US LI-RADS: ultrasound liver imaging reporting and data system for screening and surveillance of hepatocellular carcinoma

Applicability of multiple quantitative ultrasound liver biomarkers in children and adolescents with severe obesity

BACKGROUND

Obesity is associated with chronic liver disease, which is why improved non-invasive diagnostic assessment of liver affection is desirable. The ultrasound-based biomarkers Attenuation Imaging coefficient (ATI), Shear Wave Elastography (SWE), and Shear Wave Dispersion (SWD) have the potential to assess liver steatosis, fibrosis and inflammation/oedema respectively. The aim was therefore to evaluate the feasibility of applying ultrasound-based liver biomarkers in children and adolescents with severe obesity.

METHODS

Ultrasound was performed, before treatment, in 56 patients with childhood obesity (< 18 years) referred for bariatric surgery or treatment with glucagon-like peptide-1 receptor agonists. An ultrasound visualisation score (A: no limitations - D: severe limitations) was used. ATI, SWE and SWD were measured, irrespective of visualisation score, and compared to clinical data, serological measures and depth of measurement. Scan-rescan reproducibility measurements were performed, both for continuous measures using intraclass correlation coefficient (ICC) and for kappa coefficient using proposed reference thresholds for elevated/pathological values in children during fasting and free-breathing: > ATI 0.56 dB/cm/MHz, > SWE 4.9 kPa and > SWD 11.9 (m/s)/kHz.

RESULTS

The median (min-max) age of the 56 patients (51.8% male) was 16.2 years (9.9; 18) and the median BMI standard deviation score (SDS) was 4.4 (2.7; 7.3). The distribution of the visibility score was A 5.5%, B 50%, C 41% and D 3.5%. The median (min-max) ATI, SWE and SWD values were 0.58 dB/cm/MHz (0.32; 0.97), 7.2 kPa (4.3; 19.6) and 14.3 (m/s)/kHz (8.9; 24.3) respectively. Both ATI (β = -4.2; r2 = 0.3; p < 0.0001) and SWD (β = 0.14; r2 = 0.17; p = 0.0033) were influenced by depth of measurement. A weak association was found between ATI and serum triglycerides (β = 0.07; r2 = 0.12; p = 0.015). SWE was associated with BMI-SDS (β = 0.71; r2 = 0.09; p = 0.035). No other significant associations were found. ICC was moderate for ATI (0.61), fair for SWE (0.46) and fair for SWD (0.51). Kappa coefficient was substantial for ATI (0.77), excellent for SWE (1.0) and moderate for SWD (0.53).

CONCLUSION

When accounting for visualization score, multiple ultrasound liver biomarkers appear applicable in most children and adolescents with severe obesity. Median ATI, SWE and SWD values were all increased, compared to currently known paediatric normal values. However, median ATI was likely underestimated due to depth dependence of measurement. Although caution is advised in clinical decision-making due to fair-moderate reproducibility between scans, most importantly, the biomarkers appear capable of differentiating between non-affected and affected liver in children with severe obesity.

Multicenter evaluation of abbreviated MRI and ultrasound for detecting early-stage hepatocellular carcinoma

Background & aims

Abbreviated MRI (AMRI) has been proposed as an alternative to ultrasound for hepatocellular carcinoma (HCC) surveillance; however, comparative data for AMRI and ultrasound are needed. Thus, we evaluated the sensitivity and specificity of dynamic contrast-enhanced (DCE)-AMRI and ultrasound for early-stage HCC detection in patients with cirrhosis.

Methods

We conducted a multicenter retrospective case-control study among patients with cirrhosis (cases with early-stage HCC as per Milan Criteria; controls without HCC) who underwent an ultrasound and a DCE-MRI within a 6-month period between 2012 and 2019. HCC diagnosis was confirmed by imaging alone in 85% and by histopathology in 15% of patients. Dynamic AMRI examinations were simulated from the full MRI by selecting relevant sequences. Independent, blinded interpretations of ultrasounds and AMRI results were performed using Liver Imaging Reporting and Data System algorithms. Ultrasounds were considered positive if US-3 observations were detected. AMRI was considered positive if LR-4, LR-5, or LR-M were detected. Per-patient sensitivity and specificity for early-stage HCC detection were estimated, and cross-modality differences were tested.

Results

We included 216 cases and 432 controls. Patient-level sensitivity and specificity of AMRI were significantly higher compared with ultrasound: 80.1% (95% CI 76.1-83.6) vs. 71.1% (95% CI 66.6-75.2), p <0.001, and 91.9% (95% CI 89.9-93.5) vs. 72.3% (95% CI 69.3-75.2), p <0.001, respectively. AMRI sensitivity was significantly higher compared with ultrasound among patients with Child-Pugh B cirrhosis (80.8% vs. 57.4%, p <0.001) but not among those with Child-Pugh A (84.7% vs. 78.6%, p = 0.07) or Child-Pugh C cirrhosis (52.6% vs. 68.4%, p = 0.18).

Conclusions

Dynamic AMRI may be more sensitive and specific for early-stage HCC detection in patients with cirrhosis compared with ultrasound, although its relative benefit might be smaller in patients with Child-Pugh A cirrhosis. Larger direct comparative data sets are needed, particularly among patients with Child-Pugh C cirrhosis who may benefit from alternative surveillance strategies.

Impact and implications

Abbreviated MRI (AMRI) is increasingly recognized as an alternative to ultrasound for hepatocellular carcinoma (HCC) surveillance. However, existing data are limited by single-center samples, spectrum bias, and lack of comparative data for AMRI vs. ultrasound. We found that AMRI had significantly higher per-patient sensitivity and specificity compared with ultrasound for the detection of early-stage HCC, although its relative benefit might be smaller in patients with Child-Pugh A cirrhosis, and both modalities underperformed in patients with Child-Pugh C cirrhosis. If sufficiently validated, AMRI could be adopted into practice guidelines for HCC surveillance and serve as a preferred alternative in select subgroups of patients.

Exam quality of ultrasound and dynamic contrast-enhanced abbreviated MRI and impact on early-stage HCC detection

PURPOSE

MRI is a potential alternative to ultrasound for hepatocellular carcinoma (HCC) detection. We evaluated the impact of ultrasound and dynamic abbreviated MRI (AMRI) exam quality on early-stage HCC detection.

METHODS

We conducted a multicenter case-control study among patients with cirrhosis (cases with early-stage HCC per Milan Criteria; controls without HCC) who underwent both a liver ultrasound and dynamic contrast-enhanced (DCE) AMRI within 6 months in 2012-2019. Two radiologists performed independent, blinded interpretations of both exams for HCC detection and scored exam quality as no/mild, moderate, or severe limitations. Associations between exam quality, patient characteristics, and HCC detection were assessed by odds ratios (OR).

RESULTS

Of 216 cases and 432 controls, severe limitations were reported in 7% and 8% of ultrasounds and DCE-AMRIs, respectively. Severe limitations at ultrasound were associated with obesity (OR 2.08, 95%CI [1.32-3.32]) and metabolic dysfunction-associated steatotic liver disease (MASLD) (OR 1.98 [1.12-3.44]) but not for DCE-AMRI. Decompensated cirrhosis (Child-Pugh C) was associated with severe limitations for both ultrasound (OR 2.54 [1.37-4.58]) and DCE-AMRI (OR 3.96 [2.36-6.58]). Compared to exams with no/mild limitations, exams with severe limitations had lower sensitivity for ultrasound (79.6% vs. 21.7%, P < 0.001) and AMRI (86.1% vs. 50.0%, P = 0.001). In patients in whom ultrasound was severely limited, DCE-AMRI had significantly higher odds of early-stage HCC detection than ultrasound (OR 8.23 [1.25-54.02]).

CONCLUSIONS

HCC detection by DCE-AMRI may be preferred in patients with severe limitations at ultrasound due to obesity and MASLD. Both modalities remain limited for patients with decompensated cirrhosis, for whom alternative strategies may be needed.

Ultrasound shear wave viscoelastography to characterize liver nodules

Purpose. To investigate the diagnostic performance of ultrasound (US)-based shear wave speed (SWS), shear wave attenuation (SWA), and combination of them as shear wave viscoelastography (SWVE) methods in patients undergoing US to characterize focal liver nodules.Materials and methods. In this prospective cross-sectional study, 70 patients with 72 nodules were enrolled. Investigational US and clinical magnetic resonance imaging (MRI) examinations were performed in all participants. The composite reference standard included MRI or histopathology to differentiate benign and malignant nodules. A linear discriminant analysis (LDA) was used to assess the combination of SWVE methods. Analyzes included Mann-WhitneyUtest, receiver operating characteristic analysis, and computation of sensitivity and specificity at the point that maximized the Youden index.Results. Mean SWS was significantly higher in malignant than benign nodules (2.49 ± 0.76 m s-1vs. 1.72 ± 0.70,p< 0.001), whereas SWA was lower (0.56 ± 0.30 vs. 1.10 ± 0.43 Np/m/Hz,p< 0.001). To differentiate between malignant and benign nodules, SWS with a threshold of 2.43 m s-1achieved a sensitivity of 0.54 (95% confidence interval (CI): 0.38-0.69) and a specificity of 0.88 (CI: 0.74-0.95). SWA with a threshold of 0.81 Np/m/Hz yielded a sensitivity of 0.81 (CI: 0.66-0.90) and a specificity of 0.74 (CI: 0.58-0.86). Combining these SWVE methods using a LDA resulted in a sensitivity of 0.81 (CI: 0.66-0.91) and a specificity of 0.86 (CI: 0.71-0.94).Conclusion. Malignant nodules had higher SWS and lower SWA than benign ones. The combination of SWS and SWA in a LDA classification algorithm increased the diagnostic performance.

Recent advances and issues in imaging modalities for hepatocellular carcinoma surveillance

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. Early detection via surveillance plays a crucial role in enabling curative treatment and improving survival rates. Since the initial randomized controlled trial, biannual ultrasound (US) has been established as the standard surveillance method because of its accessibility, safety, and low cost. However, US has some limitations, including operator dependency, suboptimal sensitivity for early-stage HCC, and challenges such as a limited sonic window that may result in inadequate examination. Alternative imaging modalities, including contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), have demonstrated higher sensitivity for detecting very early-stage HCC. Recent advancements, such as low-dose CT with deep learning-based reconstruction, have enhanced the safety and feasibility of CT-based surveillance by reducing radiation exposure and amount of contrast media. MRI, particularly with gadoxetic acid or abbreviated protocols, offers superior tissue contrast and sensitivity, although its accessibility and cost remain challenges. Tailored surveillance strategies based on individual risk profiles and integration of advanced imaging technologies have the potential to enhance the detection performance and cost-effectiveness. This review highlights the recent developments in imaging technologies for HCC surveillance, focusing on their respective strengths and limitations.

US Liver Imaging Reporting and Data System Version 2017: A Systematic Review and Meta-Analysis

Background The US Liver Imaging Reporting and Data System (LI-RADS) includes an assessment category (US-1, negative; US-2, subthreshold; and US-3, positive) and a visualization score reflecting image quality (VIS-A, no or minimal limitations; VIS-B, moderate limitations; and VIS-C, severe limitations). The US-3 and VIS-C impact patient treatment. Purpose To establish the distributions of categories and visualization scores, estimate the proportions of hepatocellular carcinoma (HCC) and overall malignancy in the US-3 category, and identify variables associated with the VIS-C score by conducting a meta-analysis. Materials and Methods A systematic search of articles published between January 1, 2017, and September 17, 2023, identified studies reporting distributions of US LI-RADS version 2017 categories or visualization scores. Characteristics of the study design, patient cohorts, and outcomes of interest (distributions of US categories and visualization scores, percentages of probable or definite HCC and malignancy in US-3 category, and variables associated with VIS-C) were extracted. For the meta-analysis, estimates were established with random-effects models. Results Fifteen studies comprising 39 166 US examinations were included. Of all examinations, 89.7% (95% CI: 86.8, 91.8) were categorized US-1; 4.4% (95% CI: 2.8, 6.2), US-2; and 5.9% (95% CI: 4.1, 8.0), US-3. Of the US-3 examinations, 25.9% (95% CI: 17.1, 34.7) had probable or definite HCC and 26.4% (95% CI: 18.4, 34.5) had overall malignancy. Among all examinations, 59.7% (95% CI: 46.9, 67.8) were assigned VIS-A; 32.5% (95% CI: 21.9, 41.6), VIS-B; and 7.8% (95% CI: 2.8, 14.3), VIS-C. Obesity (odds ratio [OR], 2.37; 95% CI: 1.57, 3.59), nonalcoholic fatty liver disease (NAFLD) (OR, 2.24; 95% CI: 1.64, 3.06), and Child-Pugh B or C (OR, 2.41; 95% CI: 1.43, 4.06) were associated with VIS-C score. Conclusion Overall, 90% of surveillance US results were negative (US-1), and 92% were of adequate quality (VIS-A or VIS-B); 26% of patients with US-3 results had HCC. VIS-C was associated with obesity, NAFLD, and cirrhosis. Systemic review registry no. CRD42022384925 © RSNA, 2025 Supplemental material is available for this article.

The Diagnosis and Staging of Hepatocellular Carcinoma: A Review of Current Practices

Promoting the early detection and diagnosis of hepatocellular carcinoma (HCC) is a critical strategy to improve patient outcomes as this can lead to greater access to curative treatments. This review highlights the diagnostic tests for HCC, including the use of the Liver Imaging Reporting and Data System systems and histopathology. Staging is essential for informing prognosis and guiding treatment decisions; this review also covers a widely used and well-validated staging system called the Barcelona-Clinic Liver Cancer (BCLC) algorithm. The BCLC incorporates tumor status, liver function, and patient performance to stage patients with newly diagnosed HCC.

EASL Clinical Practice Guidelines on the management of hepatocellular carcinoma

Liver cancer is the third leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) accounting for approximately 90% of primary liver cancers. Advances in diagnostic and therapeutic tools, along with improved understanding of their application, are transforming patient treatment. Integrating these innovations into clinical practice presents challenges and necessitates guidance. These clinical practice guidelines offer updated advice for managing patients with HCC and provide a comprehensive review of pertinent data. Key updates from the 2018 EASL guidelines include personalised surveillance based on individual risk assessment and the use of new tools, standardisation of liver imaging procedures and diagnostic criteria, use of minimally invasive surgery in complex cases together with updates on the integrated role of liver transplantation, transitions between surgical, locoregional, and systemic therapies, the role of radiation therapies, and the use of combination immunotherapies at various stages of disease. Above all, there is an absolute need for a multiparametric assessment of individual risks and benefits, considering the patient's perspective, by a multidisciplinary team encompassing various specialties.

Inter-reader reliability of Ovarian-Adnexal Reporting and Data System US: a systematic review and meta-analysis

PURPOSE

Ovarian-Adnexal Reporting and Data System (O-RADS) US provides a standardized lexicon for ovarian and adnexal lesions, facilitating risk stratification based on morphological features for malignancy assessment, which is essential for proper management. However, systematic determination of inter-reader reliability in O-RADS US categorization remains unexplored. This study aimed to systematically determine the inter-reader reliability of O-RADS US categorization and identify the factors that affect it.

METHODS

Original articles reporting the inter-reader reliability of O-RADS US in lesion categorization were identified in the MEDLINE, EMBASE, and Web of Science databases from January 2018 to December 2023. DerSimonian-Laird random-effects models were used to determine the meta-analytic pooled inter-reader reliability of the O-RADS US categorization. Subgroup meta-regression analysis was performed to identify the factors causing study heterogeneity.

RESULTS

Fourteen original articles with 5139 ovarian and adnexal lesions were included. The inter-reader reliability of O-RADS US in lesion categorization ranged from 0.71 to 0.99, with a meta-analytic pooled estimate of 0.83 (95% CI, 0.78-0.88), indicating almost perfect reliability. Substantial study heterogeneity was observed in the inter-reader reliability of the O-RADS US categorization (I2 = 96.9). In subgroup meta-regression analysis, reader experience was the only factor associated with study heterogeneity. Pooled inter-reader reliability of the O-RADS US categorization was higher in studies with all experienced readers (0.86; 95% CI, 0.81-0.91) compared to those with multiple readers including trainees (0.74; 95% CI, 0.70-0.78; P = 0.009). The inter-reader reliability of US descriptors ranged from 0.39 to 0.97, with ascites and peritoneal nodules showing almost perfect reliability (0.79- 0.97).

CONCLUSION

The O-RADS US risk stratification system demonstrated almost perfect inter-reader reliability in lesion categorization. Our results highlight the importance of targeted training and descriptor simplification to improve inter-reader reliability and clinical adoption.

LI-RADS US Surveillance Version 2024 for Surveillance of Hepatocellular Carcinoma: An Update to the American College of Radiology US LI-RADS

In 2017, the American College of Radiology introduced the US Liver Imaging Reporting and Data System (LI-RADS) as a framework for US surveillance of patients at risk for developing hepatocellular carcinoma. This has aided in the standardization of technique, clinical reporting, patient management, data collection, and research. Emerging evidence has helped inform changes to the algorithm, now released as LI-RADS US Surveillance version 2024. The updated algorithm, the rationale for changes, and its alignment with the 2023 American Association for the Study of Liver Diseases Practice Guidance are presented.

Imaging of Cirrhosis and Hepatocellular Carcinoma: Current Evidence

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Early detection of HCC is a key factor in enabling curative therapies and improving overall survival. Worldwide, several guidelines are available for surveillance of at-risk populations and diagnosis of HCC. This article provides a current comprehensive update on screening and diagnosis of HCC.

Role of Imaging in Screening for Hepatocellular Carcinoma

Primary liver cancer is among the most common cancers globally. It is the sixth-most common malignancy encountered and the third-most common cause of cancer-related death. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy, accounting for about 90% of primary liver cancers. The majority of HCCs occur in patients with underlying cirrhosis, which results from chronic liver diseases such as fatty liver, hepatitis B and hepatitis C infections, and chronic alcohol use, which are the leading causes. The obesity pandemic has led to an increased prevalence of nonalcoholic fatty liver disease (NAFLD), which leads to nonalcoholic steatohepatitis and could progress to cirrhosis. As HCC is among the most common cancers and occurs in the setting of chronic liver disease in most patients, screening the population at risk could help in early diagnosis and management, leading to improved survival. Screening for HCC is performed using biochemical marker testing such as α-fetoprotein (AFP) and cross-sectional imaging. It is critical to emphasize that HCC could potentially occur in patients without cirrhosis (non-cirrhotic HCC), which can account for almost 20% of all HCCs. The lack of cirrhosis can cause a delay in surveillance, which could potentially lead to diagnosis at a later stage, worsening the prognosis for such patients. In this article, we discuss the diagnosis of cirrhosis in at-risk populations with details on the different modalities available for screening HCC in patients with cirrhosis, emphasizing the role of abdominal ultrasounds, the primary imaging modality in HCC screening.

MRI for hepatocellular carcinoma and the role of abbreviated MRI for surveillance of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) constitutes the majority of liver cancers and significantly impacts global cancer mortality. While ultrasound (US) with or without alpha-fetoprotein is the mainstay for HCC surveillance, its limitations highlight the necessity for more effective surveillance tools. Therefore, this review explores evolving imaging modalities and abbreviated magnetic resonance imaging (MRI) (AMRI) protocols as promising alternatives, addressing challenges in HCC surveillance.

AREAS COVERED

This comprehensive review delves into the evaluation and challenges of HCC surveillance tools, focusing on non-contrast abbreviated MRI (NC-AMRI) and contrast-enhanced abbreviated MRI protocols. It covers the implementation of AMRI for HCC surveillance, patient preferences, adherence, and strategies for optimizing cost-effectiveness. Additionally, the article provides insights into prospects for HCC surveillance by summarizing meta-analyses, prospective studies, and ongoing clinical trials evaluating AMRI protocols.

EXPERT OPINION

The opinions underscore the transformative impact of AMRI on HCC surveillance, especially in overcoming US limitations. Promising results from NC-AMRI protocols indicate its potential for high-risk patient surveillance, though prospective studies in true surveillance settings are essential for validation. Future research should prioritize risk-stratified AMRI protocols and address cost-effectiveness for broader clinical implementation, alongside comparative analyses with US for optimal surveillance strategies.

Prospective Study of Non-Contrast, Abbreviated MRI for Hepatocellular Carcinoma Surveillance in Patients with Suboptimal Hepatic Visualisation on Ultrasound

BACKGROUND

Biannual ultrasound (US) is recommended for hepatocellular carcinoma (HCC) surveillance in patients with cirrhosis. However, US has limited sensitivity for early-stage HCC, particularly in overweight cohorts, where hepatic visualisation is often inadequate. Currently there are no robust imaging surveillance strategies in patients with inadequate US visualisation. We investigated the ability of non-contrast, abbreviated magnetic resonance imaging (aMRI) to adequately visualise the liver for HCC surveillance in patients with previously inadequate US.

METHODS

Patients undergoing US surveillance, where liver visualisation was inadequate (LI-RADS VIS-B and VIS-C), were prospectively recruited. Patients underwent non-contrast T2-weighted and diffusion-weighted aMRI. The images were reviewed and reported by an expert liver radiologist. Three independent, blinded radiologists assessed the aMRI visualisation quality using a binary score assessing five parameters (parenchymal definition, vascular definition, coverage of the liver, uniformity of liver appearance and signal-to-noise ratio).

RESULTS

Thirty patients completed the aMRI protocol. The majority (90%) had underlying cirrhosis and were overweight (93.3%), with 50% obese and 20% severely obese. A total of 93.3% of the aMRI scans were of satisfactory quality. Six patients (20%) had hepatic abnormalities detected with aMRI that were not seen on their US: one HCC, one haemangioma and three clinically insignificant lesions. For the aMRI visualisation quality assessment, the coverage of the liver, vascular definition and parenchymal definition were consistently rated to be of sufficient quality by all three radiologists.

CONCLUSIONS

Non-contrast aMRI provided good visualisation of the liver and detection of abnormalities in patients with inadequate US. aMRI should be further explored in a larger, prospective study as an alternative surveillance strategy in patients with inadequate US.

The Future Role of Abdominal US in Hepatocellular Carcinoma Surveillance

Abdominal US is currently the best-validated surveillance strategy for hepatocellular carcinoma (HCC) in at-risk patients. It is the only modality shown to have completed all five phases of validation and can achieve high sensitivity and specificity for HCC detection, especially when conducted by expert sonographers in high-volume centers. However, US also has limitations, including operator dependency and varying sensitivity in clinical practice. Further, the sensitivity of US for early-stage HCC detection is lower in patients with obesity or nonviral liver disease, increasingly common populations undergoing surveillance. Imaging-based and blood-based surveillance strategies, including abbreviated MRI and biomarker panels, may overcome some limitations of US-based surveillance. Both strategies have promising test performance in phase II and phase III biomarker studies and are undergoing prospective validation. Considering the variation in HCC risk and test performance between patients, there will likely be a shift away from a one-size-fits-all approach and toward precision screening, in which the "best" test is selected based on individual patient characteristics. In this upcoming era of precision HCC screening among patients with cirrhosis, US will likely continue to have an important, albeit reduced, surveillance role.

Usefulness of Body Position Change during Local Ablation Therapies for the High-Risk Location Hepatocellular Carcinoma

Local ablation therapies are important treatment options for early-stage hepatocellular carcinoma (HCC). Various techniques have been used to perform these therapies efficiently and safely. However, few reports have discussed the usefulness of body position change (BPC). This study aimed to investigate the usefulness of BPC during local ablation therapies in patients with HCC. We evaluated 283 HCC nodules that underwent local ablation therapy. These nodules were categorized into high- or low-risk locations on the basis of their proximity to large vessels, adjacent extrahepatic organs, or poor visibility under ultrasound (US) guidance. The technical success rates, procedure time, and prognosis were evaluated. In this study, 176 (62%) nodules were classified in the high-risk location group. The high-risk location group was treated with techniques such as BPC, artificial pleural fluid, artificial ascites, fusion imaging, and contrast-enhanced US more frequently than the low-risk location group. The technical success rates were 96% and 95% for the high- and low-risk location groups, respectively. Within the high-risk location group, those without BPC had a lower success rate than those with BPC (91% vs. 99%, p = 0.015). Notably, BPC emerged as the sole contributing factor to the technical success rate in the high-risk location group (OR = 10, 95% CI 1.2-86, p = 0.034). In contrast, no differences were found in the procedure time, local tumor progression rates, intrahepatic distant recurrence rates, and overall survival between the groups with and without BPC in the high-risk location group. In conclusion, BPC during local ablation therapy in patients with HCC in high-risk locations was safe and efficient. The body position should be adjusted for HCC in high-risk locations to maintain good US visibility and ensure a safe puncture route in patients undergoing local ablation therapies.

NAFLD and NAFLD-related HCC in Asia: Burden and Surveillance

Non-alcoholic fatty liver disease (NAFLD) is rapidly emerging as a leading etiology of chronic liver disease (CLD) in Asia. The increasing incidence of NAFLD is projected to drive a surge in NAFLD-related hepatocellular carcinoma (HCC). A notable characteristic of NAFLD-HCC is its capacity for development in individuals without cirrhosis in more than a third of patients. Most practice guidelines recommend biannual ultrasound screening for patients with cirrhosis. In cases of severe limitations to ultrasound visualisation, cross-sectional abdominal imaging may be warranted. Improved strategies for HCC risk stratification are required for people with NAFLD but without cirrhosis. In this Review, we discuss the evolving trends of NAFLD and HCC in Asia, and implications for surveillance.

US LI-RADS in surveillance for recurrent hepatocellular carcinoma after curative treatment

OBJECTIVES

To investigate the performance of US LI-RADS in surveillance for recurrent hepatocellular carcinoma (RHCC) after curative treatment.

MATERIALS AND METHODS

This study enrolled 644 patients between January 2018 and August 2018 as a derivation cohort, and 397 patients from September 2018 to December 2018 as a validation cohort. The US surveillance after HCC curative treatment was performed. The US LI-RADS observation categories and visualization scores were analyzed. Four criteria using US LI-RADS or Alpha-fetoprotein (AFP) as the surveillance algorithm were evaluated. The sensitivity, specificity, and negative predictive value (NPV) were calculated.

RESULTS

A total of 212 (32.9%) patients in derivation cohort and 158 (39.8%) patients in validation cohort were detected to have RHCCs. The criterion of US-2/3 or AFP ≥ 20 µg/L had higher sensitivity (derivation, 96.7% vs 92.9% vs 81.1% vs 90.6%; validation, 96.2% vs 90.5% vs 80.4% vs 89.9%) and NPV (derivation, 95.7% vs 93.3% vs 88.0% vs 91.8%; validation, 94.6% vs 89.4% vs 83.6% vs 89.0%), but lower specificity (derivation, 35.9% vs 48.2% vs 67.6% vs 51.9%; validation, 43.5% vs 52.7% vs 66.1% vs 54.0%) than criterion of US-2/3, US-3, and US-3 or AFP ≥ 20 µg/L. Analysis of the visualization score subgroups confirmed that the sensitivity (89.2-97.6% vs 81.0-83.3%) and NPV(88.4-98.0% vs 80.0-83.3%) of score A and score B groups were higher than score C group in criterion of US-2/3 in both two cohorts.

CONCLUSIONS

In the surveillance for RHCC, US LI-RADS with AFP had a high sensitivity and NPV when US-2/3 or AFP ≥ 20 µg/L was considered a criterion.

CLINICAL RELEVANCE STATEMENT

The criterion of US-2/3 or AFP ≥ 20 µg/L improves sensitivity and NPV for RHCC surveillance, which provides a valuable reference for patients in RHCC surveillance after curative treatment.

KEY POINTS

• US LI-RADS with AFP had high sensitivity and NPV in surveillance for RHCC when considering US-2/3 or AFP ≥ 20 µg/L as a criterion. • After US with AFP surveillance, patients with US-2/3 or AFP ≥ 20 µg/L should perform enhanced imaging for confirmative diagnosis. Patients with US-1 or AFP < 20 µg/L continue to repeat US with AFP surveillance. • Patients with risk factors for poor visualization scores limited the sensitivity of US surveillance in RHCC.

Utility of fusion imaging for the evaluation of ultrasound quality in hepatocellular carcinoma surveillance

PURPOSE

This study evaluated the quality of surveillance ultrasound (US) for hepatocellular carcinoma (HCC) utilizing fusion imaging.

METHODS

This research involved a secondary analysis of a prospectively recruited cohort. Under institutional review board approval, participants referred for surveillance US who had undergone liver computed tomography (CT) or magnetic resonance imaging (MRI) within the past year were screened between August 2022 and January 2023. After patient consent was obtained, the US visualization score in the Liver Imaging Reporting and Data System was assessed with fusion imaging at the time of examination. This score was compared to that of conventional US using the extended McNemar test. Multivariable logistic regression analysis was used to identify factors independently associated with a US visualization score of B or C. Factors limiting visualization of focal lesions were recorded during fusion imaging.

RESULTS

Among the 105 participants (mean age, 59±11 years; 66 men), US visualization scores of B and C were assigned to 57 (54.3%) and 17 (16.2%) participants, respectively, by conventional US and 54 (51.4%) and 32 (30.5%) participants, respectively, by fusion imaging. The score distribution differed significantly between methods (P=0.010). Male sex was independently associated with US visualization scores of B or C (adjusted odds ratio, 3.73 [95% confidence interval, 1.30 to 10.76]; P=0.015). The most common reason (64.5%) for lesion nondetection was a limited sonic window.

CONCLUSION

Conventional US may underestimate the limitations of the sonic window relative to real-time fusion imaging with pre-acquired CT or MRI in the surveillance of HCC.

Comparison of Radiologists and Deep Learning for US Grading of Hepatic Steatosis

Background Screening for nonalcoholic fatty liver disease (NAFLD) is suboptimal due to the subjective interpretation of US images. Purpose To evaluate the agreement and diagnostic performance of radiologists and a deep learning model in grading hepatic steatosis in NAFLD at US, with biopsy as the reference standard. Materials and Methods This retrospective study included patients with NAFLD and control patients without hepatic steatosis who underwent abdominal US and contemporaneous liver biopsy from September 2010 to October 2019. Six readers visually graded steatosis on US images twice, 2 weeks apart. Reader agreement was assessed with use of κ statistics. Three deep learning techniques applied to B-mode US images were used to classify dichotomized steatosis grades. Classification performance of human radiologists and the deep learning model for dichotomized steatosis grades (S0, S1, S2, and S3) was assessed with area under the receiver operating characteristic curve (AUC) on a separate test set. Results The study included 199 patients (mean age, 53 years ± 13 [SD]; 101 men). On the test set (n = 52), radiologists had fair interreader agreement (0.34 [95% CI: 0.31, 0.37]) for classifying steatosis grades S0 versus S1 or higher, while AUCs were between 0.49 and 0.84 for radiologists and 0.85 (95% CI: 0.83, 0.87) for the deep learning model. For S0 or S1 versus S2 or S3, radiologists had fair interreader agreement (0.30 [95% CI: 0.27, 0.33]), while AUCs were between 0.57 and 0.76 for radiologists and 0.73 (95% CI: 0.71, 0.75) for the deep learning model. For S2 or lower versus S3, radiologists had fair interreader agreement (0.37 [95% CI: 0.33, 0.40]), while AUCs were between 0.52 and 0.81 for radiologists and 0.67 (95% CI: 0.64, 0.69) for the deep learning model. Conclusion Deep learning approaches applied to B-mode US images provided comparable performance with human readers for detection and grading of hepatic steatosis. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Tuthill in this issue.

The combination of non-contrast abbreviated MRI and alpha foetoprotein has high performance for hepatocellular carcinoma screening

OBJECTIVES

This study aimed to compare two abbreviated MRI (AMRI) protocols to complete MRI for HCC detection: non-contrast (NC)-AMRI without/with alpha foetoprotein (AFP) and dynamic contrast-enhanced (Dyn)-AMRI.

METHODS

This retrospective single-center study included 351 patients (M/F: 264/87, mean age: 57y) with chronic liver disease, who underwent MRI for HCC surveillance between 2014 and 2020. Two reconstructed AMRI sets were obtained based on complete MRI: NC-AMRI (T2-weighted imaging (WI) + diffusion-WI) and Dyn-AMRI (T2-WI + dynamic T1-WI) and were assessed by 2 radiologists who reported all suspicious lesions, using LI-RADS/adapted LI-RADS classification. The reference standard was based on all available patient data. Inter-reader agreement was assessed and MRI diagnostic performance was compared to the reference standard.

RESULTS

The reference standard demonstrated 83/351 HCC-positive patients (prevalence: 23.6%, median size: 22 mm, and positive MRIs: 83/631). Inter-reader agreement was substantial for all sets. Sensitivities of Dyn-AMRI and complete MRI (both 92.8%) were similar, higher than NC-AMRI (72.3%, p < 0.001). Specificities were not different between sets. NC-AMRI + AFP (92.8%) had similar sensitivity to Dyn-AMRI and complete MRI. In patients with small size HCCs (≤ 2 cm), sensitivities of Dyn-AMRI (85.3%) and complete MRI (88.2%) remained similar (p = 0.564), also outperforming NC-AMRI (52.9%, p < 0.05). NC-AMRI + AFP had similar sensitivity (88.2%) to Dyn-AMRI and complete MRI (p = 0.706 and p = 1, respectively).

CONCLUSIONS

Dyn-AMRI has similar diagnostic performance to complete MRI for HCC detection, while both outperform NC-AMRI, especially for small size HCCs. NC-AMRI + AFP demonstrates similar sensitivity to Dyn-AMRI and complete MRI.

CLINICAL RELEVANCE STATEMENT

Due to the low sensitivity of ultrasound for hepatocellular screening, new screening methods are needed. Abbreviated MRI (AMRI) is a candidate, especially non-contrast AMRI with serum alpha foetoprotein as the acquisition time is low, without the need for contrast medium injection.

KEY POINTS

• Dynamic contrast-enhanced abbreviated MRI using extracellular gadolinium-based contrast agent and complete MRI have similar diagnostic performance for hepatocellular carcinoma detection in an at-risk population. • Non-contrast abbreviated MRI with alpha foetoprotein has similar diagnostic performance to dynamic contrast-enhanced abbreviated MRI and complete MRI, including when considering small size hepatocellular carcinoma  ≤ 2 cm. • Non-contrast abbreviated MRI and dynamic contrast-enhanced abbreviated MRI can be performed in 7 and 10 min, excluding patient setup time.

Exploring Opportunities to Enhance the Screening and Surveillance of Hepatocellular Carcinoma in Non-Alcoholic Fatty Liver Disease (NAFLD) through Risk Stratification Algorithms Incorporating Ultrasound Elastography

Non-alcoholic fatty liver disease (NAFLD), with its progressive form, non-alcoholic steatohepatitis (NASH), has emerged as a significant public health concern, affecting over 30% of the global population. Hepatocellular carcinoma (HCC), a complication associated with both cirrhotic and non-cirrhotic NAFLD, has shown a significant increase in incidence. A substantial proportion of NAFLD-related HCC occurs in non-cirrhotic livers, highlighting the need for improved risk stratification and surveillance strategies. This comprehensive review explores the potential role of liver ultrasound elastography as a risk assessment tool for HCC development in NAFLD and highlights the importance of effective screening tools for early, cost-effective detection and improved management of NAFLD-related HCC. The integration of non-invasive tools and algorithms into risk stratification strategies could have the capacity to enhance NAFLD-related HCC screening and surveillance effectiveness. Alongside exploring the potential advancement of non-invasive tools and algorithms for effectively stratifying HCC risk in NAFLD, we offer essential perspectives that could enable readers to improve the personalized assessment of NAFLD-related HCC risk through a more methodical screening approach.

Taking PI-QUAL beyond the prostate: Towards a standardized radiological image quality score (RI-QUAL)

PURPOSE

To compare the interreader agreement of a novel quality score, called the Radiological Image Quality Score (RI-QUAL), to a slighly modified version of the existing Prostate Imaging Quality (mPI-QUAL) score for magnetic resonance imaging (MRI) of the prostate.

METHODS

A total of 43 consecutive scans were evaluated by two subspecialized radiologists who assigned scores using both the RI-QUAL and mPI-QUAL methods. The interreader agreement was analyzed using three statistical methods: concordance correlation coefficient (CCC), intraclass correlation coefficient (ICC), and Cohen's kappa. Time needed to arrive at a quality judgment was measured and compared using the Wilcoxon signed rank test.

RESULTS

The interreader agreement for RI-QUAL and mPI-QUAL scores was comparable, as evidenced by the high CCC (0.76 vs. 0.77, p = 0.93), ICC (0.86 vs. 0.87, p = 0.93), and moderate Cohen's kappa (0.61 vs. 0.64, p = 0.85) values. Moreover, RI-QUAL assessment was faster than mPI-QUAL (19 vs. 40 s, p = 0.001).

CONCLUSION

RI-QUAL is a new quality score that has comparable interreader agreement to the mPI-QUAL score, but with the potential to be applied to different MRI protocols and even different modalities. Like PI-QUAL, RI-QUAL may also facilitate communication about quality to referring physicians, as it provides a standardized and easily interpretable score. Further studies are warranted to validate the usefulness of RI-QUAL in larger patient cohorts and for other imaging modalities.

The feasibility of early response evaluation using superb microvascular imaging one day after transcatheter arterial chemoembolization for hepatocellular carcinoma

PURPOSE

The purpose of this study was to determine the feasibility of early Superb microvascular imaging (SMI) for prediction of the effect of HCC treatment after transcatheter arterial chemoembolization (TACE).

MATERIALS AND METHODS

A total of 96 HCCs (70 patients) treated with TACE between September 2021 and May 2022 were included in this study. SMI, Color Doppler imaging (CDI), and Power Doppler imaging (PDI) were performed the day after TACE for evaluation of intratumoral vascularity of the lesion using an Aplio500 ultrasound scanner (Toshiba Medical Systems, Corporation, Tochigi, Japan). Grading of the vascular presence was performed using a five-point scale. A dynamic CT image taken after 29-42 days was used for comparison of sensitivity, specificity, and accuracy for detection of tumor vascularity between SMI, CDI, and PDI. Univariate and multivariate analysis were performed for assessment of factors affecting intratumoral vascularity.

RESULTS

Fifty-eight lesions (60%) showed complete remission (CR) and 38 lesions (40%) showed partial response (PR) or no response at 29-42 days on Multi-detector Computed Tomography (MDCT) after TACE. SMI showed sensitivity of 86.84% for detection of intratumoral flow, which was significantly higher compared with that of CDI (10.53%, p < 0.001) and PDI (36.84%, p < 0.001). The results of multivariate analysis indicated that tumor size was a significant factor in detection of blood flow using the SMI technique.

CONCLUSION

Early SMI may be utilized as an adjunctive diagnostic test for evaluation of treated lesions after TACE, particularly when the location of the tumor is in an area of the liver where a suitable sonic window can be identified.

Review article: Available modalities for screening and imaging diagnosis of hepatocellular carcinoma-Current gaps and challenges

BACKGROUND

Hepatocellular carcinoma (HCC) incidence and mortality continue to rise worldwide. Society guidelines recommend HCC screening for patients with chronic hepatitis B (CHB) or cirrhosis. Unfortunately, HCC screening rates remain relatively low, and the performance characteristics of current screening modalities are suboptimal.

AIM

The aim of the study was to discuss the current state of HCC screening and imaging diagnosis utilising standard and emerging imaging modalities in addition to outlining areas of need and ongoing study.

METHODS

A review of the field was performed combining literature searches and expert opinion.

RESULTS

The development of the Liver Imaging Reporting and Data System (LI-RADS version 2018) algorithms have advanced and standardised the imaging diagnosis of HCC. While guidelines recommend US for HCC screening, the sensitivity of ultrasound is highly variable for the detection of early-stage HCC with sensitivity reports ranging from 40% to 80%. Biomarker-based scores such as GALAD and alternative imaging modalities such as abbreviated MRI are promising tools to improve HCC early detection. Patients with non-alcoholic fatty liver disease (NAFLD) and patients hepatitis C (HCV) who have achieved sustained virologic response (SVR) can present a clinical dilemma regarding the need for HCC screening. Biomarkers and elastography can aid in identification of individuals at high risk for HCC in these populations.

CONCLUSIONS

The LI-RADS system has standardised the imaging interpretation and diagnosis of HCC. Work remains regarding screening in special populations and optimization of screening modalities.

Hepatocellular carcinoma: State of the art diagnostic imaging

Primary liver cancer is the fourth most common malignancy worldwide, with hepatocellular carcinoma (HCC) comprising up to 90% of cases. Imaging is a staple for surveillance and diagnostic criteria for HCC in current guidelines. Because early diagnosis can impact treatment approaches, utilizing new imaging methods and protocols to aid in differentiation and tumor grading provides a unique opportunity to drastically impact patient prognosis. Within this review manuscript, we provide an overview of imaging modalities used to screen and evaluate HCC. We also briefly discuss emerging uses of new imaging techniques that offer the potential for improving current paradigms for HCC characterization, management, and treatment monitoring.

Risk Assessment and Cholangiocarcinoma: Diagnostic Management and Artificial Intelligence

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver tumor, with a median survival of only 13 months. Surgical resection remains the only curative therapy; however, at first detection, only one-third of patients are at an early enough stage for this approach to be effective, thus rendering early diagnosis as an efficient approach to improving survival. Therefore, the identification of higher-risk patients, whose risk is correlated with genetic and pre-cancerous conditions, and the employment of non-invasive-screening modalities would be appropriate. For several at-risk patients, such as those suffering from primary sclerosing cholangitis or fibropolycystic liver disease, the use of periodic (6-12 months) imaging of the liver by ultrasound (US), magnetic Resonance Imaging (MRI)/cholangiopancreatography (MRCP), or computed tomography (CT) in association with serum CA19-9 measurement has been proposed. For liver cirrhosis patients, it has been proposed that at-risk iCCA patients are monitored in a similar fashion to at-risk HCC patients. The possibility of using Artificial Intelligence models to evaluate higher-risk patients could favor the diagnosis of these entities, although more data are needed to support the practical utility of these applications in the field of screening. For these reasons, it would be appropriate to develop screening programs in the research protocols setting. In fact, the success of these programs reauires patient compliance and multidisciplinary cooperation.

Positive predictive value of LI-RADS US-3 observations: multivariable analysis of clinical and imaging features

PURPOSE

To determine how clinical and imaging features affect the positive predictive values (PPV) of US-3 observations.

METHODS

In this retrospective study, 10,546 adult patients who were high risk for hepatocellular carcinoma (HCC) from 2017 to 2021 underwent ultrasound screening/surveillance. Of these, 225 adult patients (100 women, 125 men)  with an US-3 observation underwent diagnostic characterization with multiphasic CT (93; 41%), MRI (130; 58%), or contrast-enhanced ultrasound (2; 1%). US-3 observations included focal observations ≥ 10 mm in 216 patients and new venous thrombi in 9 patients. PPV with 95% confidence intervals were calculated using diagnostic characterization as the reference standard. Multivariable analysis of clinical and imaging features was performed to determine the strongest associations with cancer.

RESULTS

Overall PPV for an US-3 observation was 33% (27-39%) for at least intermediate probability of cancer (≥ LR-3) and 15% (10-20%) for at least probable cancer (≥ LR-4). At multivariable analysis, cirrhosis had the strongest effect size for at least probable cancer (p < 0.001; odds ratio OR 20.4), followed by observation size (p < 0.001; OR 2.65) and age (p = 0.004; OR 1.05). Alpha-fetoprotein, visualization score, and observation echogenicity were not statistically significant associations. Modality (MRI versus CT) did not affect PPV. Due to the large effect of cirrhosis, PPV was then stratified by the presence (n = 116; 52%) or absence (n = 109; 48%) of cirrhosis. For at least probable cancer (≥ LR-4), PPV increased from 4% (0-7%; non-cirrhotic) to 26% (18-34%; p < 0.001; cirrhosis).

CONCLUSION

Cirrhosis most strongly affects PPV of US-3 observations for at least probable cancer at diagnostic characterization among high-risk patients, increasing to 1 in 4 among cirrhotic patients from 1 in 25 among non-cirrhotic patients.

Prevalence of extra-hepatic incidental findings on ultrasound screening for hepatocellular carcinoma

PURPOSE

Abdominal ultrasound is a cost-effective method for screening for hepatocellular carcinoma (HCC) in high-risk individuals. Currently, at many institutions the protocol for obtaining HCC screening ultrasounds includes a traditional examination of the right upper quadrant, including the pancreas and right kidney. There is no consensus on the role of imaging of extra-hepatic structures and there are limited data describing the frequency and clinical significance of incidental findings discovered during HCC screening. The purpose of this retrospective study is to assess the prevalence and significance of extra-hepatic incidental findings during HCC screening ultrasounds.

METHODS

A single-center retrospective review of all right upper quadrant HCC screening ultrasounds identified 432 HCC screening ultrasounds performed on 294 adults over a 2.5-year period. Findings in all organs evaluated were recorded. Any incidental finding was classified as minor, moderate, or major clinical significance.

RESULTS

At least one extra-hepatic finding was documented in 57.4% of examinations. The most common extra-hepatic findings occurred in the gallbladder (40.3%), most commonly gallstones (25.4%). Four moderate clinically significant incidental findings were recorded (0.9%). Only one of these incidental findings required specific imaging follow up (0.2%). No major clinical significance incidental findings were identified.

CONCLUSIONS

Potentially clinically significant incidental findings during ultrasound HCC screenings are rare. Incidental findings identified on HCC screening did not result in significant additional follow-up imaging or interventions.

Morphometric analysis of tumor microvessels for detection of hepatocellular carcinoma using contrast-free ultrasound imaging: A feasibility study

Introduction

A contrast-free ultrasound microvasculature imaging technique was evaluated in this study to determine whether extracting morphological features of the vascular networks in hepatic lesions can be beneficial in differentiating benign and malignant tumors (hepatocellular carcinoma (HCC) in particular).

Methods

A total of 29 lesions from 22 patients were included in this work. A post-processing algorithm consisting of clutter filtering, denoising, and vessel enhancement steps was implemented on ultrasound data to visualize microvessel structures. These structures were then further characterized and quantified through additional image processing. A total of nine morphological metrics were examined to compare different groups of lesions. A two-sided Wilcoxon rank sum test was used for statistical analysis.

Results

In the malignant versus benign comparison, six of the metrics manifested statistical significance. Comparing only HCC cases with the benign, only three of the metrics were significantly different. No statistically significant distinction was observed between different malignancies (HCC versus cholangiocarcinoma and metastatic adenocarcinoma) for any of the metrics.

Discussion

Obtained results suggest that designing predictive models based on such morphological characteristics on a larger sample size may prove helpful in differentiating benign from malignant liver masses.

Outcomes of LI-RADS US-2 Subthreshold Observations Detected on Surveillance Ultrasound

BACKGROUND. Ultrasound LI-RADS version 2017 recommends that patients with US-2 subthreshold observations undergo repeat surveillance ultrasound in 3-6 months and return to routine surveillance if the observation shows no growth for 2 years. However, outcomes of US-2 observations are unknown. OBJECTIVE. The purpose of this article was to determine imaging outcomes of US-2 observations detected on surveillance ultrasound examinations. METHODS. This retrospective study included 175 patients (median age, 59 years; 70 women, 105 men) at high risk for hepatocellular carcinoma (HCC) with US-2 observations (i.e., subcentimeter observations) on surveillance ultrasound. Observations were classified on follow-up ultrasound performed 2 or more years later as showing no correlate, stable (if remaining subcentimeter), or progressed (if measuring ≥ 10 mm, meeting US-3 criteria). Observations were classified on follow-up multiphasic CT or MRI (stratified as < 2-year vs ≥ 2-year follow-up) as showing no correlate or, if showing a correlate, using CT/MRI LI-RADS version 2018. RESULTS. A total of 111 patients had follow-up ultrasound after 2 or more years and 106 had follow-up CT or MRI (79 before 2 years, 27 after 2 years). On the basis of final follow-up examinations, 173 of 175 observations were stable on follow-up ultrasound 2 or more years later (n = 68); showed no correlate on follow-up ultrasound, CT, or MRI (n = 88); or were classified as LR-1 or LR-2 on CT or MRI (n = 17). The remaining 2 of 175 observations were LR-3 on CT or MRI. No observations progressed to US-3 on follow-up ultrasound or were classified as LR-4 or greater on CT or MRI. A correlate was observed in 25 of the 106 follow-up CT or MRI examinations (LR-1 or LR-2 in 23; LR-3 in two). Eight patients developed HCC at a median of 2.0 years after initial US-2 observation detection; all HCCs were in separate locations from the baseline observations and were preceded by a surveillance ultrasound that could not reidentify the baseline observation. In three patients who underwent liver transplant, the explant showed no dysplastic nodule or HCC. CONCLUSION. US-2 subthreshold observations are unlikely to progress or become HCC and commonly have no correlate on follow-up imaging. CLINICAL IMPACT. Because of the low progression rate of US-2 subthreshold observations, it is unclear if an extended period of intensive surveillance, as recommended by multiple professional societies, is warranted.

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

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

Interobserver Agreement Between Primary Sonographers and Secondary Overreaders for Screening and Surveillance Liver Ultrasounds Using Ultrasound Liver Imaging Reporting and Data System

ABSTRACT

The authors aim to identify if primary sonographers and secondary reviewers, both radiologists and sonographers, are likely to assign the same Ultrasound Liver Imaging Reporting and Data System (US LI-RADS) scores for liver surveillance ultrasounds. Institutional review board approval was obtained. Sonographers were familiarized with US LI-RADS via radiologist-led lectures. Three sonographers prospectively scored 170 screening examinations using US LI-RADS recommendations. Scans were retrospectively rescored by a fourth sonographer and a radiologist, both of whom were blinded to the original scores. Results were analyzed with weighted and nonweighted Cohen kappa statistical analysis methods. There was near-perfect agreement between primary and secondary sonographers and primary sonographer and radiologist (kappa of 0.87 and 0.92, respectively) for US LI-RADS category (cat) scores. However, only substantial and moderate agreements were noted for visualization (vis) scores between primary and secondary sonographers and primary sonographer and radiologist (weighted kappa of 0.73 and 0.48, respectively). There was vis score disagreement between the primary sonographer and radiologist in 60 (35.3%) cases. In 35 (20%) cases, the radiologist assigned a lower/more conservative vis score. There was vis score disagreement between the primary and secondary reviewing sonographers in 30 (17.6%) cases. In 12 (7%) cases, the secondary sonographer assigned a more conservative vis score. Although a good degree of concordance was noted between the groups, radiologists will need to generate their own US LI-RADS scoring to accurately reflect their impression and appropriately steer management.

Associations of Ultrasound LI-RADS Visualization Score With Examination, Sonographer, and Radiologist Factors: Retrospective Assessment in Over 10,000 Examinations

BACKGROUND. When performing ultrasound (US) for hepatocellular carcinoma (HCC) screening, numerous factors may impair hepatic visualization, potentially lowering sensitivity. US LI-RADS includes a visualization score as a technical adequacy measure. OBJECTIVE. The purpose of this article is to identify associations between examination, sonographer, and radiologist factors and the visualization score in liver US HCC screening. METHODS. This retrospective study included 6598 patients (3979 men, 2619 women; mean age, 58 years) at risk for HCC who underwent a total of 10,589 liver US examinations performed by 91 sonographers and interpreted by 50 radiologists. Visualization scores (A, no or minimal limitations; B, moderate limitations; C, severe limitations) were extracted from clinical reports. Patient location (emergency department [ED], in-patient, outpatient), sonographer and radiologist liver US volumes during the study period (< 50, 50-500, > 500 examinations), and radiologist practice pattern (US, abdominal, community, interventional) were recorded. Associations with visualization scores were explored. RESULTS. Frequencies of visualization scores were 71.5%, 24.2%, and 4.2% for A, B, and C, respectively. Scores varied significantly (p < .001) between examinations performed in ED patients (49.8%, 40.1%, and 10.2%), inpatients (58.8%, 33.9%, and 7.3%), and outpatients (76.7%, 20.3%, and 2.9%). Scores also varied significantly (p < .001) by sonographer volume (< 50 examinations: 58.4%, 33.7%, and 7.9%; > 500 examinations: 72.9%, 22.5%, and 4.6%); reader volume (< 50 examinations: 62.9%, 29.9%, and 7.1%; > 500 examinations: 67.3%, 28.0%, and 4.7%); and reader practice pattern (US: 74.5%, 21.3%, and 4.3%; abdominal: 67.0%, 28.1%, and 4.8%; community: 75.2%, 21.9%, and 2.9%; interventional: 68.5%, 24.1%, and 7.4%). In multivariable analysis, independent predictors of score C were patient location (ED/inpatient: odds ratio [OR], 2.62; p < .001) and sonographer volume (< 50: OR, 1.55; p = .01). Among sonographers performing 50 or more examinations, the percentage of outpatient examinations with score C ranged from 0.8% to 5.4%; 9/33 were above the upper 95% CI of 3.2%. CONCLUSION. The US LI-RADS visualization score may identify factors affecting quality of HCC screening examinations and identify outlier sonographers in terms of poor examination quality. The approach also highlights potential systematic biases among radiologists in their quality assessment process. CLINICAL IMPACT. These findings may be applied to guide targeted quality improvement efforts and establish best practices and performance standards for screening programs.

Multicenter Study of ACR Ultrasound LI-RADS Visualization Scores on Serial Examinations: Implications for Changes in Surveillance Strategies

Background: American College of Radiology Ultrasound LI-RADS includes the visualization score as a subjective measure of examination quality and expected level of sensitivity. Whether a single suboptimal visualization score warrants change in surveillance strategy is unknown. Objective: To determine the relative stability of visualization scores on serial surveillance ultrasound examinations in patients at risk for HCC. Methods: This retrospective study included patients at risk for HCC who underwent at least two HCC surveillance ultrasound examinations at one of three institutions between January 2017 and November 2020. Frequencies of score remaining unchanged after variable numbers of preceding examinations with the given score were determined. A mixed-effects logistic model was fitted to identify factors associated with a repeat score C (severe limitations) versus change to score A (no or minimal limitations) or score B (moderate limitations). Results: A total of 3169 patients underwent at least 2 ultrasound examinations, yielding a total of 9602 examinations. A total of 8030 (83.6%) examinations had score A, 1378 (14.4%) score B, and 194 (2.0%) score C. Frequency of score A was 88%, 91%, and 93% after 1, 2 and 3 consecutive prior examinations with score A. Frequency of score B was 45%, 48%, and 55% after 1, 2, and 3 consecutive prior examinations with score B. Frequency of score C was 42%, 67%, and 80% after 1, 2, and 3 consecutive prior examinations with score C. Among 109 examinations with score C in 91 patients with an available follow-up examination, no factor (including age, sex, severe steatosis, advanced cirrhosis, ascites, body mass index, and change in ultrasound machine, sonographer, or radiologist) was significantly associated with repeat score C (all p>.05). Although not statistically significant, presence of severe steatosis and advanced cirrhosis had the highest odds ratios (2.88 and 2.38, respectively) for repeat score C in multivariable analysis. Conclusion: Only 42% of patients with visualization score C on surveillances examination have score C on follow-up examination. Clinical Impact: The findings may inform decisions for alternative surveillance strategies in patients with visualization score C on ultrasound. This decision should consider the number of previous examinations with score C.

Association between ultrasound quality and test performance for HCC surveillance in patients with cirrhosis: a retrospective cohort study

BACKGROUND

Ultrasound visualisation is limited in approximately 20% of patients with cirrhosis undergoing hepatocellular carcinoma (HCC) surveillance; however, it is unknown if impaired visualisation directly impacts test performance. We aimed to evaluate the association between ultrasound visualisation and surveillance test performance.

METHODS

We performed a retrospective cohort study among patients with cirrhosis, with or without HCC, who underwent ultrasound-based surveillance at two large health systems between July 2016 and July 2019. Ultrasound visualisation assessment was recorded by interpreting radiologists using the ultrasound LI-RADS Visualisation score. We performed logistic regression analyses to evaluate the association between ultrasound visualisation and diagnostic test performance. We assessed sensitivity for HCC detection among ultrasounds performed in the year prior to HCC diagnoses and specificity using ultrasounds in those without HCC.

RESULTS

Among 186 patients with HCC, severely limited visualisation (Vis Score C) on ultrasound prior to HCC diagnosis was associated with increased odds of false-negative results, that is lower sensitivity (OR 7.94, 95% CI 1.23-51.16) in multivariable analysis. Ultrasound sensitivity with visualisation scores A or B exceeded 75%, compared to only 27.3% with visualisation score C. Among 2052 cirrhosis patients without HCC, moderate visualisation limitations (Vis score B) were associated with increased odds of false-positive results (OR 1.60, 1.13-2.27), although specificity exceeded 95% across all visualisation scores.

CONCLUSIONS

Impaired ultrasound visualisation is associated with worse surveillance test performance. Alternative blood-based biomarkers and imaging strategies are needed for patients at risk for ultrasound-based surveillance failure.

Rational HCC screening approaches for patients with NAFLD

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of developing hepatocellular carcinoma (HCC), especially among those who have cirrhosis or advanced fibrosis, but 20-30% of cases of NAFLD-related HCC occur in the absence of advanced fibrosis. The prevalence of NAFLD-related HCC is increasing in most countries worldwide. There are few direct data to support or refute the efficacy or effectiveness of HCC surveillance in NAFLD or to guide its application. We use evidence on surveillance in other conditions and studies on the clinical course of patients with NAFLD to arrive at recommendations for rational approaches to HCC surveillance in this growing cohort of patients. We also outline gaps in research and practice, including opportunities to advance the field.

Feature Fusion for Diagnosis of Atypical Hepatocellular Carcinoma in Contrast- Enhanced Ultrasound

Contrast-enhanced ultrasound (CEUS) is generally employed for focal liver lesions (FLLs) diagnosis. Among the FLLs, atypical hepatocellular carcinoma (HCC) is difficult to distinguish from focal nodular hyperplasia (FNH) in CEUS video. For this reason, we propose and evaluate a feature fusion method to resolve this problem. The proposed algorithm extracts a set of hand-crafted features and the deep features from the CEUS cine clip data. The hand-crafted features include the spatial-temporal feature based on a novel descriptor called Velocity-Similarity and Dissimilarity Matching Local Binary Pattern (V-SDMLBP), and the deep features from a 3-D convolution neural network (3D-CNN). Then the two types of features are fused. Finally, a classifier is employed to diagnose HCC or FNH. Several classifiers have achieved excellent performance, which demonstrates the superiority of the fused features. In addition, compared with general CNNs, the proposed fused features have better interpretability.

Ultrasound Liver Imaging Reporting and Data System (US LI-RADS) Visualization Score: a reliability analysis on inter-reader agreement

BACKGROUND & AIM

The American College of Radiology Ultrasound Liver Imaging Reporting and Data System (ACR US LI-RADS) Visualization Score conveys the expected level of sensitivity of screening and surveillance ultrasound exams in patients at risk for hepatocellular carcinoma (HCC). We sought to determine inter-reader agreement of the Visualization Score which is currently unknown.

METHODS

Consecutive 6998 ultrasound HCC screening and surveillance studies in 3115 patients from 2017 to 2020 were retrospectively retrieved. Of these, 6154 (87.9%) studies were Visualization A (No or minimal limitations), 709 (10.1%) were Visualization B (Moderate limitations), and 135 (1.9%) were Visualization C (Severe limitations). Randomly sampled 90 studies, with 30 studies in each Visualization category, were included for analysis. Nine radiologists (3 senior attendings, 3 junior attendings and 3 body imaging fellows) blinded to the original categorization independently reviewed each study and assigned a Visualization Score. Intraclass correlation coefficient (ICC) was used to quantify inter-reader agreement.

RESULTS

ICC among all 9 radiologists was 0.70 (95% CI 0.63-0.77). ICCs among senior attendings, junior attendings and body imaging fellows were 0.68 (CI 0.58-0.76), 0.72 (CI 0.62-0.80) and 0.76 (CI 0.68-0.83), respectively. Subgroup analysis by liver parenchyma was further performed. ICC was highest in the patient group with normal liver parenchyma (0.69, CI 0.56-0.81), followed by steatosis (0.66, CI 0.54-0.79) and cirrhosis (0.58, CI 0.43-0.73), respectively.

CONCLUSIONS

US LI-RADS Visualization Score is a reliable tool with good inter-reader agreement that can be used to indicate the expected level of sensitivity of a screening and surveillance ultrasound examination for detecting focal liver observations.

HCC Detection on Surveillance US: Comparing Focused Liver Protocol Using US LI-RADS Technical Guidelines to a General Complete Abdominal US Protocol

OBJECTIVE

Focused US examinations of the liver in the routine hepatocellular carcinoma (HCC) screening reduce the time spent on evaluating other structures deemed irrelevant to the clinical setting. It is still unknown, however, if such a strategy may additionally improve the frequency of nodules detection. We aimed to assess the impact of an HCC surveillance program in high-risk patients by means of targeted liver US following LI-RADS technical guidelines in comparison to a complete upper abdominal scan.

METHODS

In this IRB-approved, single-center, prospective study, patients at high-risk for HCC enrolled from 06/2016 to 09/2019 were randomly assigned to 1 of the 2 institutional protocols: Group A (targeted liver US) or Group B (complete upper abdominal scan). Twenty examiners with similar experience in abdominal US were randomly assigned to perform the examinations exclusively in 1 of the groups (10 in each group). Frequency of hepatic nodules between groups was compared by using Fisher's exact test.

RESULTS

Four hundred and sixty-five patients were enrolled, with no significant differences in both groups regarding sex, age, etiology of liver disease, MELD scores, and alpha-fetoprotein levels. A significantly higher frequency of nodules detection was found in Group A (230 patients; 23 nodules detected; 10% of the sample) in comparison to Group B (235 patients; 3 nodules; 1.3% of the sample) (p <.001). Five patients in Group A and 1 in Group B were positive for HCC after full diagnostic work-up.

CONCLUSION

Adopting an HCC screening program based on targeted liver US improved the detection of hepatic nodules among high-risk individuals.

Ultrasound Liver Imaging Reporting and Data System (US LI-RADS): An Overview with Technical and Practical Applications

The Ultrasound Liver Imaging Reporting and Data System (US LI-RADS), introduced in 2017 by the American College of Radiology, standardizes the technique, interpretation, and reporting of screening and surveillance ultrasounds intended to detect hepatocellular carcinoma in high-risk patients. These include patients with cirrhosis of any cause as well as subsets of patients with chronic hepatitis B viral infection. The US LI-RADS scheme is composed of an ultrasound category and a visualization score: ultrasound categories define the exam as negative, subthreshold, or positive and direct next steps in management; visualization scores denote the expected sensitivity of the exam, based on adequacy of liver visualization with ultrasound. Since its introduction, multiple institutions across the United States have implemented US LI-RADS. This review includes a background of hepatocellular carcinoma and US LI-RADS, definition of screening/surveillance population, recommendations and tips for technique, interpretation, and reporting, and preliminary outcomes analysis.

Current and Emerging Tools for Hepatocellular Carcinoma Surveillance

Hepatocellular carcinoma (HCC) is a leading cause of cancer‐related mortality worldwide. Early detection of HCC enables patients to avail curative therapies that can improve patient survival. Current international guidelines advocate for the enrollment of patients at high risk for HCC, like those with cirrhosis, in surveillance programs that perform ultrasound every 6 months. In recent years, many studies have further characterized the utility of established screening strategies and have introduced new promising tools for HCC surveillance. In this review, we provide an overview of the most promising new imaging modalities and biomarkers for the detection of HCC. We discuss the role of imaging tools like ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) in the early detection of HCC, and describe recent innovations which can potentially enhance their applicability, including contrast enhanced ultrasound, low‐dose CT scans, and abbreviated MRI. Next, we outline the data supporting the use of three circulating biomarkers (i.e., alpha‐fetoprotein [AFP], AFP lens culinaris agglutinin‐reactive fraction, and des‐gamma‐carboxy prothrombin) in HCC surveillance, and expand on multiple emerging liquid biopsy biomarkers, including methylated cell‐free DNA (cfDNA), cfDNA mutations, extracellular vesicles, and circulating tumor cells. These promising new imaging modalities and biomarkers have the potential to improve early detection, and thus improve survival, in patients with HCC.