Contrast-enhanced ultrasound LI-RADS 2017: comparison with CT/MRI LI-RADS

Performance of LI-RADS category 5 vs combined categories 4 and 5: a systemic review and meta-analysis

OBJECTIVE

Computed tomography (CT)/magnetic resonance imaging (MRI) Liver Imaging Reporting and Data System (LI-RADS, LR) category 5 has high specificity and modest sensitivity for diagnosis of hepatocellular carcinoma (HCC). The purpose of this study was to compare the diagnostic performance of LR-5 vs combined LR-4 and LR-5 (LR-4/5) for HCC diagnosis.

METHODS

MEDLINE and EMBASE databases through January 03, 2023 were searched for studies reporting the performance of LR-5 and combined LR-4/5 for HCC diagnosis, using CT/MRI LI-RADS version 2014, 2017, or 2018. A bivariate random-effects model was used to calculate the pooled per-observation diagnostic performance. Subgroup analysis was performed based on imaging modalities and type of MRI contrast material.

RESULTS

Sixty-nine studies (15,108 observations, 9928 (65.7%) HCCs) were included. Compared to LR-5, combined LR-4/5 showed significantly higher pooled sensitivity (83.0% (95% CI [80.3-85.8%]) vs 65.7% (95% CI [62.4-69.1%]); p < 0.001), lower pooled specificity (75.0% (95% CI [70.5-79.6%]) vs 91.7% (95% CI [90.2-93.1%]); p < 0.001), lower pooled positive likelihood ratio (3.60 (95% CI [3.06-4.23]) vs 6.18 (95% CI [5.35-7.14]); p < 0.001), and lower pooled negative likelihood ratio (0.22 (95% CI [0.19-0.25]) vs 0.38 (95% CI [0.35-0.41]) vs; p < 0.001). Similar results were seen in all subgroups.

CONCLUSIONS

Our meta-analysis showed that combining LR-4 and LR-5 would increase sensitivity but decrease specificity, positive likelihood ratio, and negative likelihood ratio. These findings may inform management guidelines and individualized management.

CLINICAL RELEVANCE STATEMENT

This meta-analysis estimated the magnitude of changes in the sensitivity and specificity of imaging criteria when LI-RADS categories 4 and 5 were combined; these findings can inform management guidelines and individualized management.

KEY POINTS

There is no single worldwide reporting system for liver imaging, partly due to regional needs. Combining LI-RADS categories 4 and 5 increased sensitivity and decreased specificity and positive and negative likelihood ratios. Changes in the sensitivity and specificity of imaging criteria can inform management guidelines and individualized management.

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.

Is concurrent LR-5 associated with a higher rate of hepatocellular carcinoma in LR-3 or LR-4 observations? An individual participant data meta-analysis

BACKGROUND

The Liver Imaging Reporting and Data System (LI-RADS) does not consider factors extrinsic to the observation of interest, such as concurrent LR-5 observations.

PURPOSE

To evaluate whether the presence of a concurrent LR-5 observation is associated with a difference in the probability that LR-3 or LR-4 observations represent hepatocellular carcinoma (HCC) through an individual participant data (IPD) meta-analysis.

METHODS

Multiple databases were searched from 1/2014 to 2/2023 for studies evaluating the diagnostic accuracy of CT/MRI for HCC using LI-RADS v2014/2017/2018. The search strategy, study selection, and data collection process can be found at https://osf.io/rpg8x . Using a generalized linear mixed model (GLMM), IPD were pooled across studies and modeled simultaneously with a one-stage meta-analysis approach to estimate positive predictive value (PPV) of LR-3 and LR-4 observations without and with concurrent LR-5 for the diagnosis of HCC. Risk of bias was assessed using a composite reference standard and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2).

RESULTS

Twenty-nine studies comprising 2591 observations in 1456 patients (mean age 59 years, 1083 [74%] male) were included. 587/1960 (29.9%) LR-3 observations in 1009 patients had concurrent LR-5. The PPV for LR-3 observations with concurrent LR-5 was not significantly different from the PPV without LR-5 (45.4% vs 37.1%, p = 0.63). 264/631 (41.8%) LR-4 observations in 447 patients had concurrent LR-5. The PPV for LR-4 observations with concurrent LR-5 was not significantly different from LR-4 observations without concurrent LR-5 (88.6% vs 69.5%, p = 0.08). A sensitivity analysis for low-risk of bias studies (n = 9) did not differ from the primary analysis.

CONCLUSION

The presence of concurrent LR-5 was not significantly associated with differences in PPV for HCC in LR-3 or LR-4 observations, supporting the current LI-RADS paradigm, wherein the presence of synchronous LR-5 may not alter the categorization of LR-3 and LR-4 observations.

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.

The comparison of contrast-enhanced ultrasound and gadoxetate disodium-enhanced MRI LI-RADS for nodules ≤2 cm in patients at high risk for HCC: a prospective study

Objectives

To investigate the consistency of LI-RADS of CEUS and EOB-MRI in the categorization of liver nodules ≤2cm in patients at high risk for HCC.

Methods

Patients at high risk for HCC with nodules ≤2cm who underwent CEUS and EOB-MRI in our hospital were prospectively enrolled. The CEUS images and EOB-MRI imaging of each liver nodule were observed to evaluate inter-observer consistency and category according to CEUS LI-RADS V2017 and CT/MRI LI-RADS V2017 criteria double blinded. Pathology and/or follow-up were used as reference standard.

Results

A total of 127 nodules in 119 patients met the inclusion criteria. The inter-observer agreement was good on CEUS and EOB-MRI LI-RADS (kappa = 0.76, 0.76 p < 0.001). The inter-modality agreement was fair (kappa=0.21, p < 0.001). There was no statistical difference in PPV and specificity between CEUS and EOB-MRI LR-5 for HCC, while the difference in AUC was statistically significant. We used new criteria (CEUS LR-5 and EOB-MRI LR-4/5 or CEUS LR-4/5 and EOB-MRI LR-5) to diagnose HCC. The sensitivity, specificity, and AUC of this criteria was 63.4%, 95.6%, and 0.80.

Conclusions

CEUS and EOB-MRI showed fair inter-modality agreement in LI-RADS categorization of nodules ≤2 cm. The inter-observer agreement of CEUS and EOB-MRI LI-RADS were substantial. CEUS and EOB-MRI LR-5 have equally good positive predictive value and specificity for HCC ≤ 2cm, and combining these two modalities may better diagnose HCC ≤ 2 cm.

Clinical Trial Registration

https://clinicaltrials.gov/, identifier NCT04212286.

Evaluation of the Time Difference Method in Identifying Hepatocellular Carcinoma in Current CEUS LR-M Category Nodules

OBJECTIVE

The aim of the work described here was to explore a potential method for improving the diagnostic detection of hepatocellular carcinoma (HCC) based on the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) Version 2017.

METHODS

We retrospectively evaluated 585 liver nodules in 427 patients at risk for HCC from December 2020 to March 2023. The nodules were categorized as LR-1 to LR-M based on CEUS LI-RADS Version 2017 and were randomly subclassified into a developmental cohort (DC) and a validation cohort (VC) at 3:1. In the DC, the cutoff value of the time difference (∆T) for differentiating HCC from other malignancies by LR-M was calculated and used to reclassify nodules in the VC. The diagnostic effect on HCC detection before and after reclassification was further assessed.

RESULTS

According to the current CEUS LI-RADS, 140 of 426 (32.9%) confirmed HCC nodules were misclassified as LR-M. In the DC (439 nodules), the receiver operating characteristic (ROC) curve revealed that the cutoff value of ∆T (wash-out onset time minus contrast arrival time) recommended for HCC diagnosis was greater than 21 s. In the VC (146 nodules), 34 HCCs were correctly categorized as LR-5 according to the cutoff value, and after reclassification, LR-5 had higher accuracy (67.1% vs. 89.0%, p < 0.001) and sensitivity (56.0% vs. 87.2%, p < 0.001) for HCC diagnosis with high specificity (100% vs. 94.6%, p = 0.500).

CONCLUSION

Using the time difference method could identify HCC nodules misdiagnosed as LR-M and improve the diagnostic performance of current CEUS LI-RADS.

Development and Comparison of Prediction Models Based on Sonovue- and Sonazoid-Enhanced Ultrasound for Pathologic Grade and Microvascular Invasion in Hepatocellular Carcinoma

OBJECTIVE

This study was aimed at developing and comparing prediction models based on Sonovue and Sonazoid contrast-enhanced ultrasound (CEUS) in predicting pathologic grade and microvascular invasion (MVI) of hepatocellular carcinoma (HCC). Also investigated was whether Kupffer phase images have additional predictive value for the above pathologic features.

METHODS

Ninety patients diagnosed with primary HCC who had undergone curative hepatectomy were prospectively enrolled. All patients underwent conventional ultrasound (CUS), Sonovue-CEUS and Sonazoid-CEUS examinations pre-operatively. Clinical, radiologic and pathologic features including pathologic grade, MVI and CD68 expression were collected. We developed prediction models comprising clinical, CUS and CEUS (Sonovue and Sonazoid, respectively) features for pathologic grade and MVI with both the logistic regression and machine learning (ML) methods.

RESULTS

Forty-one patients (45.6%) had poorly differentiated HCC (p-HCC) and 37 (41.1%) were MVI positive. For pathologic grade, the logistic model based on Sonazoid-CEUS had significantly better performance than that based on Sonovue-CEUS (area under the curve [AUC], 0.929 vs. 0.848, p = 0.035), whereas for MVI, these two models had similar accuracy (AUC, 0.810 vs. 0.786, p = 0.068). Meanwhile, we found that well-differentiated HCC tended to have a higher enhancement ratio in 6-12 min during the Kupffer phase of Sonazoid-CEUS, as well as higher CD68 expression compared with p-HCC. In addition, all of these models can effectively predict the risk of recurrence (p < 0.05).

CONCLUSION

Sonovue-CEUS and Sonazoid-CEUS were comparably excellent in predicting MVI, while Sonazoid-CEUS was superior to Sonovue-CEUS in predicting pathologic grade because of the Kupffer phase. The enhancement ratio in the Kupffer phase has additional predictive value for pathologic grade prediction.

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.

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.

Intrahepatic splenosis: Contrast enhanced ultrasound and magnetic resonance imaging findings

OBJECTIVE

To evaluate the contrast enhanced ultrasound (CEUS) and contrast enhanced magnetic resonance imaging (CEMRI) features of intrahepatic splenosis (IHS).

METHODS & MATERIALS

Five patients (three males and two females, median age, 44 years; range,32-73 years) with seven IHSs were retrieved from the database of our hospital from March 2012 to October 2021. All IHSs were confirmed histologically by surgery. The CEUS and CEMRI characteristics of individual lesion were fully analyzed.

RESULTS

All IHS patients were asymptomatic and four out of five patients had history of splenectomy. On CEUS, all IHSs were hyperenhancement in arterial phase. 71.4% (5/7) of IHSs manifested overall filling within few seconds, the other two lesions showed centripetal filling. Subcapsular vascular hyperenhancement and feeding artery was seen in 28.6% (2/7) and 42.9% (3/7) of IHSs, respectively. During portal venous phase, IHSs presented hyperenhancement (2/7) or isoenhancement (5/7). Moreover, rim-like hypoenhanced area was uniquely observed surrounding 85.7% (6/7) of IHSs. In late phase, seven IHSs remained continuous hyper- or isoenhancement. On CEMRI, five IHSs showed mosaic hyperintense in early arterial phase, the other two lesions showed homogeneous hyperintense. In portal venous phase, all IHSs revealed continuous hyper- (71.4%, 5/7) or iso-intense (28.6%, 2/7). During late phase, one IHS (14.3%, 1/7) became hypointense, the other lesions remained hyper- or isointense.

CONCLUSION

Diagnosis of IHS can be based on typical CEUS and CEMRI features in patients with history of splenectomy.

CEUS and CT/MRI LI-RADS in Association With Serum Biomarkers for Differentiation of Combined Hepatocellular-Cholangiocarcinoma From Hepatocellular Carcinoma

Background

Combined Hepatocellular-cholangiocarcinoma (cHCC-CCAs) are with both unambiguously differentiated hepatocellular and biliary components. cHCC-CCAs show various imaging features similar to hepatocellular carcinoma (HCCs) and intrahepatic cholangiocarcinoma (ICCs), which makes the differential diagnosis between them challenging. The accurate diagnosis of cHCC-CCAs is of great importance in selecting treatment methods and performing patient management.

Purpose

To investigate the diagnostic efficacy of CEUS and CT/MRI LI-RADS in association with tumor biomarkers for differentiation of cHCC-CCAs from HCCs.

Methods

A total of 54 cHCC-CCAs and 55 HCCs in two centers were retrospectively collected. The diagnostic criteria for cHCC-CCAs if one or more of the following conditions were satisfied: (1) arterial phase hyperenhancement (APHE) on CEUS and LR-M on CT/MRI; (2) LR-5 on both CEUS and CT/MRI with elevated carbohydrate antigen 19-9 (CA19-9); (3) LR-M on both CEUS and CT/MRI with elevated alphafetoprotein (AFP). The sensitivity, specificity, accuracy and area under the receiver operating characteristic curve (AUC) were calculated.

Results

The rates of APHE and Rim-APHE on CEUS in cHCC-CCAs were 81.5% and 9.3%, respectively. The rate of early and marked washout on CEUS in cHCC-CCAs were 59.3% and 27.8%, respectively. 64.8% and 25.9% of cHCC-CCAs showed APHE and Rim-APHE on CT/MRI, respectively. 46.3% and 35.2% of cHCC-CCAs showed washout and delay enhancement on CT/MRI, respectively. The kappa value of LI-RADS categories of cHCC-CCAs on CEUS and CT/MRI was 0.319 (P=0.008). The sensitivity, specificity, accuracy and AUC of the aforementioned diagnostic criteria for cHCC-CCAs were 64.8%, 84.4%, 76.1% and 0.746, respectively.

Conclusion

The combination of the CEUS and CT/MRI LI-RADS with serum tumor markers shows promising diagnostic performance of cHCC-CCAs.

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.

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.

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.

Diagnosis of Non-Hepatocellular Carcinoma Malignancies in Patients With Risks for Hepatocellular Carcinoma: CEUS LI-RADS Versus CT/MRI LI-RADS

Objective

Data regarding direct comparison of contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) and Computed Tomography/Magnetic Resonance Imaging (CT/MR) LI-RADS in diagnosis of non-hepatocelluar carcinoma (non-HCC) malignancies remain limited. Our study aimed to compare the diagnostic performance of the CEUS LI-RADS version 2017 and CT/MRI LI-RADS v2018 for diagnosing non-HCC malignancies in patients with risks for HCC.

Materials and Methods

In this retrospective study, 94 liver nodules pathologically-confirmed as non-HCC malignancies in 92 patients at risks for HCC from January 2009 to December 2018 were enrolled. The imaging features and the LI-RADS categories on corresponding CEUS and CT/MRI within 1 month were retrospectively analyzed according to the ACR CEUS LI-RADS v2017 and ACR CT/MRI LI-RADS v2018 by two radiologists in consensus for each algorithm. The sensitivity of LR-M category, inter-reader agreement and inter-modality agreement was compared between these two standardized algorithms.

Results

Ninety-four nodules in 92 patients (mean age, 54 years ± 10 [standard deviation] with 65 men [54 years ± 11] and 27 women [54 years ± 8]), including 56 intrahepatic cholangiocarcinomas, 34 combined hepatocellular cholangiocarcinomas, two adenosquamous carcinomas of the liver, one primary hepatic neuroendocrine carcinoma and one hepatic undifferentiated sarcoma were included. On CEUS, numbers of lesions classified as LR-3, LR-4, LR-5 and LR-M were 0, 1, 10 and 83, and on CT/MRI, the corresponding numbers were 3, 0, 14 and 77. There was no significant difference in the sensitivity of LR-M between these two standardized algorithms (88.3% of CEUS vs 81.9% of CT/MRI, p = 0.210). Seventy-seven lesions (81.9%) were classified as the same LI-RADS categories by both standardized algorithms (five for LR-5 and 72 for LR-M, kappa value = 0.307). In the subgroup analysis for ICC and CHC, no significant differences were found in the sensitivity of LR-M category between these two standardized algorithms (for ICC, 94.6% of CEUS vs 89.3% of CT/MRI, p = 0.375; for CHC, 76.5% of CEUS vs 70.6% of CT/MRI, p = 0. 649).

Conclusion

CEUS LI-RADS v2017 and CT/MRI LI-RADS v2018 showed similar value for diagnosing non-HCC primary hepatic malignancies in patients with risks.

A novel mono-modality fusion imaging method based on three-dimensional contrast-enhanced ultrasound for the evaluation of ablation margins after microwave ablation of hepatocellular carcinoma

Background

To investigate the feasibility and accuracy of using preoperative and postoperative three-dimensional contrast-enhanced ultrasound (3D CEUS) fusion imaging in the evaluation of safety margins after thermal ablation of hepatocellular carcinoma (HCC).

Methods

A total of the 24 patients with HCC who underwent microwave ablation (MWA) between June 2020 and December 2020 were enrolled in this study. All patients received preoperative and postoperative 3D CEUS. The preoperative and postoperative 3D CEUS images were then fused. The success rate and evaluation time were recorded. The ablation margin and whether or not the safety margin was reached were calculated and recorded. If the ablation safety margin was not reached, the residual ablation volume needed to cover the safety margin was calculated automatically. The agreement between contrast-enhanced computed tomography(CECT) and 3D CEUS fusion imaging in the evaluation of ablation margins was explored using the kappa coefficient.

Results

The 3D CEUS fusion success rate was 95.8% (23/24), with a mean fusion time of (4.1±1.8) minutes. Twenty-three tumors were completely ablated, and the safety margin was achieved for 9 tumors. The ablation margin of 14 tumors was <5 mm. The mean uncovered safety margin volume was (2.27±2.11) mL, and the mean proportion of the uncovered safety margin to the whole safety margin was 16.8%. According to the results of preoperative and postoperative CECT fusion imaging, the ablation margin of 13 tumors was <5 mm, and the ablation margin of 10 tumors was >5 mm. The 2 methods showed excellent consistency, with a Kappa value of 0.911 (P=0.000012).

Conclusions

This study has presented a novel mono-modality fusion imaging method based on CEUS. We demonstrated that 3D CEUS fusion has a short fusion time and a high success rate, as well as good consistency with enhanced CT fusion. Therefore, 3D CEUS fusion is a feasible and accurate tool for evaluating the immediate efficacy of thermal ablation of HCC.