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

Dynamic Contrast-Enhanced Ultrasonography Combined With LR-M Classification Criteria for Differentiating Malignant Liver Nodules at High Risk for Hepatocellular Carcinoma

OBJECTIVE

We aimed to investigate the value of quantitative parameters derived from dynamic contrast-enhanced ultrasonography (DCE-US) and a combination of these quantitative parameters with the LR-M classification criteria in distinguishing hepatocellular carcinoma (HCC) nodules and non-HCC malignancies.

METHODS

HCC and non-HCC malignant nodules were grouped using pathologic results, and each nodule was classified using CEUS LI-RADS 2017. Quantitative CEUS analysis of each nodule was performed using VueBox, and quantitative parameters were compared between the HCC and non-HCC groups. The diagnostic efficacy of the LR-5 category for HCC was analyzed using the LR-M classification criteria along with time-related quantitative parameters.

RESULTS

Of the 190 malignant liver nodules, 137 and 53 were HCCs and non-HCC malignancies, respectively. The median values of quantitative parameters RT (rise time), TTP (time to peak), mTTl (mean transit time local), and FT (fall time) in the non-HCC malignant group were lower than those in the HCC group, with p < 0.05. There was a statistically significant difference in WiAUC (wash-in area under the curve), WoAUC (wash-out area under the curve), WiWoAUC (wash-in and wash-out area under the curve), and WoR (wash-out rate) values between HCC and non-HCC malignant groups, with p < 0.05. Using LR-M washout time <60 s and FT ≤21.2 s as the new diagnostic standard, the LR-5 category showed a sensitivity of 83.9%, specificity of 96.2%, and positive predictive value of 98.3% for HCC diagnosis.

CONCLUSION

DCE-US can facilitate the distinction of HCCs and non-HCC malignancies. Non-HCC malignancies present with earlier peak enhancement and more rapid and marked washout than HCC nodules. The combination of the LR-M classification criteria and FT ≤21.2 s can significantly improve the diagnostic sensitivity of the LR-5 category for HCC.

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.

Combining serum AFP and CEUS LI-RADS for better diagnostic performance in Chinese high-risk patients

PURPOSE

To evaluate and compare the diagnostic performance of revised contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System version by combining LR-M category and serum alpha-fetoprotein (AFP) under different cut-off values.

MATERIAL AND METHODS

This retrospective study enrolled 152 high-risk patients with 152 histology-proven nodules. For revised LI-RADS, nodules in LR-M with different elevated AFP thresholds have been reclassified as the LR-5 category. The diagnostic performances of original and revised CEUS LI-RADS were evaluated and compared.

RESULTS

To compare with the original version, the sensitivity of revised LR-5 (adjusted with AFP value > 200 ng/ml or 400 ng/ml) for the diagnosis of hepatocellular carcinoma (HCC) improved from 52.5 to 69.2% or 65.0%, respectively (both p < 0.001) without compromising specificity (87.5% vs. 71.9% or 78.1%, respectively, both p > 0.05). For the diagnosis of non-HCC malignancy, the specificity of the LR-M after reclassification was improved (69.6% vs. 84.4% or 80.7%, respectively, both p < 0.001) with a non-significant sensitivity reduction (100.0 vs. 70.6% or 82.4%, respectively, both p > 0.05). After modification, the sensitivity of LR-5 also increased to 69.1% or 64.9% (both p < 0.001), while the specificity and PPV did not change (both p > 0.05) for larger nodules (> 20 mm).

CONCLUSION

The diagnostic performance of CEUS LI-RADS can be further improved by reclassifying LR-M nodules with elevated AFP thresholds to LR-5.

The diagnostic performance of contrast-enhanced CT versus extracellular contrast agent-enhanced MRI in detecting hepatocellular carcinoma: direct comparison and a meta-analysis

To compare the diagnostic value of contrast-enhanced computed tomography (CT) with extracellular contrast agent-enhanced magnetic resonance imaging (ECA-MRI) for the detection of hepatocellular carcinoma (HCC). Pubmed, Embase, Web of Science and Cochrane Library were searched (1/5/2021) for studies comparing contrast-enhanced CT with ECA-MRI in patients suspected of HCC. Studies without head-to-head comparison were excluded. The pooled sensitivity, specificity and summary area under the curve (sAUC) of contrast-enhanced CT and ECA-MRI in detecting HCC was calculated based on bivariate random effects model. Heterogeneity test included threshold effect analysis and meta-regression. Subgroup analyses were conducted according to lesion size (< 20 mm or ≥ 20 mm). Overall, 10 articles containing 1333 patients were deemed suitable for inclusion in this meta-analysis. ECA-MRI displayed increased sensitivity to contrast-enhanced CT in detecting HCC (0.77 vs. 0.63, P < 0.01). The difference in specificity between ECA-MRI and contrast-enhanced CT was not statistically significant (0.93 vs. 0.94, P = 0.25). ECA-MRI yielded higher diagnostic accuracy (sAUCs = 0.88 vs. 0.80, P < 0.01). In the subgroup analysis with a lesion size < 20 mm, ECA-MRI allowed significant gains of accuracy compared to contrast-enhanced CT (0.79 vs. 0.72, P = 0.02). ECA-MRI also outperformed contrast-enhanced CT in patients with lesion size ≥ 20 mm (sAUCs = 0.96 vs. 0.93, P = 0.04). ECA-MRI provided higher sensitivity and accuracy than contrast-enhanced CT in detecting HCC, especially lesions size < 20 mm.

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.

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.

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.

A Nomogram Based on Combining Clinical Features and Contrast Enhanced Ultrasound LI-RADS Improves Prediction of Microvascular Invasion in Hepatocellular Carcinoma

PURPOSES

To establish a predictive model incorporating clinical features and contrast enhanced ultrasound liver imaging and reporting and data system (CEUS LI-RADS) for estimation of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) patients.

METHODS

In the retrospective study, 127 HCC patients from two hospitals were allocated as training cohort (n=98) and test cohorts (n=29) based on cutoff time-point, June 2020. Multivariate regression analysis was performed to identify independent indicators for developing predictive nomogram models. The area under receiver operating characteristic (AUC) curve was also determined to establish the diagnostic performance of different predictive models. Corresponding sensitivities and specificities of different models at the cutoff nomogram value were compared.

RESULTS

In the training cohort, clinical information (larger tumor size, higher AFP level) and CEUS LR-M were significantly correlated with the presence of MVI (all p<0.05). By incorporating clinical information and CEUS LR-M, the predictive model (LR-M+Clin) achieved a desirable diagnostic performance (AUC=0.80 and 0.84) in both cohorts at nomogram cutoff score value of 89. The sensitivity of LR-M+Clin when predicting MVI in HCC patients was higher than that of the clinical model alone (86.7% vs. 46.7%, p=0.027), while specificities were 78.6% and 85.7% (p=0.06), respectively, in the test cohort. In addition, LR-M+Clin exhibited similar AUC and specificity, but a significantly higher sensitivity (86.7%) than those of LR-M alone and LR-5(No)+Clin (both sensitivities=73.3%, both p=0.048).

CONCLUSION

The predictive model incorporating CEUS LR-M and clinical features was able to predict the MVI status of HCC and is a potential reliable preoperative tool for informing treatment.