = 15, 29.4%) on T2W imaging, areas of central darkness on high b-value DWI (b = 800) (n = 31, 60.8%), and/or central enhancement on HBP (n = 36, 70.6%), mimicking a target appearance. Tumor capsule was seen in 35 (39 pathology, 74.5%) and intratumoral septum in 35 (41 pathology, 78.4%) tumors on gadoxetic acid-enhanced MRI. Conclusion Non-fibrolamellar HCC may show central scar. HCC with central scar mimics cholangiocarcinoma by showing a target appearance on HBP and DWI. Tumor capsule and intratumoral septum might be useful for characterizing HCC with central scar.

Health economic assessment of Gd-EOB-DTPA MRI versus ECCM-MRI and multi-detector CT for diagnosis of hepatocellular carcinoma in China

Limited data exists in China on the comparative cost of gadolinium ethoxybenzyl diethylenetriamine magnetic resonance imaging (Gd-EOB-DTPA-MRI) with other imaging techniques. This study compared the total cost of Gd-EOB-DTPA-MRI with multidetector computed tomography (MDCT) and extracellular contrast media-enhanced MRI (ECCM-MRI) as initial imaging procedures in patients with suspected hepatocellular carcinoma (HCC). We developed a decision-tree model on the basis of the Chinese clinical guidelines for HCC, which was validated by clinical experts from China. The model compared the diagnostic accuracy and costs of alternative initial imaging procedures. Compared with MDCT and ECCM-MRI, Gd-EOB-DTPA-MRI imaging was associated with higher rates of diagnostic accuracy, i.e. higher proportions of true positives (TP) and true negatives (TN) with lower false positives (FP). Total diagnosis and treatment cost per patient after the initial Gd-EOB-DTPA-MRI evaluation was similar to MDCT (¥30,360 vs. ¥30,803) and lower than that reported with ECCM-MRI (¥30,360 vs. ¥31,465). Lower treatment cost after initial Gd-EOB-DTPA-MRI was driven by reduced utilization of confirmatory diagnostic procedures and unnecessary treatments. The findings reported that Gd-EOB-DTPA-MRI offered higher diagnostic accuracy compared with MDCT and ECCM-MRI at a comparable cost, which indicates Gd-EOB-DTPA-MRI could be the preferred initial imaging procedure for the diagnosis of HCC in China.

Clinical correspondence to hepatocellular carcinoma-related lesions with atypical radiological pattern

In patients at risk of hepatocarcinogenesis, tumors are frequently detected with atypical radiological patterns related to hepatocellular carcinoma (HCC) on imaging studies. Despite their high potential for malignancy, whether to resect such lesions immediately is controversial. Based on histological findings, patients with non-enhanced tumors or enhanced tumors without washout were divided into two groups: those with tumors that should be treated containing well, moderately, and poorly differentiated HCC (Group 1), and those that can be observed containing early HCC, hepatocellular adenoma, focal nodular hyperplasia, dysplastic nodules, and regenerative nodules (Group 2), and we elucidated the clinical correspondence to these tumors. Seventy-two patients had a single tumor with atypical radiological pattern: 39 patients had HCC (Group 1), while 33 patients had benign tumors or early HCC (Group 2). Among nine baseline variables, serum α-fetoprotein (AFP) level in Group 1 (median, 13.2 ng/mL; range, 0.6-5881.6) was significantly higher than that in Group 2 (5.6 ng/mL; 0.8-86.3, P = 0.003). The cut-off value of AFP was 36.4 ng/mL for prediction of Group 1, and the median overall and recurrence-free survival periods of 23 patients in the high-AFP (≥ 36.4 ng/mL) group (5.3 years; 95%CI, 2.1 - N.A. and 1.6 years; 0.5-2.2) were significantly shorter than those of the 49 patients in the low-AFP (< 36.4) group (7.5 years; 7.5 - N.A., P = 0.047, and 2.8 years; 1.9-3.3, P = 0.001). Taken together, HCC-related tumors with an atypical radiological pattern could be observed unless serum AFP level is elevated.

Hepatocellular carcinoma: early-stage management challenges

Hepatocellular carcinoma (HCC) is a major cause of cancer death and is increasing in incidence. This review focuses on HCC surveillance and treatment of early-stage disease, which are essential to improving outcomes. Multiple societies have published HCC surveillance guidelines, but screening efforts have been limited by noncompliance and overall lack of testing for patients with undiagnosed chronic liver disease. Treatment of early-stage HCC has become increasingly complex due to expanding therapeutic options and better outcomes with established treatments. Surgical indications for HCC have broadened with improved preoperative liver testing, neoadjuvant therapy, portal vein embolization, and perioperative care. Advances in post-procedural monitoring have improved efficacies of transarterial chemoembolization and radiofrequency ablation, and novel therapies involving delivery of radiochemicals are being studied in small trials. Finally, advances in liver transplantation have allowed for expanded indications beyond Milan criteria with non-inferior outcomes. More clinical trials evaluating new therapies and multimodal regimens are necessary to help clinicians design better treatment algorithms and improve outcomes.

How to Differentiate Borderline Hepatic Nodules in Hepatocarcinogenesis: Emphasis on Imaging Diagnosis

BACKGROUND

Rapid advances in liver imaging have improved the evaluation of hepatocarcinogenesis and early diagnosis and treatment of hepatocellular carcinoma (HCC). In this situation, detection of early-stage HCC in its development is important for the improvement of patient survival and optimal treatment strategies. Because early HCCs are considered precursors of progressed HCC, precise differentiation between a dysplastic nodule (DN), especially a high-grade DN, and early HCC is important. In clinical practice, these nodules are frequently called "borderline hepatic nodules."

SUMMARY

This article discusses radiological and pathological characteristics of these borderline hepatic nodules and offers an understanding of multistep hepatocarcinogenesis by focusing on the descriptions of the imaging changes in the progression of DN and early HCC. Detection and accurate diagnosis of borderline hepatic nodules are still a challenge with contrast enhanced ultrasonography, CT, and MRI with extracellular contrast agents. However, gadoxetic acid-enhanced MRI may be useful for improving the diagnosis of these borderline nodules.

KEY MESSAGES

Since there is a net effect of incomplete neoangiogenesis and decreased portal venous flow in the early stage of hepatocarcinogenesis, borderline hepatic nodules commonly show iso- or hypovascularity. Therefore, precise differentiation of these nodules remains a challenging issue. In MRI using hepatobiliary contrast agents, signal intensity of HCCs on hepatobiliary phase (HBP) is regarded as a potential imaging biomarker. Borderline hepatic nodules are seen as nonhypervascular and hypointense nodules on the HBP, which is important for predicting tumor behavior and determining appropriate therapeutic strategies.

Small intrahepatic peripheral cholangiocarcinomas as mimics of hepatocellular carcinoma in multiphasic CT

PURPOSE

Liver transplant guidelines for diagnosing hepatocellular carcinoma (HCC) do not mandate pathologic confirmation; instead, 'classic' imaging features alone are deemed satisfactory. Intrahepatic peripheral mass forming cholangiocarcinoma (IHPMCC) is a relative contraindication for transplantation due to high rate of recurrence and poor prognosis. This study examines the imaging findings of IHPMCC, to aid in the identification and differentiation from potentially confounding cases of HCC.

METHODS

After IRB approval, 43 tissue-proven cases of IHPMCC on multiphase CT were retrospectively reviewed by 2 fellowship-trained radiologists. Tumor size, presence of cirrhosis, tumor capsule, vascular invasion, tumor markers, and enhancement pattern were assessed. A grading system was assigned as determined by enhancement pattern to background liver on arterial, portal venous, and equilibrium phases, ranging from typical HCC to typical IHPMCC enhancement pattern.

RESULTS

Analysis based on our grading system shows 5 (11.6%) tumors demonstrating grade 1-2 enhancement, 9 (21%) grade 3-4 enhancement, and 29 (67.4%) grade 5 enhancement. Kruskal-Wallis test comparing CA19-9 between the five groups, Wilcoxin rank-sum test comparing tumor markers with presence or absence of tumor capsule, vascular invasion and cirrhosis, and nonparametric Pearson's correlation coefficient comparing tumor markers to tumor size were not statistically significant (p > 0.05).

CONCLUSION

Typical enhancement pattern of IHPMCC consisting of arterial phase hypoenhancement with progressive, centripetal-delayed enhancement is present in the majority of cases (68%). Five cases (11.7%) showed enhancement features potentially mimicking HCC, all of which are under 3.5 cm in size. Thus, small hyperenhancing lesions in a cirrhotic liver should be carefully scrutinized in light of differing therapy options from HCC, particularly in transplant situations.

Gadoxetic acid-enhanced magnetic resonance imaging for the detection of small hepatocellular carcinoma (≤ 2.0 cm) in patients with chronic liver disease: A meta-analysis

AIM

To perform a meta-analysis assessing the value of gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) in detecting small hepatocellular carcinoma (HCC) (≤ 2.0 cm) in patients with chronic liver disease.

METHODS

Databases, including MEDLINE and EMBASE, were searched for relevant original articles published from January 2008 to February 2015. Data were extracted, and summary estimates of diagnostic accuracy indexes such as sensitivity, specificity, diagnostic odds ratio, predictive value, and areas under summary receiver operating characteristic curve were obtained using a random-effects model, with further exploration employing meta-regression and subgroup analyses.

RESULTS

In 10 studies evaluating 768 patients, pooled per-lesion sensitivity of Gd-EOB-DTPA was 91% (95%CI: 83%-95%), with a specificity of 95% (95%CI: 87%-98%). Overall positive likelihood ratio was 18.1 (95%CI: 6.6-49.4), for negative likelihood ratio (NLR) of 0.10 (95%CI: 0.05-0.19) and diagnostic odds ratio of 182 (95%CI: 57-581). Subgroup analysis suggested that diagnostic performance of Gd-EOB-MRI for sub-centimeter HCC (≤ 1.0 cm) detection was low, with a sensitivity of 69% (95%CI: 59%-78%). In studies with both Gd-EOB-MRI and diffusion-weighted imaging (DWI) performed, Gd-EOB-MRI/DWI combination was more sensitive than Gd-EOB-DTPA alone, whether for small lesions (86% vs 77%) or sub-centimeter ones (80% vs 56%).

CONCLUSION

A limited number of small studies suggested that Gd-EOB-MRI has good diagnostic performance in the detection of small HCC (≤ 2.0 cm) among patients with chronic liver disease, but relatively lower performance for detection of sub-centimeter HCC (≤ 1.0 cm). Combination of Gd-EOB-MRI and DWI can improve the diagnostic sensitivity of MRI.

Approach to the Solitary Liver Lesion: Imaging and When to Biopsy

The characterization and management of focal liver lesions is a commonly encountered problem in radiology. While the imaging findings will often be diagnostic, in equivocal cases the decision of how to proceed may be challenging. The primary modalities for liver lesion characterization are multiphase contrast-enhanced computed tomography and magnetic resonance imaging. Most lesions have typical imaging features, and when taken in conjunction with patient demographics and biochemistry the diagnosis can usually be made. Ancillary imaging modalities such as contrast-enhanced ultrasound and hepatobiliary specific contrast agents are also useful. Cirrhotic livers present a challenge due to the spectrum of benign, dysplastic, and malignant nodules that can occur. The report should include information necessary for accurate staging, and published standardized reporting guidelines should be taken into consideration. A decision to proceed to biopsy should be made only after multidisciplinary review of the case. If biopsy is required, fine needle aspiration is usually sufficient, though core needle biopsy may be required in certain circumstances.

The role of the diffusion sequence in magnetic resonance imaging for the differential diagnosis between hepatocellular carcinoma and benign liver lesions

Background and aim

To assess the role of diffusion weighted imaging sequence (DWI), routinely used in hepatic magnetic resonance imaging (MRI) for the differentiation of hepatocellular carcinoma (HCC) from benign liver lesions.

Methods

A number of 56 liver MRI examinations were retrospectively analyzed independently by two experienced radiologists, blinded to each other results. A total number of 70 Focal Liver Lesions (FLLs) assessed by liver MRI in 56 patients were included in the present study. All lesions were retrospectively analyzed by two experienced radiologists, independently from each other and who were not aware of the previous results given by using different imaging techniques. All included FLLs had a final histological diagnosis, or the final diagnosis was based on consensus reading by two experienced radiologists. The signal of the included FLLs was qualitatively appreciated on the b-800 sequences and on the apparent diffusion coefficient (ADC) map. The ADC value of each FLL was measured and the ADC ratio between the ADC value of the assessed FLL and that of the surrounding liver parenchyma was calculated.

Results

The mean ADC value for benign FLLs as assessed by the two independent readers was 1.75 × 10⁻³ and 1.72 × 10⁻³. The mean ADC value for HCC nodules was 0.92 × 10⁻³ for the first reader and 0.91 × 10⁻³ for the second reader respectively. The mean ADC ratio for benign FLLs was 1.81 and 1.84 for the two readers, respectively. The ADC ratio for HCC nodules was 0.91 and 0.91, respectively. The ADC value is an indicator which is less prone to interobserver variability (correlation of 0.919→1). The ADC ratio has, as the analysis of the ROC curve shows, the best predictive value for differentiation between benign FLLs and HCC nodules. Analysis of the signal intensity on the DWI b-800 image alone is of no significance in differentiating benign FLLs from HCC nodules (p>0.005).

Conclusions

The ADC value and the ADC ratio assessed on liver DWI are useful diagnostic tools in the differential diagnosis of benign FLLs vs HCC nodules. Quantitative methods such as calculating the ADC value or ADC ratio have better diagnostic value than qualitative techniques.

Recent Advances in the Imaging Diagnosis of Hepatocellular Carcinoma: Value of Gadoxetic Acid-Enhanced MRI

Magnetic resonance imaging (MRI) using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DPTA), or gadoxetic acid for short, is a hepatocyte-specific contrast agent which is now increasingly used for the detection and characterization of focal hepatic lesions, particularly in patients at high-risk of developing hepatocellular carcinomas (HCC). In fact, several recent guidelines now recognize gadoxetic acid-enhanced MRI (Gd-EOB-MRI) as the primary diagnostic imaging modality for the noninvasive diagnosis of HCC, although it must be noted that several major guidelines still include only extracellular contrast media-enhanced computed tomography and MRI. The primary merits of Gd-EOB-MRI lie in the fact that it can provide not only dynamic imaging, but also hepatobiliary phase (HBP) imaging which can lead to high lesion-to-liver contrast and give additional information regarding hepatocyte uptake via organic anion transporting polypeptides. This, in turn, allows higher sensitivity in detecting small HCCs and helps provide additional information regarding the multistep process of hepatocarcinogenesis. Indeed, many recent studies have investigated the diagnostic value of Gd-EOB-MRI for early HCCs as well as its role as a potential imaging biomarker in predicting outcome. We herein review the recent advances in the imaging diagnosis of HCCs focusing on the applications of Gd-EOB-MRI and the challenging issues that remain.

Recent advances in the imaging of hepatocellular carcinoma

The role of imaging is crucial for the surveillance, diagnosis, staging and treatment monitoring of hepatocellular carcinoma (HCC). Over the past few years, considerable technical advances were made in imaging of HCCs. New imaging technology, however, has introduced new challenges in our clinical practice. In this article, the current status of clinical imaging techniques for HCC is addressed. The diagnostic performance of imaging techniques in the context of recent clinical guidelines is also presented.

Liver metastasis from hepatoid adenocarcinoma of the stomach mimicking hepatocellular carcinoma: Dynamic computed tomography findings

AIM: To evaluate the dynamic computed tomography (CT) findings of liver metastasis from hepatoid adenocarcinoma of the stomach (HAS) and compared them with hepatocellular carcinoma (HCC).

METHODS: Between January 2000 and January 2015, 8 patients with pathologically proven HAS and liver metastases were enrolled. Basic tumor status was evaluated for the primary tumor location and metastatic sites. The CT findings of the liver metastases were analyzed for tumor number and size, presence of tumor necrosis, hemorrhage, venous tumor thrombosis, and dynamic enhancing pattern.

RESULTS: The body and antrum were the most common site for primary HAS (n = 7), and observed metastatic sites included the liver (n = 8), lymph nodes (n = 7), peritoneum (n = 4), and lung (n = 2). Most of the liver metastases exhibited tumor necrosis regardless of tumor size. By contrast, tumor hemorrhage was observed only in liver lesions larger than 5 cm (n = 4). Three patterns of venous tumor thrombosis were identified: direct venous invasion by the primary HAS (n = 1), direct venous invasion by the liver metastases (n = 7), and isolated portal vein tumor thrombosis (n = 2). Dynamic CT revealed arterial hyperattenuation and late phase washout in all the liver metastases.

CONCLUSION: On dynamic CT, liver metastasis from HAS shared many imaging similarities with HCC. For liver nodules, the presence of isolated portal vein tumor thrombosis and a tendency for tumor necrosis are imaging clues that suggest the diagnosis of HAS.

CT of Atypical and Uncommon Presentations of Hepatocellular Carcinoma

OBJECTIVE

The purpose of this article is to familiarize radiologists with uncommon presentations of hepatocellular carcinoma (HCC) with an emphasis on the CT spectrum of atypical appearances.

CONCLUSION

HCC is the fifth most common neoplasm worldwide and the second most common cause of cancer-related death. In many cases, HCC can be confidently diagnosed with noninvasive imaging. However, there are numerous unusual appearances of HCC with which the radiologist must be familiar.

Combined Application of Gadoxetic Acid Disodium-Enhanced Magnetic Resonance Imaging (MRI) and Diffusion-Weighted Imaging (DWI) in the Diagnosis of Chronic Liver Disease-Induced Hepatocellular Carcinoma: A Meta-Analysis

Objective

Gadoxetic acid disodium (Gd-EOB-DTPA) is a magnetic resonance imaging (MRI) contrast agent to target the liver cells with normal function. In clinical practice, the Gd-EOB-DTPA produces high quality hepatocyte specific image 20 minutes after intravenous injection, so DWI sequence is often performed after the conventional dynamic scanning. However, there are still some disputes about whether DWI sequence will provide more effective diagnostic information in clinical practice. This study aimed to explore the diagnostic value of combining Gd-EOB-DTPA-enhanced MRI and DWI in the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease.

Methods

A systematic literature search was performed in the PubMed and Cochrane library database up to March 2015. The quality assessment of diagnostic accuracy studies (QUADAS) was used to evaluate the quality of studies. Heterogeneous test on the included literature was performed by using the software Review Manager 5.3. The MetaDiSc 1.4 software was used to calculate the pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio; meanwhile the summary receiver operating characteristics (SROC) curve was drawn to compare the diagnostic performance.

Results

A total of 13 literatures were included in this study. In 8 literatures regarding HCC diagnosis based on Gd-EOB-DTPA-enhanced MRI, the pooled sensitivity: 0.90 (95% confidence interval (CI): 0.88–0.93); specificity: 0.89 (95% CI: 0.85–0.92); positive likelihood ratio: 8.60 (95% CI: 6.20–11.92); negative likelihood ratio: 0.10 (95% CI: 0.08–0.14) were obtained. The area under curve (AUC) and Q values were 0.96 and 0.90, respectively. In 5 literatures relating to HCC diagnosis by combination of Gd-EOB-DTPA-enhanced MRI and DWI sequence, the pooled sensitivity: 0.88 (95% CI: 0.85–0.91), specificity: 0.96 (0.94–0.97), positive likelihood ratio: 19.63 (12.77–30.16), negative likelihood ratio: 0.10 (0.07–0.14) were obtained. The AUC value was 0.9833 and Q value was 0.9436. The AUC value of comprehensive evaluation method was significantly higher than that of Gd-EOB-DTPA-enhanced MRI alone(P<0.05).

Conclusion

Combination of Gd-EOB-DTPA-enhanced MRI and DWI sequence significantly improves in both the diagnostic accuracy and specificity of chronic liver disease-associated HCC.

Diagnosing Borderline Hepatic Nodules in Hepatocarcinogenesis: Imaging Performance

OBJECTIVE

The purposes of this article are to describe the pathologic and radiologic features of small nodular lesions and to offer insight into the multistep process of hepatocarcinogenesis by describing the progression of imaging changes that link dysplastic nodules and early hepatocellular carcinoma, (HCC) to small HCC that has progressed.

CONCLUSION

Nodules larger than 1 cm found during ultrasound surveillance of a cirrhotic liver should be investigated further with diagnostic imaging. Contrast-enhanced CT and dynamic MRI are the primary diagnostic studies for the diagnosis of HCC; contrast-enhanced ultrasound can be used as an alternative test. If a nodule has the typical hallmark of hypervascularity in the hepatic arterial phase with washout in the portal venous or delayed phase, a definitive diagnosis of HCC can be made. Nodules found during ultrasound surveillance that are smaller than 1 cm can be followed with ultrasound examinations at intervals of 3-6 months.

Utility of non-contrast-enhanced CT for improved detection of arterial phase hyperenhancement in hepatocellular carcinoma

PURPOSE

To determine the utility of non-contrast-enhanced CT (NC-CT) for improved detection of hyperenhancement in hepatocellular carcinomas (HCC).

METHODS

We performed a retrospective analysis on CT studies of 104 consecutive patients with 124 HCCs between October 2006 and December 2012. The enhancement of HCC was evaluated on quadriphasic CT: non-contrast (NC), arterial phase (AP), portal-venous phase (PVP), and delayed phases (DP) were performed. For determination of enhancement, mean attenuation of the HCC and surrounding non-tumor bearing liver in the four phases were recorded. Hyperenhancement was defined by either HCC (AP-NC) representing absolute lesion enhancement or AP (HCC-liver), representing relative enhancement. An increase of ≥10 Hounsfield units (HU) was considered as enhancement. Two radiologists (R1 and R2) independently performed a conventional qualitative assessment for hyperenhancement of HCC. The accuracy of detection by proposed absolute lesion enhancement HCC (AP-NC) was compared to relative enhancement AP (HCC-liver) and qualitative assessment by readers with the McNemar test.

RESULTS

The proposed criteria of absolute lesion enhancement, HCC (AP-NC) identified more hypervascular nodules compared to qualitative analysis (92% vs. 62% for R1 and 69% for R2), equating to an improvement of 23%-31%. In contrast, relative enhancement AP (HCC-liver) was found to be inferior to conventional qualitative analysis (50% vs. 62%-69% for readers).

CONCLUSION

NC-CT is useful to improve the detection of hyperenhancement in HCCs for imaging diagnosis.

Focal lesions in cirrhotic liver: what else beyond hepatocellular carcinoma?

Detection and characterization of focal lesions in the cirrhotic liver may pose a diagnostic dilemma. Several benign and malignant lesions may be found in a cirrhotic liver along with hepatocellular carcinoma (HCC), and may exhibit typical or atypical imaging features. In this pictorial essay, we illustrate computed tomography and magnetic resonance imaging findings of lesions such as simple bile duct cysts, hemangioma, focal nodular hyperplasia-like nodules, peribiliary cysts, intrahepatic cholangiocarcinoma, lymphoma, and metastases, all of which occur in cirrhotic livers with varying prevalences. Pseudolesions, such as perfusion anomalies, focal confluent fibrosis, and segmental hyperplasia, will also be discussed. Imaging characterization of non-HCC lesions in cirrhosis is important in formulating an accurate diagnosis and triaging the patient towards the most appropriate management.

Hepatocellular carcinoma: Consensus, controversies and future directions. A report from the Canadian Association for the Study of the Liver Hepatocellular Carcinoma Meeting

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide and its incidence has rapidly increased in North America in recent years. Although there are many published guidelines to assist the clinician, there remain gaps in knowledge and areas of controversy surrounding the diagnosis and management of HCC. In February 2014, the Canadian Association for the Study of the Liver organized a one-day single-topic consensus conference on HCC. Herein, the authors present a summary of the topics covered and the result of voting on consensus statements presented at this meeting.