The diagnostic and economic impact of contrast imaging techniques in the diagnosis of small hepatocellular carcinoma in cirrhosis

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

Gadoxetic acid-enhanced MRI for diagnosis of hepatocellular carcinoma in patients with chronic liver disease: can hypointensity on the late portal venous phase be used as an alternative to washout?

PURPOSE

To investigate the added value of considering hypointensity on late portal venous phase (LPVP) images as washout for diagnosis of hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced MRI (Gd-EOB-MRI) in patients with chronic liver disease (CLD).

METHODS

This retrospective study comprised 97 patients at high risk for HCC who underwent Gd-EOB-MRI including unenhanced, multi-arterial phase, conventional portal venous phase (CPVP, 60 s), and LPVP (mean, 99.9 ± 9.1 s; range, 90-119 s) images. A total of 115 hepatic lesions were identified by histopathological or clinical diagnosis. Three independent radiologists assessed the MRI images by consensus. Diagnosis of HCC was made using criteria of arterial hyperenhancement and hypointensity relative to the surrounding liver parenchyma (1) on CPVP or (2) on CPVP and/or LPVP images. The generalized estimating equation was used to compare diagnostic performance for HCC between Criterion 1 and 2.

RESULTS

In 82 HCCs, the frequency of hypointensity differed significantly between the CPVP and LPVP images (64.6% [53/82] vs. 84.1% [69/82], P < 0.001). Among 33 non-HCCs, two cHCC-CCs showed additional hypointensity on LPVP than CPVP images (33.3% [11/33] vs. 39.4% [13/33], P = 0.500). Criterion 2 provided significantly greater sensitivity for diagnosing HCC than Criterion 1 (54.9% [45/82] vs. 74.4% [61/82], P < 0.001), with relatively little reduction in specificity (90.9% [30/33] vs. 84.8% [28/33], P = 0.145).

CONCLUSION

Additional use of LPVP hypointensity as washout could significantly improve sensitivity for HCC diagnosis when utilizing Gd-EOB-MRI in patients with CLD, without a significant decrease in specificity.

Classification of hepatocellular carcinoma and intrahepatic cholangiocarcinoma based on multi-phase CT scans

Liver and bile duct cancers are leading causes of worldwide cancer death. The most common ones are hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). Influencing factors and prognosis of HCC and ICC are different. Precise classification of these two liver cancers is essential for treatment and prevention plans. The aim of this study is to develop a machine-based method that differentiates between the two types of liver cancers from multi-phase abdominal computerized tomography (CT) scans. The proposed method consists of two major steps. In the first step, the liver is segmented from the original images using a convolutional neural network model, together with task-specific pre-processing and post-processing techniques. In the second step, by looking at the intensity histograms of the segmented images, we extract features from regions that are discriminating between HCC and ICC, and use them as an input for classification using support vector machine model. By testing on a dataset of labeled multi-phase CT scans provided by Maharaj Nakorn Chiang Mai Hospital, Thailand, we have obtained 88% in classification accuracy. Our proposed method has a great potential in helping radiologists diagnosing liver cancer.

Magnetic Resonance Imaging With Extracellular Contrast Detects Hepatocellular Carcinoma With Greater Accuracy Than With Gadoxetic Acid or Computed Tomography

BACKGROUND & AIMS

Computed tomography (CT) and magnetic resonance imaging (MRI) are used to detect hepatocellular carcinoma (HCC). We performed a prospective study to compare the diagnostic performance of CT, MRI with extracellular contrast agents (ECA-MRI), and MRI with hepatobiliary agents (HBA-MRI) in the detection of HCC using the liver imaging reporting and data system (LI-RADS).

METHODS

We studied 125 participants (102 men; mean age, 55.3 years) with chronic liver disease who underwent CT, ECA-MRI, or HBA-MRI (with gadoxetic acid) before surgery for a nodule initially detected by ultrasound at a tertiary center in Korea, from November 2016 through February 2019. We collected data on major features and assigned LI-RADS categories (v2018) from CT and MRI examinations. We then compared the diagnostic performance for LR-5 for each modality alone, and in combination.

RESULTS

In total, 163 observations (124 HCCs, 13 non-HCC malignancies, and 26 benign lesions; mean size, 20.7 mm) were identified. ECA-MRI detected HCC with 83.1% sensitivity and 86.6% accuracy, compared to 64.4% sensitivity and 71.8% accuracy for CT (P < .001) and 71.2% sensitivity (P = .005) and 76.5% accuracy for HBA-MRI (P = .005); all technologies detected HCC with 97.4% specificity. Adding CT to either ECA-MRI (89.2% sensitivity, 91.4% accuracy; both P < .05) or HBA-MRI (82.8% sensitivity, 86.5% accuracy; both P < .05) significantly increased its diagnostic performance in detection of HCC compared with the MRI technologies alone. ECA-MRI identified arterial phase hyperenhancement in a significantly higher proportion of patients (97.6%) than CT (81.5%; P < .001) or HBA-MRI (89.5%; P = .002). ECA-MRI identified non-peripheral washout in 79.8% of patients, vs 74.2% of patients for CT and 73.4% of patients for HBA-MRI (differences not significant). ECA-MRI identified enhancing capsules in 85.5% of patients, vs 33.9% for CT (P < .001) and 41.4% for HBA-MRI (P < .001).

CONCLUSION

In a prospective study of patients with chronic liver disease and a nodule detected by ultrasound, ECA-MRI detected HCC with higher levels of sensitivity and accuracy than CT or HBA-MRI, based on LI-RADS. Diagnostic performance was best when CT was used in combination with MRI compared with MRI alone.

Initial experience with stereotactic body radiotherapy for intrahepatic hepatocellular carcinoma recurrence after liver transplantation

BACKGROUND

Graft hepatocellular carcinoma (HCC) recurrence after liver transplant is more frequently encountered. Graft hepatectomy is technically challenging and is associated with high morbidity. Stereotactic body radiation therapy (SBRT) has been shown to be safe and effective for the treatment of primary HCC. However, its role in HCC recurrence in a liver graft remains unclear.

AIM

To evaluate the safety and efficacy of SBRT for the treatment of graft HCC recurrence after liver transplantation.

METHODS

A retrospective study was conducted. From 2012 to 2018, 6 patients with intrahepatic HCC recurrence after liver transplant were treated with SBRT at Queen Mary Hospital, the University of Hong Kong. The primary outcome was time to overall disease progression and secondary outcomes were time to local progression and best local response, as assessed with the Modified response Evaluation Criteria for Solid Tumours criteria. Patients were monitored for treatment related toxicities and graft dysfunction.

RESULTS

A total of 9 treatment courses were given for 13 tumours. The median tumour size was 2.3 cm (range 0.7-3.6 cm). Two (22%) patients had inferior vena cava tumour thrombus. The best local treatment response was: 5 (55%) complete response, 1 (11%) partial response and 3 (33%) stable disease. After a median follow up duration of 15.5 mo, no local progression or mortality was yet observed. The median time to overall disease progression was 6.5 mo. There were 6 regional progression in the liver graft (67%) and 2 distant progression in the lung (22%). There was no grade 3 or above toxicity and there was no graft dysfunction after SBRT.

CONCLUSION

SBRT appears to be safe in this context. Regional progression is the mode of failure.

Emerging Role of Hepatobiliary Magnetic Resonance Contrast Media and Contrast-Enhanced Ultrasound for Noninvasive Diagnosis of Hepatocellular Carcinoma: Emphasis on Recent Updates in Major Guidelines

Hepatocellular carcinoma (HCC) can be noninvasively diagnosed on the basis of its characteristic imaging findings of arterial phase enhancement and portal/delayed “washout” on computed tomography (CT) and magnetic resonance imaging (MRI) in cirrhotic patients. However, different specific diagnostic criteria have been proposed by several countries and major academic societies. In 2018, major guideline updates were proposed by the Association for the Study of Liver Diseases, European Association for the Study of the Liver (EASL), Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) of Korea. In addition to dynamic CT and MRI using extracellular contrast media, these new guidelines now include magnetic resonance imaging (MRI) using hepatobiliary contrast media as the first-line diagnostic test, while the KLCA-NCC and EASL guidelines also include contrast-enhanced ultrasound (CEUS) as the second-line diagnostic test. Therefore, hepatobiliary MR contrast media and CEUS will be increasingly used for the noninvasive diagnosis and staging of HCC. In this review, we discuss the emerging role of hepatobiliary phase MRI and CEUS for the diagnosis of HCC and also review the changes in the HCC diagnostic criteria in major guidelines, including the KLCA-NCC practice guidelines version 2018. In addition, we aimed to pay particular attention to some remaining issues in the noninvasive diagnosis of HCC.

Using the Controlling Nutritional Status (CONUT) Score for Evaluating Patients with Early-Stage Hepatocellular Carcinoma After Radiofrequency Ablation: A Two-Center Retrospective Study

PURPOSE

To estimate the prognostic significance of the controlling nutritional status (CONUT) in patients with BCLC stage A hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA).

MATERIALS AND METHODS

From January 2013 to December 2016, 325 patients with BCLC stage A HCC who underwent RFA at the National Cancer Center and First Hospital of Shanxi Medical University were retrospectively studied. The patients were divided into low (≤ 4) and high (≥ 5) CONUT scores for assessment of overall survival (OS) and recurrence-free survival (RFS). Several covariates, including age, sex, the diameter and number of lesions, lesion differentiation, Child-Pugh class, hepatitis B virus infection, along with blood levels of AFP, AST, ALT, γ-GT, and TBIL, were assessed using univariate and multivariate analyses.

RESULTS

The mortality rate was 17.49% (46/263) and 35.48% (22/62) in the low and high CONUT groups, respectively, with the difference being statistically significant (P = 0.033). In addition, disease recurrence was significantly higher in the high CONUT group at 70.97%, as compared to the low CONUT group at 43.35% (P = 0.041). The predictive factors were used to build the nomogram to estimate 1-, 3- and 5-year OS and RFS rates.

CONCLUSIONS

CONUT scores were found to be associated with the prognosis of patients with early-stage HCC who underwent RFA. Higher CONUT scores were associated with poor survival outcomes.

Contrast imaging techniques to diagnose hepatocellular carcinoma in cirrhotics outside regular surveillance

INTRODUCTION AND AIM

The American Association for the Study of the Liver (AASLD) recommends contrast computerized tomography (CT-scan) and magnetic resonance (MRI) to diagnose hepatocellular carcinoma (HCC) arising in cirrhotic patients under semiannual surveillance with abdominal ultrasound (US). A US guided fine needle biopsy (FNB) serves the same purpose in radiologically undiagnosed tumors and incidentally detected nodules in cirrhotics outside surveillance. In this population, we evaluated the performance of radiological diagnosis of HCC according to 2010 AASLD recommendations.

MATERIALS AND METHODS

All cirrhotic patients with a liver nodule incidentally detected by US were prospectively investigated with a sequential application of CT-scan/MRI examination and a FNB.

RESULTS

Between 2011 and 2015, 94 patients (mean age 67 years) had a liver nodule (total 120) detected by US in the context of histologically confirmed cirrhosis. Mean nodules diameter was 40 (10-160) mm, 87 (73%) <5cm. At histology, 84 (70%) nodules were HCC, 8 (7%) intrahepatic cholangiocarcinoma, 6 (5%) metastases, 2 (2%) neuroendocrine tumors and 20 (16%) benign lesions. Hyperenhancement in arterial phase followed by wash-out in venous phases on at least one radiological technique was demonstrated in 62 nodules (61 HCC, 1 high grade dysplastic nodule), with a specificity of 97% (IC95%: 85-100%), sensitivity 73% (IC95%: 62-81%) and diagnostic accuracy 80%, being 64% for ≥5cm HCC. Sensitivity of AFP >200ng/mL was 12% (IC95%: 6-23%).

CONCLUSION

A single contrast imaging technique showing a typical contrast pattern confidently identifies HCC also in cirrhotic patients with an incidental liver nodule, thereby reducing the need for FNB examinations.

Utility of positron emission tomography-computed tomography scan in detecting residual hepatocellular carcinoma post treatment: Series of case reports

BACKGROUND

Multi-phase computed tomography (CT) or magnetic resonance imaging (MRI) has been the standard of care for hepatocellular carcinoma (HCC) diagnosis for years.

CASE SUMMARY

We report a case series of four patients in whom positron emission tomography-computed tomography (PET-CT) scan complemented the conventional CT/MRI scans in evaluating treatment response. In these four cases the conventional multi-phase CT and MRI failed to identify residual HCC disease post-treatment, while PET-CT complemented and aided in treatment response evaluation. In each case, the addition of PET-CT identified and located residual HCC disease, allowed retreatment, and altered medical management.

CONCLUSION

This case series suggests that PET-CT should perhaps play a role in the HCC management algorithm, in addition to the conventional contrast-enhanced multi-phase scans.

A combination of α-fetoprotein, midkine, thioredoxin and a metabolite for predicting hepatocellular carcinoma

INTRODUCTION AND OBJECTIVES

The heterogenous nature of hepatocellular carcinoma (HCC) motivated this attempt at developing and validating a model based on combined biomarkers for improving early HCC detection.

PATIENTS/MATERIALS AND METHODS

This study examined 196 patients for an estimation study (104 patients with HCC, 52 with liver cirrhosis and 40 with liver fibrosis) and 122 patients for the validation study (80 patients with HCC, 42 with liver cirrhosis). All patients were positive for hepatitis C virus. Four markers were measured: Midkine and thioredoxin using ELISA, 1-methyladenosine and 1-methylguanosine using a gas chromatography-mass spectrometry (GC-MS). The results were compared with alpha-fetoprotein (AFP). The performance of the model was estimated in BCLC, CLIP and Okuda staging systems of HCC.

RESULTS

The model yielded high performance with an area under ROC (AUC) of 0.94 for predicting HCC in patients with liver cirrhosis, compared with AUC of 0.69 for AFP. This model had AUCs of 0.93, 0.94 and 0.94 in patients who had only one single nodule, absent macrovascular invasion and tumor size <2cm, respectively, compared with AUCs of 0.71, 0.6 and 0.59 for AFP. The model produced AUCs of 0.91 for BCLC (0-A), 0.92 for CLIP (0-1) and 0.94 for Okuda (stage I) compared with AUCs of 0.56, 0.58 and 0.64 for AFP. No significant difference was found between AUC in the estimation and the validation groups.

CONCLUSION

This model may enhance early-stage HCC detection and help to overcome insufficient sensitivity of AFP.

Epidemiology and surveillance for hepatocellular carcinoma: New trends

The burden of hepatocellular carcinoma (HCC) is highest in East Asia and Africa, although its incidence and mortality are rapidly rising in the United States and Europe. With the implementation of hepatitis B vaccination and hepatitis C treatment programmes worldwide, the epidemiology of HCC is shifting away from a disease predominated by viral hepatitis - an increasing proportion of cases are now attributable to non-alcoholic steatohepatitis. Surveillance using ultrasound, with or without alpha-fetoprotein, every 6 months has been associated with improved early detection and improved overall survival; however, limitations in implementation lead to a high proportion of HCC being detected at late stages in clinical practice. Herein, we review the current state of HCC surveillance and highlight areas for future research, including improved risk stratification of at-risk patients, surveillance tools with higher sensitivity and specificity for early HCC, and interventions to increase surveillance utilisation.

Hepatocellular carcinoma surveillance with liver imaging is not associated with improved survival

Objective: International guidelines recommend hepatocellular carcinoma (HCC) surveillance with ultrasound in high-risk patients with chronic liver diseases. However, there is low-strength evidence about the effects on mortality. The aim of our study was to assess the impact of surveillance on the clinical course and survival of HCC patients seen at a tertiary referral center in Germany.Material and methods: We retrospectively evaluated the data of 401 HCC patients, who presented to our clinic between 1997 and 2015. Two groups were compared regarding patient and disease outcomes: one group included patients who received at least two ultrasound examinations for surveillance purposes prior to first diagnosis (n = 111). The other group consisted of patients with HCC at first presentation without foregoing HCC surveillance (n = 290).Results: Median follow-up in the surveillance group was 76 months (range 4-310 months). Patients in the surveillance group had smaller median tumor sizes (3.5 cm vs. 4.5 cm; p < .001), fulfilled more often Milan criteria (64% vs. 42%; p < .001) and received more often liver transplantation (27% vs. 9%, p < .001) when compared with the non-surveillance group. However, HCC surveillance was not associated with an improved survival (14 months in the surveillance group vs. 12 months in the non-surveillance group, p = .375), hazard ratio regarding overall mortality for the surveillance group: 0.80 (95% CI: 0.62-1.04, p = .09).Conclusions: HCC surveillance with ultrasound led to the detection of earlier disease stages but was not significantly associated with improved survival. Further prospective and long-term studies are needed to clarify benefits and harms of HCC surveillance programs on mortality.

A proposal for a useful algorithm to diagnose small hepatocellular carcinoma on MRI

OBJECTIVE

To assess MRI features for the diagnosis of small hepatocellular carcinomas (HCCs) and especially for nodules not showing both of the typical hallmarks.

PATIENTS AND METHODS

Three hundred and sixty-four cirrhotic patients underwent liver MRI for 10-30 mm nodules suggestive of HCC. The diagnostic performances of MRI features [T1, T2; diffusion-weighted (DW) imaging signal, enhancement, capsule, fat content] were tested, both individually and in association with both typical hallmarks and as substitutions for one hallmark. The diagnostic reference was obtained using a multifactorial algorithm ensuring high specificity (Sp).

RESULTS

Four hundred and ninety-three nodules were analyzed. No alternative features, associations or substitutions outperformed the typical hallmarks for the diagnosis of HCC. For 10-20 mm nodules not displaying one of the typical hallmarks, hyperintensity on DW images was the most accurate substitutive sign, providing a sensitivity of 71.4% and Sp of 75% for nodules without arterial enhancement and sensitivity = 65.2% and Sp = 66% for nodules without washout on the portal or delayed phases. A new diagnostic algorithm, including typical hallmarks as a first step then the best-performing substitutive signs (capsule presence or DW hyperintensity) in combination with the nonmissing typical hallmark as a second step, enabled the correct classification of 77.7% of all nodules, regardless of size.

CONCLUSION

Using MRI, the typical hallmarks remain the best criteria for the diagnosis of small HCCs. However, by incorporating other MRI features, it is possible to build a simple algorithm enabling the noninvasive diagnosis of HCCs displaying both or only one of the typical hallmarks.

Sensitivity of ultrasound in detecting hepatocellular carcinoma in obese patients compared to explant pathology as the gold standard

Background/Aims

The American Association for the Study of Liver Diseases recommends ultrasound (US) screening for hepatocellular carcinoma (HCC) among cirrhotic patients, regardless of body mass index (BMI), every 6 months. We examined US sensitivity for diagnosis of HCC in obese patients.

Methods

Liver transplant patients data with HCC in explant was used (January 2012-December 2017). All patients underwent liver US within 3 months of diagnosis of HCC. Number/size of HCC lesions were extracted from radiologic and pathologic reports. Obesity was defined as BMI ≥30 kg/m².

Results

One hundred sixteen patients were included. 80% were male, with mean BMI of 31 kg/m². The most common underlying liver disease was hepatitis C virus (62%). At the time of diagnosis, median number of HCC lesions was 2 (interquartile range [IQR], 1–3), and median size of the largest lesion was 2.5 cm (IQR, 1.75–3.9). Overall sensitivity of US study for detection of HCC was 33% (95% confidence interval [CI], 29–48%). Sensitivity was 77% (95% CI, 62–93%) in patients with BMI<30 and 21% (95% CI, 11–30%) in patients with BMI≥30 (P<0.001). Size of the largest HCC lesion (P=0.290) and number of lesions (P=0.505) were not different between groups. Computed tomography (CT) scan detected HCC in 98% of the obese patients with negative US.

Conclusions

Sensitivity of US for detection of HCC is significantly lower among obese patients compared to overweight and normal weight patients. These patients may benefit from alternating between US and a different imaging modality.

Profiling of plasma metabolomics in patients with hepatitis C-related liver cirrhosis and hepatocellular carcinoma

Aim of the study

The diagnosis of hepatocellular carcinoma (HCC) is usually late, due to the lack of early detection of biomarkers for HCC. Metabolomics analysis has emerged as a useful tool for studying human diseases. The objective of the study was to investigate the differences in plasma metabolites between hepatitis C virus (HCV)-induced cirrhosis and HCC.

Material and methods

22 subjects with HCV-related liver cirrhosis and 22 subjects with HCC were enrolled. Clinical, routine laboratory and imaging studies were done. Gas chromatography/mass spectrometry (GC/MS) was used for metabolomics analysis of patients' plasma samples.

Results

34 known metabolites were detected, of which five metabolites were identified to have the strongest discriminatory power for separation between HCC and cirrhosis groups: octanoic acid (caprylic acid), decanoic (capric acid), oleic acid, oxalic acid and glycine. These are 3 fatty acids (FA), a dicarboxylic acid and a glucogenic amino acid, respectively. No significant correlation was found between the relative intensities of the five metabolites and any of the patient or tumor characteristics (Child-Turcotte-Pugh (CTP) score, Barcelona Clinic Liver Cancer (BCLC) stage, number of focal lesions and size of largest focal lesion). ROC curve analysis was performed and area under the curve (AUC) was calculated, revealing that oleic acid, octanoic (caprylic) acid and glycine had higher positive predictive value than α-fetoprotein.

Conclusions

The study of metabolomics (particularly involving FA) may help define distinct metabolic patterns to distinguish HCV-induced liver cirrhosis from HCC patients. Future research in this field is still needed, particularly concerning HCC treatment strategies which target fatty acid-related metabolic pathways.

Real-Time Contrast-Enhanced-Guided Biopsy Compared with Conventional Ultrasound-Guided Biopsy in the Diagnosis of Hepatic Tumors on a Background of Advanced Chronic Liver Disease: A Prospective, Randomized, Clinical Trial

We aimed to compare contrast-enhanced-guided liver biopsy (CEUSLB) and ultrasound-guided liver biopsy (USLB) in the diagnosis of focal liver lesions (FLLs) developed on a background of advanced chronic liver disease (ACLD). Between 2011 and 2019, patients diagnosed with liver tumors on a background of ACLD were evaluated for inclusion in the study. Patients were randomly assigned to the CEUSLB or USLB group. In total, 144 patients were randomly assigned to either CEUSLB (n = 79) or USLB (n = 65). Overall, in the CEUSLB group, the sensitivity was significantly better (94.74% vs. 74.6%, respectively; p = 0.001). Both the fragment length of the biopsy specimen and the single puncture success rate were statistically higher in the CEUSLB group (p = 0.022 and p = 0.0006, respectively). There was no difference in terms of major or minor complications (p = 0.682). CEUSLB is a feasible technique that increases the diagnostic sensitivity for liver tumors developed in ACLD.

Role of liver biopsy in hepatocellular carcinoma

The role of liver biopsy in the diagnosis of hepatocellular carcinoma (HCC) has been challenged over time by the ability of imaging techniques to characterize liver lesions in patients with known cirrhosis. In fact, in the diagnostic algorithm for this tumor, histology is currently relegated to controversial cases. Furthermore, the risk of complications, such as tumor seeding and bleeding, as well as inadequate sampling have further limited the use of liver biopsy for HCC management. However, there is growing evidence of prognostic and therapeutic information available from microscopic and molecular analysis of HCC and, as the information content of the tissue sample increases, the advantages of liver biopsy might modify the current risk/benefit ratio. We herein review the role and potentiality of liver biopsy in the diagnosis and management of HCC. As the potentiality of precision medicine comes to the management of HCC, it will be crucial to have rapid pathways to define prognosis, and even treatment, by identifying the patients who could most benefit from target-driven therapies. All of the above reasons suggest that the current role of liver biopsy in the management of HCC needs substantial reconsideration.

Surveillance and diagnosis of hepatocellular carcinoma: A systematic review

BACKGROUND

Hepatocellular carcinoma (HCC) appears in most of cases in patients with advanced liver disease and is currently the primary cause of death in this population. Surveillance of HCC has been proposed and recommended in clinical guidelines to obtain earlier diagnosis, but it is still controversial and is not accepted worldwide.

AIM

To review the actual evidence to support the surveillance programs in patients with cirrhosis as well as the diagnosis procedure.

METHODS

Systematic review of recent literature of surveillance (tools, interval, cost-benefit, target population) and the role of imaging diagnosis (radiological non-invasive diagnosis, optimal modality and agents) of HCC.

RESULTS

The benefits of surveillance of HCC, mainly with ultrasonography, have been assessed in several prospective and retrospective analysis, although the percentage of patients diagnosed in surveillance programs is still low. Surveillance of HCC permits diagnosis in early stages allows better access to curative treatment and increases life expectancy in patients with cirrhosis. HCC is a tumor with special radiological characteristics in computed tomography and magnetic resonance imaging, which allows highly accurate diagnosis without routine biopsy confirmation. The actual recommendation is to perform biopsy only in indeterminate nodules.

CONCLUSION

The evidence supports the recommendation of performing surveillance of HCC in patients with cirrhosis susceptible of treatment, using ultrasonography every 6 mo. The diagnosis evaluation of HCC can be established based on noninvasive imaging criteria in patients with cirrhosis.

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.

Prospective evaluation of gadoxetic acid magnetic resonance for the diagnosis of hepatocellular carcinoma in newly detected nodules ≤2 cm in cirrhosis

BACKGROUND AND AIMS

Most of the published studies about the diagnostic accuracy of gadoxetic acid-enhanced magnetic resonance (EOB-MR) for the non-invasive diagnosis of hepatocellular carcinoma (HCC) have had a retrospective design. Thus, we aimed to prospectively evaluate the diagnostic accuracy of EOB-MR for the non-invasive diagnosis of HCC in nodules ≤2 cm detected by screening ultrasound (US) in patients with cirrhosis.

METHODS

Between July 2012 and October 2015, 62 consecutive asymptomatic Child-Pugh A-B cirrhotic patients with newly US-detected solitary nodules between 1 and 2 cm were prospectively included in the study. Hepatic extracellular contrast-enhanced MR (ECCE-MR) followed by EOB-MR were obtained in less than 1-month interval. Two independent radiologists blindly reviewed the EOB-MR studies, and the diagnosis of HCC was assigned when the lesion showed arterial enhancement followed by portal venous phase washout and/or hypointensity on the hepatobiliary phase (HBP). The final HCC diagnosis was made by ECCE-MR according to the accepted non-invasive criteria, or by biopsy in lesions with atypical vascular profile.

RESULTS

Final diagnoses were as follows: HCC (n = 41), intrahepatic cholangiocarcinoma (n = 2), colorectal metastases (n = 1) and benign conditions (n = 18). The sensitivity and specificity of EOB-MR for HCC diagnosis were 56.1% (95% CI: 39.7-71.5) and 90.5% (95% CI: 69.6-98.8), respectively, while sensitivity of ECCE-MR was 63.4% (95% CI: 46.9-77.9). The low rate of hypointense HCCs in the HBP and suboptimal liver uptake of contrast agent justify the low sensitivity of EOB-MR for HCC diagnosis.

CONCLUSION

EOB-MR does not surpass the diagnostic accuracy of ECCE-MR for non-invasive diagnosis of HCC in nodules ≤2 cm in cirrhotic patients.

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.

Magnetic resonance imaging features predictive of an incomplete response to transarterial chemoembolization in patients with hepatocellular carcinoma: A STROBE-compliant study

To identify pretreatment magnetic resonance imaging (MRI) features associated with an incomplete response (IR) to transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC).The medical records of 89 patients with HCC who had undergone a first TACE were reviewed retrospectively. The size, visual attenuation in the arterial phase, signal intensity (SI) on T1-, T2-, and diffusion-weighted images, and apparent diffusion coefficient (ADC) values of each lesion were evaluated on pretreatment images. The response to TACE was routinely assessed at 4 weeks post-treatment by 4-phase computed tomography. The HCC patients were classified as complete or incomplete responders based on the arterial-phase enhancement of the target lesion.In multivariate analysis, larger lesion diameter (P = .004, OR = 1.06 per millimeter, 95% CI = 1.02-1.11), faint enhancement on arterial phase (P = .021, OR = 3.24, 95% CI = 1.22-9.14), and non-low SI on T1-weighted images (P = .016, OR = 3.36, 95% CI = 1.29-9.32) were significantly associated with increased odds of an IR to TACE in HCC patients.An iso-to-high T1-weighted SI by pretreatment MRI was an independent predictor of an incomplete response to TACE in patients with HCC, in addition to faint arterial enhancement and lesion size.

Controversies in the management of hepatocellular carcinoma

The management of hepatocellular carcinoma (HCC) has evolved considerably over the last decade. Surveillance of cirrhotic patients and refinements to imaging techniques have enabled a relevant proportion of patients to be diagnosed at an early stage, when effective therapies are feasible. Resection, transplantation and ablation are all options in patients with early stage HCC. Thus, there is some controversy regarding which is the best treatment approach in challenging scenarios. There have also been major developments in locoregional therapies, particularly in intra-arterial approaches. Finally, the systemic treatment for HCC has changed dramatically following the demonstration of a survival benefit with sorafenib; there are currently several first-line (sorafenib and lenvatinib) and second-line (regorafenib, cabozantinib and ramucirumab) treatments that have shown a survival benefit. Expectations for immune checkpoint inhibitors are high, with the results of the ongoing phase III trials eagerly awaited. In this review we discuss some of the controversies in the management of HCC, focussing in particular on systemic therapy.

Hepatocellular Carcinoma: State of the Art Imaging and Recent Advances

The incidence of hepatocellular carcinoma (HCC) is increasing, with this trend expected to continue to the year 2030. Hepatocarcinogenesis follows a predictable course, which makes adequate identification and surveillance of at-risk individuals central to a successful outcome. Moreover, imaging is central to this surveillance, and ultimately to diagnosis and management. Many liver study groups throughout Asia, North America and Europe advocate a surveillance program for at-risk individuals to allow early identification of HCC. Ultrasound is the most commonly utilized imaging modality. Many societies offer guidelines on how to diagnose HCC. The Liver Image Reporting and Data System (LIRADS) was introduced to standardize the acquisition, interpretation, reporting and data collection of HCC cases. The LIRADS advocates diagnosis using multiphase computed tomography or magnetic resonance imaging (MRI) imaging. The 2017 version also introduces contrast-enhanced ultrasound as a novel approach to diagnosis. Indeed, imaging techniques have evolved to improve diagnostic accuracy and characterization of HCC lesions. Newer techniques, such as T1 mapping, intravoxel incoherent motion analysis and textural analysis, assess specific characteristics that may help grade the tumor and guide management, allowing for a more personalized approach to patient care. This review aims to analyze the utility of imaging in the surveillance and diagnosis of HCC and to assess novel techniques which may increase the accuracy of imaging and determine optimal treatment strategies.

LI-RADS for CT diagnosis of hepatocellular carcinoma: performance of major and ancillary features

PURPOSE

To evaluate the diagnostic performance of Liver Imaging Reporting and Data System (LI-RADS) v2017 major features, the impact of ancillary features, and categories on contrast-enhanced computed tomography (CECT) for the diagnosis of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This retrospective study included 59 patients (104 observations including 72 HCCs) with clinical suspicion of HCC undergoing CECT between 2013 and 2016. Two radiologists independently assessed major and ancillary imaging features for each liver observation and assigned a LI-RADS category based on major features only and in combination with ancillary features. The composite reference standard included pathology or imaging. Per-lesion estimates of diagnostic performance of major features, ancillary features, and LI-RADS categories were assessed by generalized estimating equation models.

RESULTS

Major features (arterial phase hyperenhancement, washout, capsule, and threshold growth) respectively had a sensitivity of 86.1%, 81.6%, 20.7%, and 26.1% and specificity of 39.3%, 67.9%, 89.9%, and 85.0% for HCC. Ancillary features (ultrasound visibility as discrete nodule, subthreshold growth, and fat in mass more than adjacent liver) respectively had a sensitivity of 42.6%, 50.8%, and 15.1% and a specificity of 79.2%, 66.9%, and 96.4% for HCC. Ancillary features modified the final category in 4 of 104 observations. For HCC diagnosis, categories LR-3, LR-4, LR-5, and LR-TIV (tumor in vein) had a sensitivity of 5.3%, 29.0%, 53.7%, and 10.7%; and a specificity of 49.1%, 84.4%, 97.3%, and 96.4%, respectively.

CONCLUSION

On CT, LR-5 category has near-perfect specificity for the diagnosis of HCC and ancillary features modifies the final category in few observations.

Lessons learnt from pathologic imaging correlation in the liver: an historical perspective

Imaging and pathology can be considered as two sides of the same diagnostic coin. Yet, pathology remains the gold-standard technique for the diagnosis of most diseases. Nevertheless, significant and constant progress in imaging has been made thanks to fruitful rad-path correlations. The aim of this article is to show how much imaging has benefited from pathology and to illustrate the different ways in which imaging has evolved according to different types of pathological references. Imaging of hepatocellular carcinoma shows how image-based knowledge and expertise can be exploited to yield a non-invasive diagnosis approaching that of a fixed, robust pathological reference. Hepatocellular adenomas provide an example of the constant radiological evolutions triggered by changing pathological definitions. Finally, hepatic steatosis illustrates the possibility for imaging to surpass its historical reference, and become a new gold-standard. For these three examples, we have taken a historical approach to demonstrate how rad-path interminglement creates knowledge.

Joint Consensus Statement of the Indian National Association for Study of the Liver and Indian Radiological and Imaging Association for the Diagnosis and Imaging of Hepatocellular Carcinoma Incorporating Liver Imaging Reporting and Data System

Hepatocellular carcinoma (HCC) is the 6th most common cancer and the second most common cause of cancer-related mortality worldwide. There are currently no universally accepted practice guidelines for the diagnosis of HCC on imaging owing to the regional differences in epidemiology, target population, diagnostic imaging modalities, and staging and transplant eligibility. Currently available regional and national guidelines include those from the American Association for the Study of Liver Disease (AASLD), the European Association for the Study of the Liver (EASL), the Asian Pacific Association for the Study of the Liver, the Japan Society of Hepatology, the Korean Liver Cancer Study Group, Hong Kong, and the National Comprehensive Cancer Network in the United States. India with its large population and a diverse health infrastructure faces challenges unique to its population in diagnosing HCC. Recently, American Association have introduced a Liver Imaging Reporting and Data System (LIRADS, version 2017, 2018) as an attempt to standardize the acquisition, interpretation, and reporting of liver lesions on imaging and hence improve the coherence between radiologists and clinicians and provide guidance for the management of HCC. The aim of the present consensus was to find a common ground in reporting and interpreting liver lesions pertaining to HCC on imaging keeping LIRADSv2018 in mind.

Intention-to-treat analysis of liver transplantation, resection and thermal ablation for hepatocellular carcinoma in a single centre

BACKGROUND

potentially curative treatment options for hepatocellular carcinoma (HCC) include liver transplantation (LT), liver resection (LR) and thermal ablation (TA). Long term intent-to-treat (ITT) analysis from a single-centre using all three modalities contemporaneously has not been published.

METHODS

An ITT analysis was undertaken of all patients with HCC listed for LT, or have undergone LR or TA.

RESULTS

444 patients were identified; 145 were listed for LT (121 underwent LT), 190 underwent LR and 109 underwent TA. One and 3-year overall survival (OS) was similar among LT, LR and TA (88/77%, 88/64% and 95/72%) whereas 5-year OS was higher following LT than LR or TA (73% vs. 54% vs. 49%). Disease-free survival at 1- and 5-years was higher for LT (97% and 84%) than LR (66% and 35%) or TA (73%, and 19%).

CONCLUSION

LT offered the lowest rate of cancer recurrence and highest chance of long-term survival. Differences in outcome likely reflect a combination of cancer-related factors (AFP, micro- and macrovascular invasion), patient-related factors (performance status, co-morbidities and psychosocial issues) and treatment type. Two thirds of patients treated by LR and three quarters treated by TA had HCC recurrence by 5 years, reinforcing the need for close long-term surveillance.

Transcatheter arterial chemoembolization combined with radiofrequency or microwave ablation for hepatocellular carcinoma: a review

Hepatocellular carcinoma (HCC) is the sixth most common type of malignancy. Several therapies are available for HCC and are determined by stage of presentation, patient clinical status and liver function. Local–regional treatment options, including transcatheter arterial chemoembolization, radiofrequency ablation or microwave ablation, are safe and effective for HCC but are accompanied by limitations. The synergistic effects of combined transcatheter arterial chemoembolization and radiofrequency ablation/microwave ablation may overcome these limitations and improve the therapeutic outcome. The purpose of this article is to review the current literature on these combined therapies and examine their efficacy, safety and influence on the overall and recurrence-free survival in patients with HCC.

Liver Imaging Reporting and Data System (LI-RADS) Version 2018: Imaging of Hepatocellular Carcinoma in At-Risk Patients

The Liver Imaging Reporting and Data System (LI-RADS) is composed of four individual algorithms intended to standardize the lexicon, as well as reporting and care, in patients with or at risk for hepatocellular carcinoma in the context of surveillance with US; diagnosis with CT, MRI, or contrast material-enhanced US; and assessment of treatment response with CT or MRI. This report provides a broad overview of LI-RADS, including its historic development, relationship to other imaging guidelines, composition, aims, and future directions. In addition, readers will understand the motivation for and key components of the 2018 update.

Multimodality treatment of hepatocellular carcinoma: How field practice complies with international recommendations

BACKGROUND

Management of hepatocellular carcinoma (HCC) is framed within standardized protocols released by Scientific Societies, whose applicability and efficacy in field practice need refining.

AIM

We evaluated the applicability and effectiveness of guidelines for the treatment of HCC of the American Association for the Study of the Liver (AASLD).

METHODS

370 consecutive cirrhotic patients with de novo HCC in different stages, 253 BCLC A, 66 BCLC B, 51 BCLC C received treatment through a multidisciplinary team (MDT) decision and were followed until death or end of follow-up.

RESULTS

Treatment was adherent to AASLD recommendations in 205 (81%) BCLC A patients, 36 (54%) BCLC B, and 27 (53%) BCLC C. Radiological complete response was achieved in 165 (45%) patients after the first-line treatment, in 22 (19%) after a second-line and in 9 (23%) after a third-line treatment. Adherence to AASLD recommendation allowed a lower yearly mean mortality rate in BCLC A patients compared with other treatment (5.0% vs 10.4% P = .004), whereas upward treatment stage migration compared with the standard of care was associated with reduced yearly mortality in BCLC B (8.6% vs 20.7%, P = .029) and BCLC C (42.6% vs 59.0%, P = .04) patients.

CONCLUSIONS

HCC multimodality treatment including other than first-line therapy is common in clinical practice and impact on the achievement of complete response. Personalized treatment was able to provide survival benefits to patients whose profile is not accounted for by international recommendations, which need to be amended.

Role of Imaging in Surveillance and Diagnosis of Hepatocellular Carcinoma

The prognosis for hepatocellular carcinoma (HCC) is dependent on tumor stage at diagnosis, with curative treatment options more available to early-detected HCCs. Professional organizations have produced HCC screening guidelines in at-risk groups, with ultrasound the most commonly used screening tool and increased interest in MRI in specific populations. HCC may be diagnosed by imaging features alone and have been universally incorporated into management guidelines. The radiology community has standardized imaging criteria for HCC with the development of the Liver Imaging Reporting and Data System, which has expanded to incorporate computed tomography, MR, and contrast-enhanced ultrasound for diagnostic purposes.

Non-alcoholic fatty liver disease-associated hepatocellular carcinoma: effect of hepatic steatosis on major hepatocellular carcinoma features at MRI

OBJECTIVE:

To evaluate the effect of hepatic steatosis on LI-RADS® major features at MRI in patients with non-alcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC).

METHODS:

HCC and liver parenchyma features at MRI from 48 consecutive patients with NAFLD and histology proven HCC (mean ± SD; 4.5 ± 3.4 cm) were independently reviewed by three radiologists. Inter-rater agreement was determined by prevalence/bias-adjusted kappa. Hepatic fat signal fraction (FS%) was independently calculated. HCC features were compared by FS% at MRI using logistic regression analysis and histologic steatosis grade using Cochran-Armitage test for trend, stratified by cirrhotic liver morphology or histologic fibrosis stage. Receiver operating characteristic curves were generated to determine the sensitivity and specificity for major HCC features by FS%.

RESULTS:

Major HCC features included arterial phase hyperenhancement (APHE) in 45 (93%), portal venous phase washout (PVWO) in 30 (63%), delayed phase washout (DPWO) in 38 (79%) and enhancing "capsule" in 34 (71%). Cirrhotic morphology was present in 22 (46%). Inter-rater agreement was 0.75 for APHE, 0.42-0.58 for PVWO, 0.58-0.71 for DPWO and 0.38-0.67 for enhancing "capsule". There was an 18%, 14% and 22% increase in the odds of absent PVWO, DPWO and capsule appearance for every 1% increase in hepatic FS% in patients with non-cirrhotic liver morphology (p = 0.011, 0.040 and 0.029, respectively). Hepatic FS% ≥ 14.8% had a sensitivity and specificity of 64 and 100% for absent PVWO and 71 and 90% for absent DPWO in patients with non-cirrhotic liver morphology.

CONCLUSION:

Absent washout and capsule appearance are associated with increasing hepatic steatosis in patients with non-cirrhotic, NAFLD-associated HCC.

ADVANCES IN KNOWLEDGE:

In patients with non-cirrhotic, non-alcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC), absent HCC washout and capsule appearance are associated with increasing hepatic steatosis, thereby potentially impacting the noninvasive imaging diagnosis of HCC in these patients. Lack of washout or capsule appearance in steatotic livers at MRI may require alternative criteria for the diagnosis of HCC in patients with non-cirrhotic NAFLD.

Added Value of sequentially performed gadoxetic acid-enhanced liver MRI for the diagnosis of small (10-19 mm) or atypical hepatic observations at contrast-enhanced CT: A prospective comparison

BACKGROUND

Small hepatocellular carcinomas (HCCs) often show atypical features at cross-sectional imaging, yet there is no preferred recommendation for the diagnosis or characterization of small observations (10-19 mm) at present.

PURPOSE

To determine the added value of sequentially performed gadoxetic acid-enhanced liver MRI for contrast-enhanced computed tomography (CECT)-detected small (10-19 mm) or atypical hepatic observations ≥20 mm in the diagnosis of HCC.

STUDY TYPE

Prospective, cross-sectional, intraindividual comparison.

POPULATION

In all, 110 patients at high risk of developing HCC.

FIELD STRENGTH/SEQUENCE

1.5T and 3T/T₁ -weighted imaging.

ASSESSMENT

Hepatic observations were classified into HCCs or benign non-HCCs based on imaging features of arterial phase hyperenhancement (APHE) and portal or delayed washout at CT or APHE and portal washout at MRI. Final diagnoses were established using a composite algorithm and diagnostic performances of MRI and CT were compared in all observations. In addition, in a subgroup of histologically confirmed observations and stable benign observations during follow-up (n = 94), sensitivity and specificity of MRI were compared between the aforementioned criteria and LR-5 of Liver Imaging Reporting and Data System v2014.

STATISTICAL TEST

χ² test.

RESULTS

MRI provided higher sensitivity than CT (62.2% vs. 27.0%, P = 0.0001) while maintaining specificity (97.2%, each) at the per-patient level. Among 124 observations, 10-19 mm in size, MRI showed significantly higher sensitivity in diagnosing HCCs (62.5%, 50/80) than CT (25%, 20/80, P < 0.0001) with comparable specificity (97.7% [43/44], each). However, seven atypical observations (≥20 mm) at CT remained atypical at MRI. In the subgroup analysis, the diagnostic criteria of APHE and portal washout showed a significantly higher sensitivity (44.2%, 19/43) than LR-5 (23.2%, 10/43, P = 0.004), without compromising specificity (97.7% vs. 95.5%).

DATA CONCLUSION

Sequentially performed gadoxetic acid-enhanced MRI provided added value to CECT for the diagnosis of HCCs in small observations by improving sensitivity while maintaining specificity.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:574-587.

Persistence of hepatocellular carcinoma risk in hepatitis C patients with a response to IFN and cirrhosis regression

BACKGROUND AND AIM

In patients with HCV-related cirrhosis, a sustained virological response may lead to cirrhosis regression. Whether histological changes translate into prevention of long-term complications, particularly hepatocellular carcinoma is still unknown. This was investigated in a cohort of histological cirrhotics who had been prospectively followed-up for 10 years after the achievement of a sustained virological response to IFN.

METHODS

In all, 38 sustained virological response cirrhotics who underwent a liver biopsy 5 years post-SVR were prospectively followed to assess the impact of cirrhosis regression on clinical endpoints.

RESULTS

During a follow-up of 86 (30-96) months from liver biopsy, no patients developed clinical decompensation, whilst 5 (13%) developed hepatocellular carcinoma after 79 (7-88) months. The 8-year cumulative probability of hepatocellular carcinoma was 17%, without differences between patients with or without cirrhosis regression (19% [95% CI 6%-50%] vs 14% [95% CI 4%-44%], P = .88). Patients who developed or did not an hepatocellular carcinoma had similar rates of residual cirrhosis (P = 1.0), collagen content (P = .48), METAVIR activity (P = .34), portal inflammation (P = .06) and steatosis (P = .17). At baseline, patients who developed an hepatocellular carcinoma had higher γGT (HR 1.03, 95% CI 1.00-1.06; P = .014) and glucose (HR 1.02, 95% CI 1.00-1.02; P = .012) values; moreover, they had increased Forns Score (HR 12.8, 95% CI 1.14-143.9; P = .039), Lok Index (HR 6.24, 95% CI 1.03-37.6; P = .046) and PLF (HR 19.3, 95% CI 1.72-217.6; P = .016) values. One regressor died of lung cancer. The 8-year cumulative survival probability was 97%, independently on cirrhosis regression (96% vs 100%, P = 1.0) or hepatocellular carcinoma (100% vs 97%, P = 1.0).

CONCLUSIONS

Post-SVR cirrhosis regression does not prevent hepatocellular carcinoma occurrence.

Acoustic Characterization and Enhanced Ultrasound Imaging of Long-Circulating Lipid-Coated Microbubbles

OBJECTIVES

A long-circulating lipid-coated ultrasound (US) contrast agent was fabricated to achieve a longer wash-out time and gain more resistance against higher-mechanical index sonication. Systemic physical, acoustic, and in vivo imaging experiments were performed to better understand the underlying mechanism enabling the improvement of contrast agent performance by adjusting the physical and acoustic properties of contrast agent microbubbles.

METHODS

By simply altering the gas core, a kind of US contrast agent microbubble was synthesized with a similar lipid-coating shell as SonoVue microbubbles (Bracco SpA, Milan, Italy) to achieve a longer wash-out time and higher inertial cavitation threshold. To bridge the structure-performance relationship of the synthesized microbubbles, the imaging performance of the microbubbles was assessed in vivo with SonoVue as a control group. The size distribution and inertial cavitation threshold of the synthesized microbubbles were characterized, and the shell parameters of the microbubbles were determined by acoustic attenuation measurements. All of the measurements were compared with SonoVue microbubbles.

RESULTS

The synthesized microbubbles had a spherical shape, a smooth, consistent membrane, and a uniform distribution, with an average diameter of 1.484 μm. According to the measured attenuation curve, the synthesized microbubbles resonated at around 2.8 MHz. Although the bubble's shell elasticity (0.2 ± 0.09 N/m) was comparable with SonoVue, it had relatively greater viscosity and inertial cavitation because of the different gas core. Imaging studies showed that the synthesized microbubbles had a longer circulation time and a better chance of fighting against rapid collapse than SonoVue.

CONCLUSIONS

Nano/micrometer long-circulating lipid-coated microbubbles could be fabricated by simply altering the core composition of SonoVue microbubbles with a higher-molecular weight gas. The smaller diameter and higher inertial cavitation threshold of the synthesized microbubbles might make it easier to access deep-seated organs and give prolonged imaging enhancement in the liver.

LI-RADS for MR Imaging Diagnosis of Hepatocellular Carcinoma: Performance of Major and Ancillary Features

Purpose To evaluate the performance of major features, ancillary features, and categories of Liver Imaging Reporting and Data System (LI-RADS) version 2014 at magnetic resonance (MR) imaging for the diagnosis of hepatocellular carcinoma (HCC). Materials and Methods This retrospective institutional review board-approved study included patients with liver MR imaging and at least one pathologically proved lesion. Between 2004 and 2016, 102 patients (275 observations including 113 HCCs) met inclusion criteria. Two radiologists independently assessed major and ancillary imaging features for each liver observation and assigned a LI-RADS category. Per-lesion estimates of diagnostic performance of major features, ancillary features, and LI-RADS categories were assessed by using generalized estimating equation models. Results Major features (arterial phase hyperenhancement, washout, capsule, and threshold growth) had a sensitivity of 88.5%, 60.6%, 32.9%, and 41.6%, and a specificity of 18.6%, 84.8%, 98.8%, and 83.2% for HCC, respectively. Ancillary features (mild-moderate T2 hyperintensity, restricted diffusion, mosaic architecture, intralesional fat, lesional fat sparing, blood products, and subthreshold growth) had a sensitivity of 62.2%, 54.8%, 9.9%, 30.9%, 23.1%, 2.8%, and 48.3%, and a specificity of 79.4%, 90.6%, 99.4%, 94.2%, 83.1%, 99.3%, and 91.4% for HCC, respectively. The LR-5 or LR-5 V categories had a per-lesion sensitivity of 50.8% and a specificity of 95.8% for HCC, respectively. The LR-4, LR-5, or LR-5 V categories (determined by using major features only vs combination of major and ancillary features) had a per-lesion sensitivity of 75.9% and 87.9% and a per-lesion specificity of 87.5% and 86.2%, respectively. Conclusion The use of ancillary features in combination with major features increases the sensitivity while preserving a high specificity for the diagnosis of HCC.

LI-RADS 2017: An update

The computed tomography / magnetic resonance imaging (CT/MRI) Liver Imaging Reporting & Data System (LI-RADS) is a standardized system for diagnostic imaging terminology, technique, interpretation, and reporting in patients with or at risk for developing hepatocellular carcinoma (HCC). Using diagnostic algorithms and tables, the system assigns to liver observations category codes reflecting the relative probability of HCC or other malignancies. This review article provides an overview of the 2017 version of CT/MRI LI-RADS with a focus on MRI. The main LI-RADS categories and their application will be described. Changes and updates introduced in this version of LI-RADS will be highlighted, including modifications to the diagnostic algorithm and to the optional application of ancillary features. Comparisons to other major diagnostic systems for HCC will be made, emphasizing key similarities, differences, strengths, and limitations. In addition, this review presents the new Treatment Response algorithm, while introducing the concepts of MRI nonviability and viability. Finally, planned future directions for LI-RADS will be outlined.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;47:1459-1474.

Practical advantages of contrast-enhanced ultrasound in abdominopelvic radiology

Computed tomography (CT) and magnetic resonance imaging (MRI) are two of the workhorse modalities of abdominopelvic radiology. However, these modalities are not without patient- and technique-specific limitations that may prevent a timely and accurate diagnosis. Contrast-enhanced ultrasound (CEUS) is an effective, rapid, and cost-effective imaging modality with expanding clinical utility in the United States. In this pictorial essay, we provide a case-based discussion demonstrating the practical advantages of CEUS in evaluating a variety of pathologies in which CT or MRI was precluded or insufficient. Through these advantages, CEUS can serve a complementary role with CT and MRI in comprehensive abdominopelvic radiology.

Hepatocellular carcinoma

Hepatocellular carcinoma appears frequently in patients with cirrhosis. Surveillance by biannual ultrasound is recommended for such patients because it allows diagnosis at an early stage, when effective therapies are feasible. The best candidates for resection are patients with a solitary tumour and preserved liver function. Liver transplantation benefits patients who are not good candidates for surgical resection, and the best candidates are those within Milan criteria (solitary tumour ≤5 cm or up to three nodules ≤3 cm). Image-guided ablation is the most frequently used therapeutic strategy, but its efficacy is limited by the size of the tumour and its localisation. Chemoembolisation has survival benefit in asymptomatic patients with multifocal disease without vascular invasion or extrahepatic spread. Finally, sorafenib, lenvatinib, which is non-inferior to sorafenib, and regorafenib increase survival and are the standard treatments in advanced hepatocellular carcinoma. This Seminar summarises the scientific evidence that supports the current recommendations for clinical practice, and discusses the areas in which more research is needed.

Contrast ultrasound LI-RADS LR-5 identifies hepatocellular carcinoma in cirrhosis in a multicenter restropective study of 1,006 nodules

BACKGROUND & AIMS

The use of contrast enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis was questioned because of the risk of a false positive diagnosis in cases of cholangiocarcinoma. The American College of Radiology has recently released a scheme (CEUS Liver Imaging Reporting and Data System [LI-RADS®]) to classify lesions at risk of HCC investigated by CEUS. The aim of the present study was to validate this LI-RADS scheme for the diagnosis of HCC.

METHODS

A total of 1,006 nodules from 848 patients with chronic liver disease at risk of HCC were collected in five Italian centers and retrospectively analyzed. Nodules were classified as LR-5, (HCC) if ≥1 cm with arterial phase hyperenhancement, and late washout (onset ≥60 s after contrast injection) of mild degree. Rim enhancement and/or early and/or marked washout qualified lesions as LR-M (malignant, but not specific for HCC). Other combinations qualified lesions at intermediate risk for HCC (LR-3) or probable HCC (LR-4). Diagnostic reference standard was CT/MRI diagnosis of HCC (n = 506) or histology (n = 500).

RESULTS

The median nodule size was 2 cm. Of 1,006 nodules, 820 (81%) were HCC, 40 (4%) were cholangiocarcinoma, 116 (11%) regenerative nodules (±dysplastic). The LR-5 category (52% of all nodules) was 98.5% predictive of HCC, with no risk of misdiagnosis for pure cholangiocarcinoma. Sensitivity for HCC was 62%. All LR-M nodules were malignant and the majority of non-hepatocellular origin. Over 75% of cholangiocarcinomas were LR-M. The LR-3 category included 203 lesions (HCC 96 [47%]) and the LR-4 202 (HCC 173 [87%]).

CONCLUSIONS

The CEUS LI-RADS class LR-5 is highly specific for HCC, enabling its use for a confident non-invasive diagnosis.

LAY SUMMARY

This is a retrospective study of approximately 1,000 focal lesions at risk for hepatocellular carcinoma (HCC). Herein, we demonstrate that the refined definition of the typical contrast enhanced ultrasound pattern of HCC introduced by the Liver Imaging Reporting and Data System (LI-RADS®) practically abolishes the risk of misdiagnosis of other malignant entities (e.g. cholangiocarcinoma) for HCC with negligible reduction in sensitivity. These data support the use of contrast enhanced ultrasound to diagnose HCC in cirrhosis.

Impact of resection and ablation for single hypovascular hepatocellular carcinoma ≤2 cm analysed with propensity score weighting

BACKGROUND AND AIMS

Small hypovascular hepatocellular carcinoma (HCC) ≤2 cm is biologically less aggressive than hypervascular one, however, the optimal treatment is still undetermined. The efficacy of surgical resection (SR), radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) was evaluated.

METHODS

The 853 (SR, 176; RFA, 491; PEI, 186) patients were enrolled who met Child-Pugh A/B, single hypovascular HCC ≤2 cm pathologically proven, available tumour differentiation and absence of macrovascular invasion and extrahepatic metastasis. Overall and recurrence-free survivals were compared in original and a propensity score weighted pseudo-population with 732 patients.

RESULTS

The median follow-up time and tumour size were 2.8 years and 1.47 cm respectively. In original population, multivariate Cox regression showed no significant difference for overall survival among three groups. In pseudo-population, Cox regression also revealed no significant difference for overall survival among them, although SR (HR, 0.56; 95% CI, 0.36-0.86) and RFA (HR, 0.75; 95% CI, 0.57-1.00) groups had significantly lower recurrence than PEI group. The overall survival rates at 3 and 5 years for the SR, RFA and PEI groups were 94%/70%, 90%/75% and 94%/73% respectively. Corresponding recurrence-free survival rates were 64%/54%, 59%/41% 48%/33% respectively. Subgroup analysis revealed no significant survival benefit of SR compared with non-SR. No treatment-related death occurred.

CONCLUSIONS

For patients with single hypovascular HCC ≤2 cm, no significant difference for overall survival was first identified among 3 treatment groups. The SR or RFA could be recommended, and PEI would be alternative to RFA.