The interreader agreement and validation of contrast-enhanced ultrasound liver imaging reporting and data system

Machine learning model based on dynamic contrast-enhanced ultrasound assisting LI-RADS diagnosis of HCC: A multicenter diagnostic study

Background

To enhance the accuracy of hepatocellular carcinoma (HCC) diagnosis using contrast-enhanced (CE) US, the American College of Radiology developed the CEUS Liver Imaging Reporting and Data System (LI-RADS). However, the system still exhibits limitations in distinguishing between HCC and non-HCC lesions.

Purpose

To investigate the viability of employing machine learning methods based on quantitative parameters of contrast-enhanced ultrasound for distinguishing HCC within LR-M nodules.

Materials and methods

This retrospective analysis was conducted on pre-treatment CEUS data from liver nodule patients across multiple centers between January 2013 and June 2022. Quantitative analysis was performed using CEUS images, and the machine learning diagnostic models based on quantitative parameters were utilized for the classification diagnosis of LR-M nodules. The performance of the model was assessed using the area under the receiver operating characteristic curve (AUC) and compared with the performance of four radiologists.

Results

The training and internal testing datasets comprised 168 patients (median age, 53 years [IQR, 18 years]), while the external testing datasets from two other centers included 110 patients (median age, 54 years [IQR, 16 years]). In the internal independent test set, the top-performing Random Forest model achieved an AUC of 0.796 (95%CI: 0.729-0.853) for diagnosing HCC. This model exhibited a sensitivity of 0.752 (95%CI: 0.750-0.755) and a specificity of 0.761 (95%CI: 0.758-0.764), outperforming junior radiologists who achieved an AUC of 0.619 (95%CI: 0.543-0.691, p < .01) with sensitivity and specificity of 0.716 (95%CI: 0.713-0.718) and 0.522 (95%CI: 0.519-0.526), respectively.

Conclusion

Significant differences in contrast-enhanced ultrasound quantitative parameters are observed between HCC and non-HCC lesions. Machine learning models leveraging these parameters effectively distinguish HCC categorized as LR-M, offering a valuable adjunct for the accurate classification of liver nodules within the CEUS LI-RADS framework.

Inter-Reader Agreement for Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System Major Features and Final Categorization: A Subanalysis From a Prospective Multicenter Study

OBJECTIVES

Contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) is used to definitively diagnose hepatocellular carcinoma (HCC) in patients at risk. However, the user variability associated with CEUS LI-RADS has not been validated in North American and European patients. This study aims to evaluate the inter-reader agreements of CEUS LI-RADS features for, and final categorization of, HCC in patients at risk.

METHODS

This retrospective multicenter clinical study used the database of a previous prospective multinational study, evaluating the accuracy of CEUS LI-RADS for HCC diagnosis in patients at risk. All cases were first evaluated by a site physician performing/supervising the CEUS examination. Randomly selected cases were re-evaluated by a blinded central reader. Final diagnosis was confirmed with the reference standard, which was a composite of imaging tests and histology. Cohen's kappa test was used to evaluate inter-reader agreement.

RESULTS

This study included 150 liver nodules and 58.0% (87/150) were confirmed as HCC, 4.7% (7/150) non-HCC malignancies, 22.7% (34/150) had no confirmed final diagnosis, and 14.7% (22/150) were nonmalignant. Inter-reader agreements were substantial for CEUS LI-RADS categorization (κ = 0.61; 95% confidence interval [CI]: 0.51-0.71) and major features assessment (ranged κ = 0.64-0.78), LR-5 (κ = 0.65; 95% CI: 0.52-0.77), and LR-M (κ = 0.67; 95% CI: 0.44-0.90), while for LR-1 and LR-2 categorization was almost perfect (κ = 0.85; 95% CI: 0.65-1.00).

CONCLUSION

Our study reported a substantial inter-reader agreement for overall CEUS LI-RADS categorization, especially for LR-5 and LR-M, and major imaging features of HCC, further confirming CEUS LI-RADS as a valuable and reliable tool for diagnosis of HCC.

Correlation between CEUS LI-RADS categorization of HCC < 20 mm and clinic-pathological features

OBJECTIVE

To retrospectively evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) LI-RADS in liver nodules < 20 mm at high risk of hepatocellular carcinoma (HCC) and their correlation with clinic-pathological features.

METHODS

A total of 432 pathologically proved liver nodules < 20 mm were included from January 2019 to June 2022. Each nodule was categorized as LI-RADS grade (LR)-1 to LR-5 through LR-M according to CEUS LI-RADS. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of CEUS LI-RADS were evaluated using pathological reference standard. Correlations between clinic-pathological features and CEUS LI-RADS categorization, together with major CEUS features, were further explored.

RESULTS

With LR-5 to diagnose HCC, the sensitivity, specificity, PPV, NPV, and AUC were 50.3%, 70.0%, 91.2%, 18.5%, and 0.601, respectively. The proportion of LR-5 in primary HCCs was significantly higher than that in recurrent ones (p = 0.014). HCC 10-19 mm showed significantly more frequent arterial phase hyper-enhancement (APHE) and late washout (p < 0.05) and less no-washout (p = 0.003) compared with those in HCC < 10 mm. Well-differentiated HCCs showed more frequent non-APHE and no-washout than moderate- and poor-differentiated HCCs (p < 0.05). Upgrading "APHE without washout" LR-4 nodules 10-19 mm with HCC history and "APHE with late mild washout" LR-4 nodules < 10 mm to LR-5 could improve the diagnostic performance of LR-5. The corresponding sensitivity, specificity, PPV, NPV, and AUC are 60.2%, 70.0%, 92.6%, 22.1%, and 0.651, respectively.

CONCLUSIONS

CEUS LI-RADS is valuable in the diagnosis of HCC < 20 mm and performance can be improved with the combination of clinic-pathological features.

CRITICAL RELEVANCE STATEMENT

CEUS LI-RADS was valuable in the diagnosis of HCC < 20 mm and its diagnostic performance can be improved by combining clinic-pathological features. Further research is needed to define its value in this set of lesions.

KEY POINTS

Contrast-enhanced ultrasound can detect small liver lesions where LI-RADS accuracy is uncertain. Many LI-RADS Grade-4 nodules were upgraded to Grade-5 by combining imaging with clinic-pathological factors. The reclassification of LI-RADS Grade-5 can improve sensitivity without decreasing positive predictive value.

Performance of current versus modified CEUS LI-RADS in the diagnosis of non-hepatocellular carcinoma malignancies

PURPOSE

The high proportion of HCC in CEUS LR-M decreases the sensitivity of LR-5 for the diagnosis of HCC. However, when modifying LR-M criteria to further improve the sensitivity of LR-5, it is also important not to compromise the diagnostic performance (especially sensitivity) of LR-M for non-hepatocellular carcinoma malignancies (non-HCCMs). The purpose of this study was to evaluate the diagnostic performance of CEUS LI-RADS (2017 version) for non-HCCMs and to explore the impact of modified CEUS LI-RADS on the diagnostic performance of LR-M.

METHODS

In this retrospective study, patients with pathologically confirmed non-HCCMs were evaluated. Two radiologists independently interpreted the major CEUS features and categorized the liver lesions. New LR-M criteria were applied: early washout (< 45 s) or marked washout (< 5 min). The sensitivity values of the current and modified CEUS LR-M were assessed and then compared using a paired χ2 test. Cohen's κ was used to compare the inter-reader agreement of the LI-RADS categories.

RESULTS

A total of 131 non-HCCMs were ultimately selected, including 71 intrahepatic cholangiocarcinomas, 26 combined hepatocellular cholangiocarcinomas, 29 metastases, and 5 other non-HCCMs. The numbers of LR-M, LR-5, LR-4, and LR-3 in liver lesions were 111, 18, 1, and 1, respectively. The inter-reader agreement of the LI-RADS categories for non-HCCMs was 0.59. The sensitivity of the current CEUS LR-M in diagnosing non-HCCMs was 84.7%. By adjusting the early washout time to < 45 s, the sensitivity of LR-M was 80.9%. By adjusting the marked washout time within 5 min, the sensitivity of LR-M was 72.5%.

CONCLUSION

CEUS LR-M has high sensitivity in diagnosing non-HCCMs. For LR-M nodules with nonrim arterial phase hyperenhancement and early washout, advancing the time of early washout to < 45 s has a minimal impact on the sensitivity of LR-M in diagnosing non-HCCMs compared to the condition of increasing the marked washout within 5 min.

Differences between CEUS LI-RADS and CECT LI-RADS in the diagnosis of focal liver lesions in patients at risk for HCC

OBJECTIVES

To compare the inter-modality consistency and diagnostic performances of the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) and contrast-enhanced computed tomography (CECT) LI-RADS in patients at risk for hepatocellular carcinoma (HCC), so as to help clinicians to select a more appropriate modality to follow the focal liver lesions (FLLs).

METHODS

This retrospective study included untreated 277 FLLs from 247 patients who underwent both CEUS and CECT within 1 month. The ultrasound contrast medium used was SonoVue. FLL categories were independently assigned by two ultrasound physicians and two radiologists using CEUS LI-RADS v2017 and CECT LI-RADS v2018, respectively. The diagnostic performances of CEUS and CECT LI-RADS were evaluated using sensitivity, specificity, positive predictive value (PPV), and negative predictive value. Cohen's Kappa was employed to evaluate the concordance of the LI-RADS category.

RESULTS

The inter-modality consistency for CEUS and CECT LI-RADS was 0.31 (p < 0.001). HCC was more frequently observed in CECT LR-3 and LR-4 hepatic lesions than in CEUS (7.3% vs. 19.5%, p < 0.001). The specificity and PPV of CEUS and CECT LR-5 for the diagnosis of HCC were 89.5%, 95.0%, and 82.5%, 94.4%, respectively. The sensitivity of CEUS LR-5 + LR-M for the diagnosis of hepatic malignancies was higher than that of CECT (93.7% vs. 82.7%, p < 0.001). The specificity and PPV of CEUS LR-M for the diagnosis of non-HCC malignancies were lower than those of CECT (59.7% vs. 95.5%, p < 0.001; 23.4% vs. 70.3%, p < 0.001).

CONCLUSIONS

The inter-modality consistency between the CEUS and CECT LI-RADS categories is fair. CEUS LI-RADS was more sensitive than CECT LI-RADS in terms of identifying hepatic malignancies, but weaker in terms of separating HCC from non-HCC malignancies.

Contrast-enhanced US with Sulfur Hexafluoride and Perfluorobutane: LI-RADS for Diagnosing Hepatocellular Carcinoma

Background Liver Imaging Reporting and Data System (LI-RADS) was designed for contrast-enhanced US (CEUS) with pure blood pool agents to diagnose hepatocellularfcarcinoma (HCC), such as sulfur hexafluoride (SHF), but Kupffer-cell agents, such as perfluorobutane (PFB), allow additional lesion characterization in the Kupffer phase yet remain unaddressed. Purpose To compare the diagnostic performance of three algorithms for HCC diagnosis: two algorithms based on CEUS LI-RADS version 2017 for both SHF and PFB and a modified algorithm incorporating Kupffer-phase findings for PFB. Materials and Methods This multicenter prospective study enrolled high-risk patients for HCC from June 2021 to December 2021. Each participant underwent same-day SHF-enhanced US followed by PFB-enhanced US. Each liver observation was assigned three LI-RADS categories according to each algorithm: LI-RADS SHF, LI-RADS PFB, and modified PFB. For modified PFB, observations at least 10 mm with nonrim arterial phase hyperenhancement were upgraded LR-4 to LR-5 if there was no washout with a Kupffer defect and were reassigned LR-M to LR-5 if there was early washout with mild Kupffer defect. The reference standard was pathologic confirmation or composite (typical CT or MRI features, or 1-year size stability and/or reduction). Diagnostic metrics of LR-5 for HCC using the three algorithms were calculated and compared using the McNemar test. Results Overall, 375 patients (mean age, 56 years ± 11 [SD]; 318 male patients, 57 female patients) with 424 observations (345 HCCs, 40 non-HCC malignancies, 39 benign lesions) were enrolled. PFB and SHF both using LI-RADS showed no significant difference in sensitivity (60% vs 58%; P = .41) and specificity (96% vs 95%; P > .99). The modified algorithm with PFB had increased sensitivity (80% vs 58%; P < .001) and a nonsignificant decrease in specificity (92% vs 95%; P = .73) compared with LI-RADS SHF. Conclusion Based on CEUS LI-RADS version 2017, both SHF and PFB achieved high specificity and relatively low sensitivity for HCC diagnosis. When incorporating Kupffer-phase findings, PFB had higher sensitivity without loss of specificity. Chinese Clinical Trial Registry no. ChiCTR2100047035 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Kim in this issue.

Intraindividual Comparison of Contrast-Enhanced Ultrasound Using Perfluorobutane With Modified Criteria Versus CT/MRI LI-RADS Version 2018 for Diagnosing HCC in High-Risk Patients

BACKGROUND. Previously proposed modifications to LI-RADS criteria for contrast-enhanced ultrasound (CEUS) performed using perfluorobutane contrast agent yielded increased sensitivity for hepatocellular carcinoma (HCC) without a significant decrease in specificity. OBJECTIVE. The purpose of our study was to compare the diagnostic performance of CEUS with perfluorobutane using modified LI-RADS criteria versus contrast-enhanced CT or MRI using LI-RADS version 2018 (v2018) for characterizing lesions as HCC in high-risk patients. METHODS. This retrospective study included 171 patients (140 men, 31 women; mean age, 54 ± 12 [SD] years) at high-risk for HCC with a pathologically confirmed liver observation evaluated by both CEUS using perfluorobutane and contrast-enhanced CT or MRI between March 2020 and May 2021. A matching algorithm was used to select two patients with HCC for each patient with a non-HCC lesion. Two readers evaluated observations using previously proposed modifications to CEUS LI-RADS version 2017 that classify certain observations as LR-5 rather than as LR-4 or LR-M on the basis of the presence of Kupffer phase defect after perfluorobutane administration; two different readers evaluated observations using CT/MRI LI-RADS v2018. Each reader pair reached consensus. Diagnostic performance was evaluated. RESULTS. A total of 114 patients had HCC, 43 had a non-HCC malignancy, and 14 had a benign lesion. Modified CEUS criteria using perfluorobutane and CT/MRI LI-RADS v2018 showed no significant difference (p > .05) in sensitivity (92.1% vs 89.5%), specificity (87.7% vs 84.2%), or accuracy (90.6% vs 87.7%) of LR-5 for diagnosis of HCC. Of six observations assessed as LR-4 only by CT/MRI LI-RADS v2018, modified CEUS criteria using perfluorobutane assessed one as LR-3 (benign lesion) and five as LR-5 (all HCC). Of seven observations assessed as LR-M only by CT/MRI LI-RADS v2018, modified CEUS criteria using perfluorobutane assessed one as LR-3 (non-HCC malignancy) and six as LR-5 (all HCC). Eight of 12 observations assessed as LR-5 only by CT/MRI LI-RADS v2018 and 11 of 13 observations assessed as LR-5 only by modified CEUS criteria using perfluorobutane were HCC. CONCLUSION. The diagnostic performance of LR-5 for HCC diagnosis was not significantly different between modified CEUS criteria using perfluorobutane and CT/MRI LI-RADS v2018. CLINICAL IMPACT. The findings support the application of modified CEUS criteria using perfluorobutane for diagnosing HCC in high-risk patients.

Contrast-enhanced ultrasound for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease

BACKGROUND

Hepatocellular carcinoma occurs mostly in people with chronic liver disease. Worldwide, it ranks sixth in terms of incidence of cancer, and fourth in terms of cancer-related deaths. Contrast-enhanced ultrasound (CEUS) is used as an add-on test to confirm the presence of focal liver lesions suspected as hepatocellular carcinoma after prior diagnostic tests such as abdominal ultrasound or measurement of alpha-foetoprotein, or both. According to guidelines, a single contrast-enhanced imaging investigation, with either computed tomography (CT) or magnetic resonance imaging (MRI), may show the typical hepatocellular carcinoma hallmarks in people with cirrhosis, which will be sufficient to diagnose hepatocellular carcinoma. However, a significant number of hepatocellular carcinomas show atypical imaging features, and therefore, are missed at imaging. Dynamic CEUS images are obtained similarly to CT and MRI images. CEUS differentiates between arterial and portal venous phases, in which sonographic hepatocellular carcinoma hallmarks, such as arterial hyperenhancement and subsequent washout appearance, are investigated. The advantages of CEUS over CT and MRI include real-time imaging, use of contrast agents that do not contain iodine and are not nephrotoxic, and quick image acquisition. Despite the advantages, the use of CEUS in the diagnostic algorithm for HCC remains controversial, with disagreement on relevant guidelines. There is no clear evidence of the benefit of surveillance programmes in terms of overall survival as the conflicting results can be a consequence of an inaccurate detection, ineffective treatment, or both. Therefore, assessing the diagnostic accuracy of CEUS may clarify whether the absence of benefit could be related to underdiagnosis. Furthermore, an assessment of the accuracy of CEUS for the diagnosis of hepatocellular carcinoma is needed for either diagnosing hepatocellular carcinoma or ruling it out in people with chronic liver disease who are not included in surveillance programmes.

OBJECTIVES

1. To assess the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma of any size and at any stage in adults with chronic liver disease, in a surveillance programme or in a clinical setting. 2. To assess the diagnostic accuracy of CEUS for the diagnosis of resectable hepatocellular carcinoma in people with chronic liver disease and identify potential sources of heterogeneity in the results.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The last date of search was 5 November 2021.

SELECTION CRITERIA

We included studies assessing the diagnostic accuracy of CEUS for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, with cross-sectional designs, using one of the acceptable reference standards, such as pathology of the explanted liver, and histology of resected or biopsied focal liver lesion with at least a six-month follow-up.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods to screen studies, extract data, and assess the risk of bias and applicability concerns, using the QUADAS-2 checklist. We used the bivariate model and provided estimates of summary sensitivity and specificity. We assessed the certainty of the evidence using GRADE. We presented uncertainty-of-the-accuracy estimates using 95% confidence intervals (CIs).

MAIN RESULTS

We included 23 studies with 6546 participants. Studies were published between 2001 and 2021. We judged all 23 studies at high-risk of bias in at least one domain, and 13/23 studies at high concern for applicability. Most studies used different reference standards to exclude the presence of the target condition. The time interval between the index test and the reference standard was rarely defined. We also had major concerns on their applicability due to the characteristics of the participants. - CEUS for hepatocellular carcinoma of any size and stage: sensitivity 77.8% (95% CI 69.4% to 84.4%) and specificity 93.8% (95% CI 89.1% to 96.6%) (23 studies, 6546 participants; very low-certainty evidence). - CEUS for resectable hepatocellular carcinoma: sensitivity 77.5% (95% CI 62.9% to 87.6%) and specificity 92.7% (95% CI 86.8% to 96.1%) (13 studies, 1257 participants; low-certainty evidence). The observed heterogeneity in the results remains unexplained. The sensitivity analyses, including only studies with clearly prespecified positivity criteria and only studies in which the reference standard results were interpreted with no knowledge of the results about the index test, showed no differences in the results.

AUTHORS' CONCLUSIONS

We found that by using CEUS, as an add-on test following abdominal ultrasound, to diagnose hepatocellular carcinoma of any size and stage, 22% of people with hepatocellular carcinoma would be missed, and 6% of people without hepatocellular carcinoma would unnecessarily undergo further testing or inappropriate treatment. As to resectable hepatocellular carcinoma, we found that 23% of people with resectable hepatocellular carcinoma would incorrectly be unresected, while 8% of people without hepatocellular carcinoma would undergo further inappropriate testing or treatment. The uncertainty resulting from the high risk of bias of the included studies, heterogeneity, and imprecision of the results and concerns on their applicability limit our ability to draw confident conclusions.

Contrast-enhanced ultrasound Liver Imaging Reporting and Data System: Lights and shadows in hepatocellular carcinoma and cholangiocellular carcinoma diagnosis

BACKGROUND

Contrast-enhanced ultrasound (CEUS) is considered a secondary examination compared to computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of hepatocellular carcinoma (HCC), due to the risk of misdiagnosing intrahepatic cholangiocarcinoma (ICC). The introduction of CEUS Liver Imaging Reporting and Data System (CEUS LI-RADS) might overcome this limitation. Even though data from the literature seems promising, its reliability in real-life context has not been well-established yet.

AIM

To test the accuracy of CEUS LI-RADS for correctly diagnosing HCC and ICC in cirrhosis.

METHODS

CEUS LI-RADS class was retrospectively assigned to 511 nodules identified in 269 patients suffering from liver cirrhosis. The diagnostic standard for all nodules was either biopsy (102 nodules) or CT/MRI (409 nodules). Common diagnostic accuracy indexes such as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were assessed for the following associations: CEUS LR-5 and HCC; CEUS LR-4 and 5 merged class and HCC; CEUS LR-M and ICC; and CEUS LR-3 and malignancy. The frequency of malignant lesions in CEUS LR-3 subgroups with different CEUS patterns was also determined. Inter-rater agreement for CEUS LI-RADS class assignment and for major CEUS pattern identification was evaluated.

RESULTS

CEUS LR-5 predicted HCC with a 67.6% sensitivity, 97.7% specificity, and 99.3% PPV (P < 0.001). The merging of LR-4 and 5 offered an improved 93.9% sensitivity in HCC diagnosis with a 94.3% specificity and 98.8% PPV (P < 0.001). CEUS LR-M predicted ICC with a 91.3% sensitivity, 96.7% specificity, and 99.6% NPV (P < 0.001). CEUS LR-3 predominantly included benign lesions (only 28.8% of malignancies). In this class, the hypo-hypo pattern showed a much higher rate of malignant lesions (73.3%) than the iso-iso pattern (2.6%). Inter-rater agreement between internal raters for CEUS-LR class assignment was almost perfect (n = 511, k = 0.94, P < 0.001), while the agreement among raters from separate centres was substantial (n = 50, k = 0.67, P < 0.001). Agreement was stronger for arterial phase hyperenhancement (internal k = 0.86, P < 2.7 × 10^-214; external k = 0.8, P < 0.001) than washout (internal k = 0.79, P < 1.6 × 10^-202; external k = 0.71, P < 0.001).

CONCLUSION

CEUS LI-RADS is effective but can be improved by merging LR-4 and 5 to diagnose HCC and by splitting LR-3 into two subgroups to differentiate iso-iso nodules from other patterns.

Diagnostic performance and interreader agreement of CEUS LI-RADS in ≤ 30 mm liver nodules with different experienced radiologists

PURPOSE

To explore the diagnostic performance and interreader agreement of CEUS LI-RADS in diagnosing ≤ 30 mm liver nodules with different experienced radiologists.

METHODS

Between January 2018 and October 2020, 244 patients at high-risk for HCC who underwent CEUS were enrolled. Two novice radiologists and two expert radiologists independently evaluated LI-RADS categories and main features. Kappa (κ) and Kendall's tests were employed to evaluate the interreader agreement of CEUS LI-RADS. The diagnostic performance was determined based on sensitivity, specificity, accuracy, PPV and NPV.

RESULTS

The interreader agreement for arterial phase hyperenhancement, late and mild washout, early washout, and rim hyperenhancement was moderate to almost perfect (κ, 0.44-0.93) among the different levels of radiologists. The interreader agreement for the LI-RADS categories was substantial to almost perfect (κ, 0.78-0.88). However, the interreader agreement for marked washout was fair to moderate (κ, 0.28-0.50). When CEUS LR-5 was used as a diagnostic criterion for HCC, there were no statistical differences in sensitivity, specificity, accuracy, PPV and NPV among the radiologists (p > 0.05), except for the differences between Reader 4 and the remaining three radiologists in terms of accuracy and sensitivity (p < 0.05).

CONCLUSION

CEUS LI-RADS has good diagnostic agreement for ≤ 30 mm liver nodules among experienced radiologists.

Risk Stratification and Distribution of Hepatocellular Carcinomas in CEUS and CT/MRI LI-RADS: A Meta-Analysis

Background

CEUS LI-RADS and CT/MRI LI-RADS have been used in clinical practice for several years. However, there is a lack of evidence-based study to compare the proportion of hepatocellular carcinomas (HCCs) in each category and the distribution of HCCs of these two categorization systems.

Purpose

The purpose of this study was to compare the proportion of HCCs between corresponding CEUS LI-RADS and CT/MRI LI-RADS categories and the distribution of HCCs and non-HCC malignancies in each category.

Methods

We searched PubMed, Embase, and Cochrane Central databases from January 2014 to December 2021. The proportion of HCCs and non-HCC malignancies and the corresponding sensitivity, specificity, accuracy, diagnostic odds ratio (DOR), and area under the curve (AUC) of the LR-5 and LR-M categories were determined using a random-effect model.

Results

A total of 43 studies were included. The proportion of HCCs in CEUS LR-5 was 96%, and that in CECT/MRI LR-5 was 95% (p > 0.05). The proportion of non-HCC malignancy in CEUS LR-M was lower than that of CT/MRI LR-M (35% vs. 58%, p = 0.01). The sensitivity, specificity, and accuracy of CEUS LR-5 for HCCs were 73%, 92%, and 78%, respectively, and of CT/MRI LR-5 for HCCs, 69%, 92%, and 76%, respectively.

Conclusion

With the upshift of the LI-RADS category, the proportion of HCCs increased. CEUS LR-3 has a lower risk of HCCs than CT/MRI LR-3. CEUS LR-5 and CT/MRI LR-5 have a similar diagnostic performance for HCCs. CEUS LR-M has a higher proportion of HCCs and a lower proportion of non-HCC malignancies compared with CT/MRI LR-M.

Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System in Diagnosing Hepatocellular Carcinoma: Diagnostic Performance and Interobserver Agreement

OBJECTIVES

 To determine the diagnostic performance and inter-reader agreement of the contrast-enhanced ultrasound liver imaging reporting and data system (CEUS-LI-RADS) for diagnosing hepatocellular carcinoma (HCC) in high-risk patients.

METHODS

 In this prospective study, CEUS-LI-RADS categories (LR-5 for predicting HCC) were assigned by six blinded readers and compared to the definitive HCC diagnosis in patients with liver cirrhosis per the 2017 China Liver Cancer Guidelines (CLCG). CEUS features were recorded in 96 patients with 96 histology-proven lesions. The diagnostic performance of LR-5 was described by the sensitivity, specificity and accuracy. Multi-reader agreement was assessed by using intraclass correlation coefficients (ICC).

RESULTS

 In cirrhotic patients, the specificity of LR-5 (range: 92.7-100.0 %) was statistically higher than that of CLCG for each reader (range: 28.6-64.3 %). However, the sensitivity (range: 38.6-63.6 %) and accuracy (range: 53.4-70.7 %) were statistically lower in CEUS-LIRADS than in CLCG (sensitivity range: 88.6-100.0 %; accuracy range: 77.6-86.2 %). Only fair to moderate inter-reader agreement was achieved for the CEUS-LI-RADS category (ICC = 0.595) and washout appearance (ICC range: 0.338 to 0.555). Neither nodule-in-nodule nor mosaic architecture was observed more often in HCC (all P > 0.05), with poor inter-reader consistency for both (both ICC < 0.20).

CONCLUSION

 CEUS-LI-RADS category 5 has a high specificity but a low accuracy for identifying HCC in high-risk patients. Inter-reader agreement is not satisfactory concerning CEUS-LIRADS category and washout appearance. Moreover, the clinical value of ancillary features favoring HCC is quite limited.

Contrast-enhanced ultrasound Liver Imaging Reporting and Data System category M: a systematic review and meta-analysis

PURPOSE

A meta-analysis was conducted to determine the proportion of contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System category M (LR-M) in hepatocellular carcinomas (HCCs) and non-HCC malignancies and to investigate the frequency of individual CEUS LR-M imaging features.

METHODS

The MEDLINE and Embase databases were searched from January 1, 2016 to July 23, 2020 for studies reporting the proportion of CEUS LR-M in HCC and non-HCC malignancies. The meta-analytic pooled proportions of HCC and non-HCC malignancies in the CEUS LR-M category were calculated. The meta-analytic frequencies of CEUS LR-M imaging features in nonHCC malignancies were also determined. Risk of bias and applicability were evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

Twelve studies reporting the diagnostic performance of the CEUS LR-M category were identified, as well as seven studies reporting the frequencies of individual CEUS LR-M imaging features. The pooled proportions of HCC and non-HCC malignancies in the CEUS LR-M category were 54% (95% confidence interval [CI], 44% to 65%) and 40% (95% CI, 28% to 53%), respectively. The pooled frequencies of individual CEUS LR-M imaging features in non-HCC malignancies were 30% (95% CI, 17% to 45%) for rim arterial phase hyperenhancement, 79% (95% CI, 66% to 90%) for early (<60 s) washout, and 42% (95% CI, 21% to 64%) for marked washout.

CONCLUSION

In total, 94% of CEUS LR-M lesions were malignancies, with HCCs representing 54% and non-HCC malignancies representing 40%. The frequencies of individual CEUS LR-M imaging features varied; early washout showed the highest frequency for non-HCC malignancies.

Imaging Diagnosis of HCC: Future directions with special emphasis on hepatobiliary MRI and contrast-enhanced ultrasound

Hepatocellular carcinoma (HCC) is a unique cancer entity that can be noninvasively diagnosed using imaging modalities without pathologic confirmation. In 2018, several major guidelines for HCC were updated to include hepatobiliary contrast agent magnetic resonance imaging (HBA-MRI) and contrast-enhanced ultrasound (CEUS) as major imaging modalities for HCC diagnosis. HBA-MRI enables the achievement of high sensitivity in HCC detection using the hepatobiliary phase (HBP). CEUS is another imaging modality with real-time imaging capability, and it is reported to be useful as a second-line modality to increase sensitivity without losing specificity for HCC diagnosis. However, until now, there is an unsolved discrepancy among guidelines on whether to accept “HBP hypointensity” as a definite diagnostic criterion for HCC or include CEUS in the diagnostic algorithm for HCC diagnosis. Furthermore, there is variability in terminology and inconsistencies in the definition of imaging findings among guidelines; therefore, there is an unmet need for the development of a standardized lexicon. In this article, we review the performance and limitations of HBA-MRI and CEUS after guideline updates in 2018 and briefly introduce some future aspects of imaging-based HCC diagnosis.

Impact of Revision of the LR-M Criteria on the Diagnostic Performance of Contrast-Enhanced Ultrasound LI-RADS

This study was aimed at revising the LI-RADS M category (LR-M) criteria to improve the diagnostic performance categories LR-5 and LR-M of the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) Version 2017. We enrolled 264 patients (264 nodules) with a risk for hepatocellular carcinoma (HCC). The nodules were assigned specific CEUS LI-RADS categories. Washout onset times for all nodules were noted. The diagnostic performance of LR-5 and LR-M was analyzed based on the different early washout criterion for the LR-M category. The positive predictive values in LR-5, LR-4 and LR-3 were 98.6%, 72.2% and 16.7%, respectively, and that for non-HCC malignancies in LR-M was 25.0%. Patients in the LR-M category were reclassified using 45 s as the early washout criterion. LR-5 had higher sensitivity (65.5% vs. 76.2%, p = 0.012) and area under the receiver operating characteristic curve (0.80 vs. 0.85, p = 0.001) for HCC diagnosis after reclassification. LR-M also had higher specificity (71.4% vs. 81.3%, p = 0.010) in diagnosing non-HCC malignancies after reclassification. Our findings suggest CEUS LR-5 is effective for HCC diagnosis. The use of 45 s as the time criterion of early washout for LR-M can improve LR-5 and LR-M performance in the diagnosis of HCC and non-HCC malignancies, respectively.

The Value of Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System in the Diagnosis of Hepatocellular Carcinoma:: A Meta-Analysis

OBJECTIVES

The aim of this study is to systematically evaluate the diagnostic ability of the contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) in hepatocellular carcinoma (HCC).

METHODS

We searched relevant studies from PubMed, Medline, and Embase database. After literature search, duplicate removal, and data extraction, we calculated and analyzed the pooled sensitivity, pooled specificity, pooled odds ratios of diagnostic, pooled likelihood ratio (LR) of positive and negative, and area under the curve (AUC), accuracy, and F1 score to evaluate the diagnostic value of CEUS LI-RADS for HCC.

RESULTS

Thirteen studies and 6491 patients were included in this analysis. The pooled sensitivity and pooled specificity were 0.72 (95% confidence interval [CI], 0.70-0.73) and 0.92 (95% CI, 0.91-0.93), respectively. The positive LR was 8.02 (95% CI, 4.93-13.06) and the negative LR was 0.31 (95% CI, 0.27-0.37). The pooled diagnostic odds ratio was 27.91 (95% CI, 15.39-50.63). The overall AUC was 0.8406 and the accuracy was 0.77.

CONCLUSIONS

CEUS LI-RADS is an effective and promising method to diagnose HCC.

Inter-reader reliability of contrast-enhanced ultrasound Liver Imaging Reporting and Data System: a meta-analysis

PURPOSE

To systematically determine the inter-reader reliability of the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS), with emphasis on its major features for hepatocellular carcinoma (HCC) and LR-M (LI-RADS category M) features for non-HCC malignancy.

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched from January 2016 to March 2021 to identify original articles reporting the inter-reader reliability of CEUS LI-RADS. Meta-analytic pooled kappa values (κ) were calculated for major features [nonrim arterial-phase hyperenhancement (APHE), mild and late washout], LR-M features (rim APHE, early washout), and LI-RADS categorization using the DerSimonian-Laird random-effects model. Meta-regression analysis was performed to explore any causes of study heterogeneity.

RESULTS

Twelve studies with a total of 2862 lesions were included. The meta-analytic pooled κ of nonrim APHE, mild and late washout, rim APHE, early washout, and LI-RADS categorization were 0.73 [95% confidence interval (CI), 0.67 - 0.79], 0.69 (95% CI, 0.54-0.84), 0.54 (95% CI, 0.37-0.71), 0.62 (95% CI, 0.45-0.79), and 0.75 (95% CI, 0.64-0.87), respectively. Compared with the major features, LR-M features had a lower meta-analytic pooled κ. Substantial study heterogeneity was noted in the LI-RADS categorization, and lesion size (p = 0.03) and the homogeneity in reader experience (p = 0.03) were significantly associated with study heterogeneity.

CONCLUSIONS

CEUS LI-RADS showed substantial inter-reader reliability for major features and LI-RADS categorization, but relatively lower reliability was found for LR-M features. In our opinion, the definitions of imaging features require further refinement to improve the inter-reader reliability of CEUS LI-RADS.

Tumor size-based validation of contrast-enhanced ultrasound liver imaging reporting and data system (CEUS LI-RADS) 2017 for hepatocellular carcinoma characterizing

OBJECTIVES

To validate the efficacy of contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) and its major features in diagnosing hepatocellular carcinoma (HCC) of different sizes in high-risk patients.

METHODS

Between January 2014 and December 2015, a total of 545 untreated liver nodules were included. These liver nodules were divided into two groups (<20 mm and ≥20 mm). Each nodule was classified based on CEUS LI-RADS. The diagnostic performance comparison was assessed by the chi-square test, with pathology results as the golden criterion.

RESULTS

The accuracy, sensitivity, specificity, and positive predictive value (PPV) of CEUS LR-5 criteria in <20 mm group vs ≥20 mm group in diagnosing HCC were 60.5% vs 59.8%, 55.6% vs 57.6%, 85.7% vs 88.6 and 95.2% vs 98.5%, respectively, without significant difference (all p > 0.05). The accuracy, sensitivity and PPV of LR5/M for malignancy in <20 mm group were lower than in ≥20 mm group, with values of 79.1% vs 95.0%, 84.2% vs 95.7 and 91.4% vs 99.2%, respectively (p < 0.05).

CONCLUSIONS

The CEUS LI-RADS has a comparable performance for diagnosing HCC between lesions ≥ 20 mm and <20 mm. For diagnosing malignancy including HCC, it has a higher efficacy for lesions ≥ 20 mm than <20 mm.

ADVANCES IN KNOWLEDGE

1.For diagnosing HCC, CEUS LI-RADS has comparable performances between lesions ≥ 20 mm and <20 mm.2. For diagnosing malignancy including HCC, CEUS LI-RADS has a higher efficacy for lesions ≥ 20 mm than <20 mm.

CT/MRI LI-RADS version 2018 versus CEUS LI-RADS version 2017 in the diagnosis of primary hepatic nodules in patients with high-risk hepatocellular carcinoma

Background

This study aimed to explore the application value of computed tomography/magnetic resonance imaging (CT/MRI) liver imaging reporting and data system (LI-RADS) version 2018 and contrast-enhanced ultrasound (CEUS) LI-RADS version 2017 in high-risk hepatocellular carcinoma (HCC) patients and to conduct a comparative analysis.

Methods

This study enrolled 250 high-risk HCC patients with 259 primary hepatic nodules from June 2017 to June 2020. Two investigators used a single-blind method to classify all nodules. The u-test, t-test, and Kappa test were performed. The sensitivity, specificity, positive predictive value (PPV), negative predictive value and receiver operating characteristic curves of LR-5 and LR-M in the diagnosis of HCC and non-HCC malignancy were respectively calculated.

Results

CT/MRI LI-RADS v2018 and CEUS LI-RADS v2017 showed substantial agreement inter-observers, and there was a moderate agreement inter-modality. The specificity and PPV of HCC and non-HCC malignancies in CT/MRI LR-5/M were higher than CEUS. The areas under the curve (AUC) of CT/MRI LR-5 and LR-M were 0.794 and 0.777, and the AUC of CEUS LR-5 and LR-M were 0.720 and 0.718, respectively.

Conclusions

Two modalities have substantial agreement inter-observers and moderate agreement inter-modalities. The diagnostic accuracy of HCC of CT/MRI LR-5 and non-HCC malignancy of CT/MRI LR-M are higher than CEUS.

Does Training in LI-RADS Version 2018 Improve Readers' Agreement with the Expert Consensus and Inter-reader Agreement in MRI Interpretation?

BACKGROUND

The Liver Imaging Reporting and Data System (LI-RADS) was established for noninvasive diagnosis for hepatocellular carcinoma (HCC). However, whether training can improve readers' agreement with the expert consensus and inter-reader agreement for final categories is still unclear.

PURPOSE

To explore training effectiveness on readers' agreement with the expert consensus and inter-reader agreement.

STUDY TYPE

Prospective.

SUBJECTS

Seventy lesions in 61 patients at risk of HCC undergoing liver MRI; 20 visiting scholars.

FIELD STRENGTH/SEQUENCE

1.5 T or 3 T, Dual-echo T₁ WI, Fast spin-echo T₂ WI, SE-EPI DWI, and Dynamic multiphase fast gradient-echo T₁ WI.

ASSESSMENT

Seventy lesions assigned LI-RADS categories of LR1-LR5, LR-M, and LR-TIV by three radiologists in consensus were randomly selected, with 10 cases for each category. The consensus opinion was the standard reference. The third radiologist delivered the training. Twenty readers reviewed images independently and assigned each an LI-RADS category both before and after the training.

STATISTICAL TESTS

Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, receiver operating characteristic (ROC) analysis, simple and weighted kappa statistics, and Fleiss kappa statistics.

RESULTS

Before and after training: readers' AUC (areas under ROC) for LR-1-LR-5, LR-M, and LR-TIV were 0.898 vs. 0.913, 0.711 vs. 0.876, 0.747 vs. 0.860, 0.724 vs. 0.815, 0.844 vs. 0.895, 0.688 vs. 0.873, and 0.720 vs. 0.948, respectively, and all improved significantly (P < 0.05), except LR-1(P = 0.25). Inter-reader agreement between readers for LR-1-LR-5, LR-M, LR-TIV were 0.725 vs. 0.751, 0.325 vs. 0.607, 0.330 vs. 0.559, 0.284 vs. 0.488, 0.447 vs. 0.648, 0.229 vs. 0.589, and 0.362 vs. 0.852, respectively, and all increased significantly (P < 0.05). For training effectiveness on both AUC and inter-reader agreement, LR-TIV, LR-M, and LR-2 improved most, and LR-1 made the least.

DATA CONCLUSION

This study shows LI-RADS training could improve reader agreement with the expert consensus and inter-reader agreement for final categories.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2.

Can Risk Stratification Based on Ultrasound Elastography of Background Liver Assist CEUS LI-RADS in the Diagnosis of HCC?

Objective

To explore whether risk stratification based on ultrasound elastography of liver background assists contrast-enhanced ultrasound liver imaging reporting and data system (CEUS LI-RADS) in diagnosing HCC.

Materials and Methods

In total, 304 patients with focal liver lesions (FLLs) confirmed by pathology underwent CEUS and ultrasound elastography were included in this retrospective study. Patients with chronic hepatitis B (CHB, n=193) and non-CHB (n=111) were stratified by four liver stiffness measurement (LSM) thresholds. A LI-RADS category was assigned to FLLs using CEUS LI-RADS v2017. The diagnostic performance was assessed with the AUC, sensitivity, specificity, PPV, and NPV.

Results

The mean background liver stiffness of HCC patients with CHB, HCC patients without CHB and non-HCC patients without CHB were 9.72 kPa, 8.23 kPa and 4.97 kPa, respectively. The AUC, sensitivity, specificity and PPV of CEUS LI-RADS for HCC in CHB patients with LSM ≥ 5.8 kPa, ≥ 6.8 kPa, ≥ 9.1 kPa, and ≥ 10.3 kPa were high, with corresponding values of 0.745 to 0.880, 94.2% to 95.3%, 81.3% to 85.7%, and 98.1% to 98.8%, respectively. Higher AUC and specificity for HCC was observed in non-CHB patients with LSM ≥ 9.1 kPa and ≥ 10.3 kPa compared to non-CHB patients with LSM ≥ 5.8 kPa and ≥ 6.8 kPa, with corresponding values of0.964/1.000 vs 0.590/0.580, and 100%/100% vs 60%/70%, respectively.

Conclusion

CEUS LI-RADS has a good diagnostic performance in CHB patients regardless of the background liver stiffness. Furthermore, CEUS LI-RADS can be applied for non-CHB patients with a LSM ≥ 9.1 kPa.

Diagnostic performance of intravascular perfusion based contrast-enhanced ultrasound LI-RADS in the evaluation of hepatocellular carcinoma

BACKGROUND

The contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) is a relative new algorithm for hepatocellular carcinoma (HCC) assessment.

OBJECTIVE

To validate the diagnostic efficiency of the intravascular perfusion based CEUS LI-RADS for HCC.

METHODS

Archives of 873 patients with focal liver lesions (FLLs) undergoing CEUS were reviewed, and target images were read by two sonologists independently according to the CEUS LI-RADS. The diagnostic performance was calculated and compared.

RESULTS

Assessment with reference to CEUS LI-RADS, 87 of 218 FLLs (39.9%) were categorized as LR-5, 131 of 218 FLLs (60.1%) were categorized as non-LR-5, 19 of 99 HCCs were categorized as non-LR-5, and 7 of 119 non-HCCs were categorized as LR-5. The sensitivity, specificity, AUROC, positive and negative predictive values of CEUS LI-RADS for diagnosing HCC were 80.81%(95%CI: 71.7%-88.0%), 94.1%(95%CI: 88.3%-97.6%), 0.87 (95%CI: 0.82-0.92), 91.9%(95%CI: 84.1%-96.7%), and 85.5%(95%CI: 78.3%-91.0%), respectively.

CONCLUSIONS

The diagnostic efficiency of the intravascular perfusion based CEUS LI-RADS for the evaluation of HCCs is very good.

Inter-reader agreement of CEUS LI-RADS among radiologists with different levels of experience

OBJECTIVES

To investigate the inter-reader agreement of contrast-enhanced ultrasound (CEUS) of Liver Imaging Reporting and Data System version 2017 (LI-RADS v2017) categories among radiologists with different levels of experience.

MATERIALS AND METHODS

From January 2014 to December 2014, a total of 326 patients at high risk of hepatocellular carcinoma (HCC) who underwent CEUS were included in this retrospective study. All lesions were classified according to LI-RADS v2017 by six radiologists with different levels of experiences: two residents, two fellows, and two specialists. Kappa coefficient was used to assess consistency of LI-RADS categories and major features among radiologists with different levels of experience. The diagnostic performance of HCC was described by accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC).

RESULTS

Inter-reader agreement among radiologists of different experience levels was substantial agreement for arterial phase hyperenhancement, washout appearance, and early or late washout. Inter-reader agreement for LI-RADS categories was moderate to substantial. When LR-5 was used as criteria to determinate HCC, the AUC of LI-RADS for HCC was 0.67 for residents, 0.72 for fellows, and 0.78 for specialist radiologists. When compared between residents and specialists, accuracy, sensitivity, and AUC were significantly different (all p < 0.05). However, there were no significant differences in specificity, PPV, and NPV between the two groups.

CONCLUSION

CEUS LI-RADS showed good diagnostic consistency among radiologists with different levels of experience, and consistency increased with experience levels.

KEY POINTS

• The inter-reader agreement for LI-RADS categories was moderate to substantial agreement (κ, 0.60-0.80). • When compared between residents and specialists, accuracy, sensitivity, and AUC showed significantly different (all p < 0.05). However, there were no significant differences for specificity, PPV, and NPV between these two groups. • Among the radiologists with more than 1 year of experience, there was no significant difference in the diagnostic performance of HCC, suggesting that CEUS LI-RADS is a good standardized categorization system for high-risk patients.

Clinical Application of Liver Imaging Reporting and Data System for Characterizing Liver Neoplasms: A Meta-Analysis

The Liver Imaging Reporting and Data System (LI-RADS) is a comprehensive system for standardizing liver imaging in patients at risk of developing hepatocellular carcinoma (HCC). We aimed to determine the diagnostic performance of LI-RADS category 5 (LR5) for diagnosing HCC and LI-RADS category M (LRM) for characterizing other non-HCC malignancies (OM) using contrast-enhanced ultrasound (CEUS) and computed tomography (CT)/magnetic resonance imaging (MRI). Multiple databases were searched for articles evaluating the diagnostic accuracy of CEUS LI-RADS and/or CT/MRI LI-RADS. A random-effects model was adopted to synthesize the summary estimates of the diagnostic accuracy of LR5 for diagnosing HCC and LRM for characterizing OM using CEUS and CT/MRI. The pooled sensitivity and specificity of CEUS LR5 for the diagnosis of HCC were 69% and 93%, respectively. The pooled sensitivity was 67% and the specificity, 93% of CT/MRI LR5 for HCC diagnosis. There was no significant difference between the overall diagnostic accuracy for HCC diagnosis of CEUS LR5 and that of CT/MRI LR5 in terms of diagnostic odds ratio (DOR) (p = 0.55). The sensitivity was 84% with a specificity of 90% in the CEUS LRM for characterizing OM, while the sensitivity and specificity of CT/MRI LRM for characterizing OM was 63% and 95%. The DOR of CEUS LRM for characterizing OM was higher than that of CT/MRI LRM without significant difference (50.59 vs. 36.06, p = 0.34). This meta-analysis indicated that CEUS LI-RADS is qualified to characterize HCC and OM and may provide complementary information on liver nodules to CT/MRI LI-RADS.

Diagnostic Accuracy of Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) for Differentiating Between Hepatocellular Carcinoma and Other Hepatic Malignancies in High-Risk Patients: A Meta-Analysis

OBJECTIVES

 The American College of Radiology (ACR) contrast-enhanced ultrasound liver imaging reporting and data system (CEUS LI-RADS), which includes diagnostic criteria for hepatocellular carcinoma (HCC) and other hepatic malignancies (OM), is increasingly used in clinical practice. This study performed a meta-analysis to assess the diagnostic accuracy of CEUS LI-RADS for differentiating between HCC and OM in high-risk patients.

METHODS

 PubMed, Embase (Ovid), and Cochrane (CENTRAL) were searched for relevant studies. All studies that reported the percentage of HCC and OM in the LI-RADS categories were included. Random-effects models were used to calculate the pooled sensitivity and specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve.

RESULTS

 Eight studies involving 4215 focal liver lesions were included in the final analysis. The pooled sensitivity and specificity of the LR-5 criteria for HCC were 0.71 (95 % CI, 0.69-0.72) and 0.88 (0.85-0.91), respectively, the DOR was 18.36 (7.41-45.52), and the area under the SROC curve (AUC) was 0.8128. The pooled sensitivity and specificity of the LR-M criteria for OMs were 0.85 (0.81-0.88) and 0.86 (0.85-0.87), the DOR was 27.82 (11.83-65.40), respectively, and the SROC AUC was 0.9098.

CONCLUSION

 The CEUS LI-RADS can effectively distinguish HCC from other hepatic malignancy in high-risk patients based on LR-5 criteria and LR-M criteria. However, further studies are needed for validation due to the limited number of included studies and the potential heterogeneity among the included studies.

Accuracy of contrast-enhanced ultrasound liver imaging reporting and data system: a systematic review and meta-analysis

BACKGROUND AND AIM

After the introduction of the contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS), several studies have reported on its performance, but the reported data vary considerably. Therefore, we performed a systematic review and meta-analysis to determine the diagnostic performance of CEUS LI-RADS in patients at risk for hepatocellular carcinoma (HCC) and investigate the causes of study heterogeneity.

METHODS

Original studies published until May 30, 2020, investigating the diagnostic performance of CEUS LI-RADS were identified in the MEDLINE, EMBASE, and Cochrane library databases. Study quality was assessed using the QUADAS-2 tool. Meta-analytic summary sensitivity and specificity for the diagnosis of HCC were calculated using a bivariate random-effects model. Meta-regression analysis was performed to explore the causes of study heterogeneity.

RESULTS

Of the 105 articles screened, eight studies were finally analyzed (5428 hepatic observations). The summary sensitivity and specificity of CEUS LI-RADS category 5 (LR-5) for diagnosing HCC were 73% [95% confidence interval (CI) 65-79%; I² = 93%] and 95% (95% CI 91-97%; I² = 89%), respectively. Substantial study heterogeneity was noted in both sensitivity and specificity. Study heterogeneity was significantly associated with the proportion of cases of HCC and the type of reference standard (p ≤ 0.05).

CONCLUSION

CEUS LI-RADS had high pooled specificity for diagnosing HCC but suboptimal pooled sensitivity. Substantial study heterogeneity was found, which was significantly associated with the proportion of cases of HCC and the type of reference standard.

Imaging Diagnosis of Hepatocellular Carcinoma: The Liver Imaging Reporting and Data System, Why and How?

The Liver Imaging Reporting and Data System (LI-RADS) provides standardized lexicon, technique, interpretation, and reporting of liver imaging in patients at risk for hepatocellular carcinoma (HCC). When applied to at-risk populations, LI-RADS achieves higher than 95% positive predictive value for the noninvasive diagnosis of HCC on computed tomography (CT), MRI and contrast-enhanced ultrasound (CEUS). This article focuses on similarities and differences between the CT/MRI diagnostic algorithm (CT/MRI LI-RADS) and the CEUS diagnostic algorithm (CEUS LI-RADS) to inform health care professionals for efficient and appropriate clinical decisions through the management of patients at risk.

Contrast-enhanced ultrasound liver imaging reporting and data system for diagnosing hepatocellular carcinoma: A meta-analysis

BACKGROUND & AIMS

Contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) is a comprehensive system for standardizing CEUS at high risk for hepatocellular carcinoma (HCC). We performed a meta-analysis to determine the diagnostic performance of the CEUS LR-5 for HCC and the pooled proportions of HCCs in each CEUS LI-RADS category.

METHODS

We searched multiple databases for studies reporting the diagnostic accuracy of the CEUS LI-RADS. Random-effects model was used to determine summary estimates of the diagnostic performance of CEUS LR-5 and the pooled proportions of HCCs in each CEUS LI-RADS category. Risk of bias and concerns regarding applicability were evaluated with the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

Eleven studies were included in the final analysis, which consisted of 5535 observations with 3983 HCCs. The pooled per-observation sensitivity and specificity of the CEUS LR-5 for diagnosing HCC were 69% (95% confidence interval [CI], 64%-73%) and 92% (95% CI, 83%-96%) respectively. The pooled proportions of HCCs were 0% (95% CI, 0-0%) for LR-1, 1% (95% CI, 0%-4%) for CEUS LR-2, 26% (95% CI, 14%-39%) for CEUS LR-3, 77% (95% CI, 68%-86%) for CEUS LR-4, 97% (95% CI, 95%-98%) for CEUS LR-5, 57% (95% CI, 44%-69%) for CEUS LR-M and 100% (95% CI, 93%-100%) for CEUS LR-5V or TIV.

CONCLUSIONS

The CEUS LR-5 category showed moderate sensitivity and high specificity for diagnosing HCC. The proportion of HCCs was higher in the higher CEUS LI-RADS categories.