Sonazoid-enhanced ultrasonography: comparison with CT/MRI Liver Imaging Reporting and Data System in patients with suspected hepatocellular carcinoma

Value of Sonazoid-enhanced ultrasonography in characterizing indeterminate focal liver lesions on gadoxetic acid-enhanced liver MRI in patients without risk factors for hepatocellular carcinoma

PURPOSE

To evaluate the added value of contrast-enhanced ultrasonography (CEUS) using Sonazoid in characterizing focal liver lesions (FLLs) with indeterminate findings on gadoxetic acid-enhanced liver MRI in patients without risk factors for hepatocellular carcinoma (HCC).

METHODS

Patients who underwent CEUS using Sonazoid for characterizing indeterminate FLLs on gadoxetic acid-enhanced liver MRI were. The indeterminate FLLs were classified according to the degree of malignancy on a 5-point scale on MRI and combined MRI and CEUS. The final diagnosis was made either pathologically or based on more than one-year follow-up. The diagnostic performance was assessed using a receiver operating characteristic (ROC) curve analysis, and the net reclassification improvement (NRI) was calculated.

RESULTS

A total of 97 patients (mean age, 49 years ± 16, 41 men, 80 benign and 17 malignant lesions) were included. When CEUS was added to MRI, the area under the ROC curve increased, but the difference was not statistically significant (0.87 [95% confidence interval {CI}, 0.77-0.98] for MRI vs 0.93 [95% CI, 0.87-0.99] for CEUS added to MRI, P = 0.296). The overall NRI was 0.473 (95% CI, 0.100-0.845; P = 0.013): 33.8% (27/80) of benign lesions and 41.2% (7/17) of malignant lesions were appropriately reclassified, whereas 10.0% (8/80) of benign lesions and 17.6% (3/17) of malignant lesions were incorrectly reclassified.

CONCLUSIONS

Although performing CEUS with Sonazoid did not significantly improve the overall diagnostic performance in characterizing indeterminate FLLs on gadoxetic acid-enhanced liver MRI in patients without risk factors for HCC, it may increase radiologist's confidence in classifying FLLs.

Intra-individual comparison of Sonazoid contrast-enhanced ultrasound and SonoVue contrast-enhanced ultrasound in diagnosing hepatocellular carcinoma

PURPOSE

To assess whether the diagnostic performance of Sonazoid contrast-enhanced ultrasound (SZUS) is non-inferior to that of SonoVue contrast-enhanced ultrasound (SVUS) in diagnosing hepatocellular carcinoma (HCC) in individuals with high risk.

MATERIALS AND METHODS

This prospective study was conducted from October 2020 to May 2022 and included participants with a high risk of HCC who underwent SZUS and SVUS. All lesions were confirmed by clinical or pathological diagnosis. Each nodule was classified according to the Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System version 2017 (CEUS LI-RADS v2017) for SVUS and SZUS and the modified CEUS LI-RADS (using Kupffer phase defect instead of late and mild washout) for SZUS. The diagnostic performance of both two modalities for all observations was compared. Analysis of the vascular phase and Kupffer phase imaging characteristics of CEUS was performed.

RESULTS

One hundred and fifteen focal liver lesions from 113 patients (94 HCCs, 12 non-HCC malignancies, and 9 benign lesions) were analysed. According to CEUS LI-RADS (v2017), SVUS and SZUS showed similar sensitivity (71.3% vs. 72.3%) and specificity (85.7% vs. 81.0%) in HCC diagnosis. However, the modified CEUS LI-RADS did not significantly improve the diagnostic efficacy of Sonazoid compared to CEUS LI-RADS v2017, having equivalent sensitivity (73.4% vs. 72.3%) and specificity (81.0% vs. 81.0%). The agreement between SVUS and SZUS for all observations was 0.610 (95% CI 0.475, 0.745), while for HCCs it was 0.452 (95% CI 0.257, 0.647).

CONCLUSION

Using LI-RADS v2017, SZUS and SVUS showed non-inferior efficacy in evaluating HCC lesions. In addition, adding Kupffer phase defects to SZUS does not notably improve its diagnostic efficacy.

The efficacy of modified contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) using Sonazoid in diagnosis of hepatocellular carcinoma: a systematic review and meta-analysis

Background

The contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) is an algorithm for the diagnosis of hepatocellular carcinoma (HCC) in high-risk populations. Previous studies have shown the algorithm to have high specificity and moderate sensitivity. Nevertheless, it is designated for utilization solely with blood pool contrast agents. Sonazoid, a contrast agent that combines blood pools and Kupffer cells properties, has recently gained approval for marketing in an increased number of countries. Enhanced sensitivity in diagnosing HCC may be achieved through the distinctive Kupffer phase (KP) exhibited by Sonazoid. Certain academics have suggested the modified CEUS LI-RADS using Sonazoid. The main criteria of mild and late (≥60 seconds) washout in CEUS LI-RADS LR-5 were replaced by KP (>10 minutes) defects as the primary criteria. The purpose of this research was to evaluate the effectiveness of the modified CEUS LI-RADS using Sonazoid in diagnosing HCC.

Methods

Original studies on Sonazoid and CEUS LI-RADS were searched in the PubMed, Embase, Cochrane Library, and Web of Science databases until 13 July 2023, with no restrictions on language. We enrolled studies that applied Sonazoid for CEUS in patients at high risk of HCC and modified CEUS LI-RADS for the diagnosis of intrahepatic nodules. Meta-analyses, evaluations, case studies, correspondences, remarks, and summaries of conferences were excluded. Additionally, studies that fell outside the scope of this study and contained data on the same patients were also excluded. We evaluated the quality of research by employing the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. A bivariate mixed effects model was utilized to conduct a meta-analysis, summarizing the sensitivity and specificity in the diagnosis of HCC. The investigation of potential factors contributing to study heterogeneity was conducted using meta-regression analysis.

Results

Out of the 103 studies screened, 6 studies (835 lesions) were included in the final results. Modified CEUS LR-5 exhibited a sensitivity of 0.77 [95% confidence interval (CI): 0.70-0.82; I2=71.98%; P=0.00] and a specificity of 0.88 (95% CI: 0.83-0.92; I2=0.00; P=0.47) for HCC diagnosis, with heterogeneity in sensitivity. The presence of heterogeneity in the study was found to have a significant association with factors such as the study design, the number of image reviewers, the proportion of cirrhosis, the proportion of other non-HCC malignancies (OM) cases, and the type of reference standard (P≤0.05).

Conclusions

The modified CEUS LI-RADS LR-5 categorization demonstrates a reasonable level of sensitivity 0.77, but an insufficient level of specificity 0.88 when diagnosing HCC. KP defects cannot be used as a primary feature in the diagnosis of HCC by CEUS LI-RADS, perhaps as an ancillary feature.

Compared with SonoVue® LR-5, Sonazoid® modified LR-5 has better diagnostic sensitivity for hepatocellular carcinoma: a systematic review and meta-analysis

Background

The contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) is a standardized system for reporting liver nodules in patients at risk of developing hepatocellular carcinoma (HCC) and is only recommended for pure blood pool agents such as SonoVue®. A modified LI-RADS was proposed for Sonazoid®, a Kupffer cell-specific contrast agent. This meta-analysis was conducted to compare the diagnostic efficiency of the CEUS LI-RADS for SonoVue® and the modified LI-RADS for Sonazoid®.

Methods

The PubMed, Medline, Web of Science, Embase, and Cochrane Library databases were systematically searched to retrieve studies on the diagnostic efficiency of the CEUS LI-RADS algorithms in diagnosing HCC using SonoVue® and/or Sonazoid® from January 2016 to June 2023. Histopathology or imaging follow-up served as the reference standards. Only articles published in English on retrospective or prospective studies with full reports were included in the meta-analysis. A bivariate random-effects model was used. Data pooling, meta-regression, and sensitivity analysis were performed for the meta-analysis. Deeks' funnel plot asymmetry test was used to evaluate publication bias, and the QUADAS-2 tool was used to assess the methodological quality of eligible studies.

Results

In total, 26 studies comprising 8,495 patients with 9,244 lesions were included in the meta-analysis. The pooled data results for SonoVue® LI-RADS category 5 (LR-5) and Sonazoid® modified LR-5 were as follows: pooled sensitivity: 0.68 [95% confidence interval (CI): 0.64-0.73, I2=89.20%; P<0.01] and 0.82 (95% CI: 0.74-0.87, I2=85.39%; P<0.01) (P<0.05); pooled specificity: 0.93 (95% CI: 0.90-0.96, I2=86.52%; P<0.01) and 0.86 (95% CI: 0.79-0.91, I2=59.91%; P=0.01) (P<0.05); pooled area under the curve (AUC): 0.86 (95% CI: 0.82-0.89) and 0.91 (95% CI: 0.88-0.93) (P<0.05), respectively. The meta-regression analysis revealed that the study design, subject enrollment method, and reference standard contributed to the heterogeneity of SonoVue® LR-5, and the number of lesions was a source of heterogeneity for Sonazoid® modified LR-5. The diagnostic performance of the LI-RADS category M (LR-M) algorithms of SonoVue® and Sonazoid® was comparable.

Conclusions

The Sonazoid® modified LR-5 algorithm had a higher diagnostic sensitivity, lower specificity, and higher AUC than SonoVue® LR-5.

Contrast-Enhanced Ultrasound With Perfluorobutane for Hepatocellular Carcinoma Diagnosis: Comparison of Imaging Phases and Diagnostic Criteria

BACKGROUND. Contrast-enhanced ultrasound (CEUS) with perfluorobutane has used varying protocols and diagnostic criteria for hepatocellular carcinoma (HCC). OBJECTIVE. The purpose of this article was to assess diagnostic performance for HCC of CEUS with perfluorobutane in high-risk patients using various criteria. METHODS. This retrospective post hoc study evaluating individual patient data from three earlier prospective studies from one hospital included 204 patients (136 men, 68 women; mean age, 63 ± 11 [SD] years) at high risk of HCC with 213 liver observations. Patients underwent CEUS using perfluorobutane from March 2019 to June 2022. Three radiologists (the examination's operator and two subsequent reviewers) independently interpreted examinations, assessing arterial, portal venous (arterial phase completion through 2 minutes), transitional (2-5 minutes after injection), and Kupffer (≥ 10 minutes after injection) phase findings. Six criteria for HCC were tested: 1, any arterial phase hyperenhancement (APHE) with Kupffer phase hypoenhancement; 2, nonrim APHE with Kupffer phase hypoenhancement; 3, nonrim APHE with portal venous washout; 4, nonrim APHE with portal venous washout and/or Kupffer phase hypoenhancement; 5, nonrim APHE with portal venous and/or transitional washout; 6, nonrim APHE with any of portal venous washout, transitional washout, or Kupffer phase hypoenhancement. Depending on the criteria, observations were instead deemed to be a non-HCC malignancy if showing rim APHE, early washout (at < 1 minute), or marked washout (at 2 minutes). Reference was pathology for malignant observations and pathology or imaging follow-up for benign observations. Diagnostic performance was assessed, pooling readers' data. RESULTS. Criterion 1 (no recognized features of non-HCC malignancy) had highest sensitivity (86.9%) but lowest specificity (43.2%) for HCC. Compared with nonrim APHE and portal venous washout (criterion 3), the addition of Kupffer phase hypoenhancement (criterion 4), transitional washout (criterion 5), or either feature (criterion 6) significantly increased sensitivity (34.4% vs 62.6-64.2%) and accuracy (61.8% vs 75.1-76.5%), but significantly decreased specificity (98.5% vs 91.9-94.1%). Criteria 2, 4, 5, and 6 (all incorporating transitional washout and/or Kupffer phase hypoenhancement) showed no significant differences in sensitivity (62.6-64.2%), specificity (91.9-94.1%), or accuracy (75.1-76.5%). CONCLUSION. Recognition of features of non-HCC malignancy improved specificity for HCC. Incorporation of the findings of transitional washout and/or Kupffer phase hypoenhancement improved sensitivity and accuracy, albeit lowered specificity, versus arterial and portal venous findings alone, without further performance variation among criteria incorporating those two findings. CLINICAL IMPACT. Kupffer phase acquisition may be optional for observations classified as HCC or non-HCC malignancy by arterial, portal venous, and transitional phases.

Assessment of arterial-phase hyperenhancement and late-phase washout of hepatocellular carcinoma-a meta-analysis of contrast-enhanced ultrasound (CEUS) with SonoVue® and Sonazoid®

OBJECTIVES

The recognition of arterial phase hyperenhancement (APHE) and washout during the late phase is key for correct diagnosis of hepatocellular carcinoma (HCC) with contrast-enhanced ultrasound (CEUS). This meta-analysis was conducted to compare SonoVue®-enhanced and Sonazoid®-enhanced ultrasound in the assessment of HCC enhancement and diagnosis.

METHODS

Studies were included in the analysis if they reported data for HCC enhancement in the arterial phase and late phase for SonoVue® or in the arterial phase and Kupffer phase (KP) for Sonazoid®. Forty-two studies (7502 patients) with use of SonoVue® and 30 studies (2391 patients) with use of Sonazoid® were identified. In a pooled analysis, the comparison between SonoVue® and Sonazoid® CEUS was performed using chi-square test. An inverse variance weighted random-effect model was used to estimate proportion, sensitivity, and specificity along with 95% confidence interval (CI).

RESULTS

In the meta-analysis, the proportion of HCC showing APHE with SonoVue®, 93% (95% CI 91-95%), was significantly higher than the proportion of HCC showing APHE with Sonazoid®, 77% (71-83%) (p < 0.0001); similarly, the proportion of HCC showing washout at late phase/KP was significantly higher with SonoVue®, 86% (83-89%), than with Sonazoid®, 76% (70-82%) (p < 0.0001). The sensitivity and specificity for the detection of APHE plus late-phase/KP washout detection in HCC were also higher with SonoVue® than with Sonazoid® (sensitivity 80% vs 52%; specificity 80% vs 73% in studies within unselected patient populations).

CONCLUSION

APHE and late washout in HCC are more frequently observed with SonoVue® than with Sonazoid®. This may affect the diagnostic performance of CEUS in the diagnosis of HCCs.

CLINICAL RELEVANCE STATEMENT

Meta-analysis data show the presence of key enhancement features for diagnosis of hepatocellular carcinoma is different between ultrasound contrast agents, and arterial hyperenhancement and late washout are more frequently observed at contrast-enhanced ultrasound with SonoVue® than with Sonazoid®.

KEY POINTS

• Dynamic enhancement features are key for imaging-based diagnosis of HCC. • Arterial hyperenhancement and late washout are more often observed in HCCs using SonoVue®-enhanced US than with Sonazoid®. • The existing evidence for contrast-enhanced US may need to be considered being specific to the individual contrast agent.

Sonazoid-enhanced ultrasonography for noninvasive imaging diagnosis of hepatocellular carcinoma: special emphasis on the 2022 KLCA-NCC guideline

Contrast-enhanced ultrasonography (CEUS) is a noninvasive imaging modality used to diagnose hepatocellular carcinoma (HCC) based on specific imaging features, without the need for pathologic confirmation. Two types of ultrasound contrast agents are commercially available: pure intravascular agents (such as SonoVue) and Kupffer agents (such as Sonazoid). Major guidelines recognize CEUS as a reliable imaging method for HCC diagnosis, although they differ depending on the contrast agents used. The Korean Liver Cancer Association-National Cancer Center guideline includes CEUS with either SonoVue or Sonazoid as a second-line diagnostic technique. However, Sonazoid-enhanced ultrasound is associated with several unresolved issues. This review provides a comparative overview of these contrast agents regarding pharmacokinetic features, examination protocols, diagnostic criteria for HCC, and potential applications in the HCC diagnostic algorithm.

Perfluorobutane-Enhanced Ultrasound for Characterization of Hepatocellular Carcinoma From Non-hepatocellular Malignancies or Benignancy: Comparison of Imaging Acquisition Methods

OBJECTIVE

The aim of the work described here was to evaluate the diagnostic performance of perfluorobutane (PFB)-enhanced ultrasound in differentiating hepatocellular carcinoma (HCC) from non-HCC malignancies and other benign lesions using different acquisition methods.

METHODS

This prospective study included 69 patients with solid liver lesions larger than 1 cm who were scheduled for biopsy or radiofrequency ablation between September 2020 and March 2021. Lesion diagnosis was designated by three blinded radiologists after reviewing three different sets of acquired images selected according to the following presumed acquisition methods: (i) method A, acquisition up to 5 min after contrast injection; (ii) method B, acquisition up to 1 min after contrast injection with additional Kupffer phase; and (iii) method C, acquisition up to 5 min after contrast injection with additional Kupffer phase.

RESULTS

After excluding 7 technical failures, 62 patients with liver lesions (mean size: 24.2 ± 14.8 mm), which consisted of 7 benign lesions, 37 non-HCC malignancies and 18 HCCs. For the HCC diagnosis, method C had the highest sensitivity (75.9%), followed by method B (72.2%) and method A (68.5%), but failed to exhibit statistical significance (p = 0.12). There was no significant difference with respect to the pooled specificity between the three methods (p = 0.28). Diagnostic accuracy was the highest with method C (87.1%) but failed to exhibit statistical significance (p = 0.24).

CONCLUSION

Image acquisition up to 5 min after contrast injection with additional Kupffer phase could potentially result in high accuracy and sensitivity without loss of specificity in diagnosing HCC with PFB-enhanced ultrasound.

Diagnosis of hepatocellular carcinoma using Sonazoid: a comprehensive review

Sonazoid contrast-enhanced ultrasonography (CEUS) is a promising technique for the detection and diagnosis of focal liver lesions, particularly hepatocellular carcinoma (HCC). Recently, a collaborative effort between the Korean Society of Radiology and Korean Society of Abdominal Radiology resulted in the publication of guidelines for diagnosing HCC using Sonazoid CEUS. These guidelines propose specific criteria for identifying HCC based on the imaging characteristics observed during Sonazoid CEUS. The suggested diagnostic criteria include nonrim arterial phase hyperenhancement, and the presence of late and mild washout, or Kupffer phase washout under the premise that the early or marked washout should not occur during the portal venous phase. These criteria aim to improve the accuracy of HCC diagnosis using Sonazoid CEUS. This review offers a comprehensive overview of Sonazoid CEUS in the context of HCC diagnosis. It covers the fundamental principles of Sonazoid CEUS and its clinical applications, and introduces the recently published guidelines. By providing a summary of this emerging technique, this review contributes to a better understanding of the potential role of Sonazoid CEUS for diagnosing HCC.

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.

Compared with CT/MRI LI-RADS, whether CEUS LI-RADS is worth popularizing in diagnosis of hepatocellular carcinoma?-a direct head-to-head meta-analysis

Background

Until now, there has been no systematic review or meta-analysis of direct head-to-head studies that compare two liver imaging reporting and data system (LI-RADS) algorithms, contrast-enhanced ultrasound (CEUS) LI-RADS and contrast-enhanced computed tomography/magnetic resonance imaging (CT/MRI) LI-RADS, for the diagnostic efficacy of hepatocellular carcinoma. The purpose of this study was to identify and head-to-head compare the diagnostic performance of both LI-RADS algorithms for hepatocellular carcinoma.

Methods

We searched the PubMed, EMBASE, Web of Science, and Cochrane Library databases from the inception of each database to April 26, 2022, to find the comparative study of both LI-RADS algorithms for hepatocellular carcinoma at risk of patients who underwent both LI-RADS algorithms. Eligibility criteria included only studies published in English, full reports published, both retrospective and prospective studies. Liver histology or imaging follow-up results served as the reference standard. We analyzed the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and summary receiver operating characteristic curve to determine summary estimates. The Quality Assessment of Diagnostic Accuracy Studies was utilized to assess the methodological quality.

Results

In 5 included studies (831 patients, 877 lesions), the pooled sensitivity and pooled specificity of CEUS LR-5 were 0.79, 0.81, and 0.78, 0.79 in CT/MRI LR-5, respectively. The pooled sensitivity and pooled specificity of CEUS LR-4/5 were 0.86, 0.70, and 0.93, 0.59 in CT/MRI LR-4/5, respectively. There was no obvious difference between the two LI-RADS algorithms for hepatocellular carcinoma, and there was no significant statistical difference between two LR-M algorithms for non-hepatocellular carcinoma malignancies.

Conclusions

The results of our analysis demonstrated that CEUS LI-RADS has satisfactory diagnostic performance similar to that of CT/MRI LI-RADS, which provides a theoretical basis for the popularization of CEUS LI-RADS for diagnosing HCC. This work was supported by Sichuan Science and Technology Program (No. 2020YFS0211). We registered this study on the international prospective register of systematic reviews (PROSPERO, CRD42022328107) before the search step.

Diagnosing Hepatocellular Carcinoma Using Sonazoid Contrast-Enhanced Ultrasonography: 2023 Guidelines From the Korean Society of Radiology and the Korean Society of Abdominal Radiology

Sonazoid, a second-generation ultrasound contrast agent, was introduced for the diagnosis of hepatic nodules. To clarify the issues with Sonazoid contrast-enhanced ultrasonography for the diagnosis of hepatocellular carcinoma (HCC), the Korean Society of Radiology and Korean Society of Abdominal Radiology collaborated on the guidelines. The guidelines are de novo, evidence-based, and selected using an electronic voting system for consensus. These include imaging protocols, diagnostic criteria for HCC, diagnostic value for lesions that are inconclusive on other imaging results, differentiation from non-HCC malignancies, surveillance of HCC, and treatment response after locoregional and systemic treatment for HCC.

Head-to-head comparison of Sonazoid and SonoVue in the diagnosis of hepatocellular carcinoma for patients at high risk

Objectives

To compare the diagnostic efficacy of SonoVue-enhanced and Sonazoid-enhanced ultrasound (US) for hepatocellular carcinoma (HCC) in patients at high risk.

Methods

Between August 2021 and February 2022, participants at high risk for HCC with focal liver lesions were enrolled and underwent both SonoVue- and Sonazoid-enhanced US. Vascular-phase and Kupffer phase (KP) imaging features of contrast-enhanced US (CEUS) were analyzed. The diagnostic performance of both contrast agent-enhanced US according to the CEUS liver imaging reporting and data system (LI-RADS) and the modified criteria (using KP defect instead of late and mild washout) were compared. Histopathology and contrast-enhanced MRI/CT were used as reference standards.

Results

In total, 62 nodules, namely, 55 HCCs, 3 non-HCC malignancies and 4 hemangiomas, from 59 participants were included. SonoVue-enhanced US had comparable sensitivity to Sonazoid-enhanced US for diagnosing HCC [80% (95% confidential interval (CI): 67%, 89.6%) versus 74.6% (95% CI: 61%, 85.3%), p = 0.25]. Both SonoVue and Sonazoid-enhanced US achieved a specificity of 100%. Compared with CEUS LI-RADS, the modified criteria with Sonazoid did not improve sensitivity for HCC diagnosis [74.6% (95% CI: 61%, 85.3%) versus 76.4% (95% CI: 63%, 86.8%), p = 0.99].

Conclusions

Sonazoid-enhanced US had comparable diagnostic performance to SonoVue-enhanced US for patients with HCC risk. KP did not considerably improve the diagnostic efficacy, whereas KP defects in atypical hemangioma may be pitfalls in diagnosing HCC. Further studies with larger sample sizes are needed to further validate the conclusions in the present study.

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.

Sonazoid™ versus SonoVue® for Diagnosing Hepatocellular Carcinoma Using Contrast-Enhanced Ultrasound in At-Risk Individuals: A Prospective, Single-Center, Intraindividual, Noninferiority Study

OBJECTIVE

To determine whether Sonazoid-enhanced ultrasound (SZUS) was noninferior to SonoVue-enhanced ultrasound (SVUS) in diagnosing hepatocellular carcinoma (HCC) using the same diagnostic criteria.

MATERIALS AND METHODS

This prospective, single-center, noninferiority study (NCT04847726) enrolled 105 at-risk participants (71 male; mean age ± standard deviation, 63 ± 11 years; range, 26-86 years) with treatment-naïve solid hepatic nodules (≥ 1 cm). All participants underwent same-day SZUS (experimental method) and SVUS (control method) for one representative nodule per participant. Images were interpreted by three readers (the operator and two independent readers). All malignancies were diagnosed histopathologically, while the benignity of other lesions was confirmed by follow-up stability or pathology. The primary endpoint was per-lesion diagnostic accuracy for HCC pooled across three readers using the conventional contrast-enhanced ultrasound diagnostic criteria, including arterial phase hyperenhancement followed by mild (assessed within 2 minutes after contrast injection) and late (≥ 60 seconds with a delay of 5 minutes) washout. The noninferiority delta was -10%p. Furthermore, different time delays were compared as washout criteria in SZUS, including delays of 2, 5, and > 10 minutes.

RESULTS

A total of 105 lesions (HCCs [n = 61], non-HCC malignancies [n = 19], and benign [n = 25]) were evaluated. Using the 5-minutes washout criterion, per-lesion accuracy of SZUS pooled across the three readers (72.4%; 95% confidence interval [CI], 64.1%-79.3%) was noninferior to that of SVUS (71.4%; 95% CI, 63.1%-78.6%), meeting the statistical criterion for non-inferiority (difference of 0.95%p; 95% CI, -3.8%p-5.7%p). The arterial phase hyperenhancement combined with the 5-minutes washout criterion showed the same sensitivity as that of the > 10-minutes criterion (59.0% vs. 59.0%, p = 0.989), and the specificities were not significantly different (90.9% vs. 86.4%, p = 0.072).

CONCLUSION

SZUS was noninferior to SVUS for diagnosing HCC in at-risk patients using the same diagnostic criteria. No significant improvement in HCC diagnosis was observed by extending the washout time delay from 5 to 10 minutes.

Imaging Features of Hepatocellular Carcinoma in the Non-Cirrhotic Liver with Sonazoid-Enhanced Contrast-Enhanced Ultrasound

Purpose: To investigate the Sonazoid-enhanced contrast-enhanced ultrasound (CEUS) features of hepatocellular carcinoma (HCC) in a non-cirrhosis liver background, in comparison to those in liver cirrhosis. Methods: In this retrospective study, 19 patients with surgery and histopathologically proven HCC lesions in non-cirrhosis liver background were included regarding Sonazoid-enhanced CEUS characteristics. Two radiologists evaluated the CEUS features of HCC lesions according to the WFUMB (World Federation of Societies for Ultrasound in Medicine and Biology) guidelines criteria. Thirty-six patients with HCC lesions in liver cirrhosis were included as a control group. Final diagnoses were confirmed by surgery and histopathological results. Results: Liver background of the non-cirrhosis group including normal liver (n = 7), liver fibrosis (n = 11), and alcoholic liver disease (n = 1). The mean size of non-cirrhosis HCC lesions was 60.8 ± 46.8 mm (ranging from 25 to 219 mm). During the arterial phase of Sonazoid-enhanced CEUS, most HCCs in non-cirrhotic liver (94.7%, 18/19) and in cirrhotic liver (83.3%, 30/36) presented non-rim hyperenhancement. During the portal venous phase, HCC lesions in the non-cirrhosis liver group showed relatively early washout (68.4%, 13/19) (p = 0.090). Meanwhile, HCC lesions in liver cirrhosis background showed isoenhancement (55.6%, 20/36). All lesions in the non-cirrhotic liver group showed hypoenhancement in the late phase and the Kupffer phase (100%, 19/19). Five cases of HCC lesions in liver cirrhosis showed isoenhancement during the late phase and hypoenhancement during the Kupffer phase (13.9%, 5/36). The rest of the cirrhotic HCC lesions showed hypoenhancement during the late phase and the Kupffer phase (86.1%, 31/36). Additional hypoenhanced lesions were detected in three patients in the non-cirrhosis liver group and eight patients in the liver cirrhosis group (mean size: 13.0 ± 5.6 mm), which were also suspected to be HCC lesions. Conclusions: Heterogeneous hyperenhancement during the arterial phase as well as relatively early washout are characteristic features of HCC in the non-cirrhotic liver on Sonazoid-enhanced CEUS.

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 Using Perfluorobutane: Impact of Proposed Modified LI-RADS Criteria on Hepatocellular Carcinoma Detection

BACKGROUND. Contrast-enhanced ultrasound (CEUS) LI-RADS version 2017 (v2017) applies only to CEUS examinations performed using pure blood pool agents, noting that future versions will address combined blood pool and Kupffer cell agents such as perfluorobutane. Such agents may improve hepatocellular carcinoma (HCC) detection by visualization of a defect in the Kupffer phase (obtained ≥ 10 minutes after injection). OBJECTIVE. The purpose of our study was to compare the diagnostic performance of the LR-5 category for HCC detection in at-risk patients between CEUS LI-RADS v2017 and proposed modified criteria for CEUS examinations performed using perfluorobutane. METHODS. This retrospective study included 293 patients at risk for HCC (259 men, 34 women; mean age, 55 ± 12 [SD] years) who underwent CEUS using perfluorobutane from March 1, 2020, to October 30, 2020, showing a total of 304 observations (274 HCC, 14 non-HCC malignancy, and 16 benign lesions). Two readers independently assessed examinations and assigned categories using both CEUS LI-RADS v2017 and the proposed modified criteria. In the modified criteria, observations 10 mm or greater with not rim arterial phase hyperenhancement (APHE), no washout, and a Kupffer defect were upgraded from LR-4 to LR-5, and observations 10 mm or greater with not rim APHE, early washout, and a mild Kupffer defect were reassigned from LR-M to LR-5. Interreader agreement was assessed, and consensus interpretations were reached. Diagnostic performance was evaluated. RESULTS. Interreader agreement for LI-RADS category assignments, expressed using kappa coefficients, was 0.839 for CEUS LI-RADS v2017 and 0.854 for the modified criteria. Modified criteria upgraded 35 observations from LR-4 to LR-5 on the basis of a Kupffer defect, of which 34 were HCC and one was benign. Modified criteria reassigned 22 observations from LR-M to LR-5 on the basis of a mild Kupffer defect, of which all were HCC. LR-5 using modified criteria, compared with CEUS LI-RADS v2017, had significantly increased sensitivity (89% vs 69%, p < .001), a nonsignificant decrease in specificity (83% vs 87%, p > .99), and significantly increased accuracy (89% vs 71%, p < .001) for HCC. CONCLUSION. When using perfluorobutane for CEUS in at-risk patients, modified criteria incorporating Kupffer defects significantly improve sensitivity without significant loss of specificity in HCC detection. CLINICAL IMPACT. Future CEUS LI-RADS updates seeking to address the use of combined blood pool and Kupffer cell agents should consider adoption of the explored criteria.

Comparison of modified CEUS LI-RADS with sonazoid and CT/MRI LI-RADS for diagnosis of hepatocellular carcinoma

AIM

To compare the diagnostic performance based on the modified CEUS Liver Imaging Reporting and Data System (LI-RADS), which includes Kupffer-phase findings as a major imaging feature, with that of CT and MRI (CT/MRI) LI-RADS for liver nodules in patients at high risk of HCC.

METHODS

A total of 120 patients with 120 nodules were included in this retrospective study. The median size of the lesions was 20.0 mm (interquartile range, 14.0-30.8 mm). Of these lesions, 90.0% (108 of 120) were confirmed as HCCs, 6.7% (8 of 120) were intrahepatic cholangiocarcinomas, 1.7% (2 of 120) were metastases, and 1.7% (2 of 120) were dysplastic nodules. All nodules were diagnosed histopathologically. Each nodule was categorized according to the modified CEUS LI-RADS and CT/MRI LI-RADS version 2018. The diagnostic performance and inter-modality agreement of each criterion was compared.

RESULTS

The inter-modality agreement for the modified CEUS LI-RADS and CT/MRI LI-RADS was slight agreement (kappa = 0.139, p = 0.015). The diagnostic accuracies of HCCs for the modified CEUS LR-5 and CT/MRI LR-5 were 70.0% (95% confidence interval [CI]: 61.0%, 78.0%) versus 70.8% (95% CI: 61.8%, 78.8%) (p = 0.876), respectively. The diagnostic accuracies of non-HCC malignancies for the modified CEUS LR-M and CT/MRI LR-M were 84.2% (95% CI: 76.4%, 90.2%) versus 96.7% (95% CI: 91.7%, 99.1%) (p = 0.002), respectively.

CONCLUSIONS

The diagnostic performance for HCCs on the modified CEUS LR-5 and CT/MRI LR-5 are comparable. In contrast, CT/MRI LR-M has better diagnostic performance for non-HCC malignancy than that of the modified CEUS LR-M.

Perfluorobutane-enhanced ultrasonography with a Kupffer phase: improved diagnostic sensitivity for hepatocellular carcinoma

OBJECTIVES

To evaluate the diagnostic accuracy of perfluorobutane contrast-enhanced ultrasonography (CEUS) for hepatocellular carcinoma (HCC) and to explore how accuracy can be improved compared to conventional diagnostic criteria in at-risk patients.

METHODS

A total of 123 hepatic nodules (≥ 1 cm) from 123 at-risk patients who underwent perfluorobutane CEUS between 2013 and 2020 at three institutions were retrospectively analyzed. Ninety-three percent of subjects had pathological results, except benign lesions stable in follow-up images. We evaluated presence of arterial phase hyperenhancement (APHE), washout time and degree, and Kupffer phase (KP) defects. KP defects are defined as hypoenhancing lesions relative to the liver in KP. HCC was diagnosed in two ways: (1) Liver Imaging Reporting and Data System (LI-RADS) criteria defined as APHE and late (≥ 60 s)/mild washout, and (2) APHE and Kupffer (AK) criteria defined as APHE and KP defect. We explored grayscale features that cause misdiagnosis of HCC and reflected in the adjustment. Diagnostic performance was compared using McNemar's test.

RESULTS

There were 77 HCCs, 15 non-HCC malignancies, and 31 benign lesions. An ill-defined margin without hypoechoic halo on grayscale applied as a finding that did not suggest HCC. Regarding diagnosis of HCC, sensitivity of AK criteria (83.1%; 95% confidence interval [CI]: 72.9-90.7%) was higher than that of LI-RADS criteria (75.3%; 95% CI: 64.2-84.4%; p = 0.041). Specificity was 91.3% (95% CI: 79.2-97.6%) in both groups.

CONCLUSION

On perfluorobutane CEUS, diagnostic criteria for HCC using KP defect with adjustment by grayscale findings had higher diagnostic performance than conventional criteria without losing specificity.

KEY POINTS

• Applying Kupffer phase defect instead of late/mild washout and adjusting with grayscale findings can improve the diagnostic performance of perfluorobutane-enhanced US for HCC. • Adjustment with ill-defined margins without a hypoechoic halo for features unlikely to be HCC decreases false positives for HCC diagnosis using the perfluorobutane-enhanced US. • After adjustment with grayscale findings, the sensitivity and accuracy of the APHE and Kupffer criteria were higher than those of the LI-RADS criteria; specificity was 91.3% for both.

Second-line Sonazoid-enhanced ultrasonography for Liver Imaging Reporting and Data System category 3 and 4 on gadoxetate-enhanced magnetic resonance imaging

Purpose

This study investigated the utility of second-line contrast-enhanced ultrasonography (CEUS) using Sonazoid in Liver Imaging Reporting and Data System category 3 (LR-3) and 4 (LR-4) observations on gadoxetate-enhanced magnetic resonance imaging (MRI).

Methods

This retrospective study included LR-3 or LR-4 observations on gadoxetate-enhanced MRI subsequently evaluated with CEUS from 2013 to 2017. The presence of MRI features, CEUS-arterial phase hyperenhancement (CEUS-APHE), and Kupffer phase defect (KPD) was evaluated. Multivariable logistic regression analysis was performed to identify significant imaging features associated with the diagnosis of hepatocellular carcinoma (HCC). The optimal diagnostic criteria were investigated using the McNemar test.

Results

In total, 104 patients with 104 observations (63 HCCs) were included. The presence of both CEUS-APHE and KPD on CEUS enabled the additional detection of 42.3% (11/26) of LR-3 HCCs and 78.4% (29/37) of LR-4 HCCs. Transitional phase (TP) hypointensity (adjusted odds ratio [OR], 10.59; P<0.001), restricted diffusion (adjusted OR, 7.55; P=0.004), and KPD (adjusted OR, 7.16; P=0.003) were significant imaging features for HCC diagnosis. The presence of at least two significant imaging features was optimal for HCC diagnosis (sensitivity, specificity, and accuracy: 88.9%, 78.1%, and 84.6%, respectively), with significantly higher sensitivity than the presence of both CEUS-APHE and KPD (sensitivity, specificity, and accuracy: 63.5% [P=0.001], 92.7% [P=0.077], and 75.0% [P=0.089], respectively).

Conclusion

The combined interpretation of gadoxetate-enhanced MRI and second-line CEUS using Sonazoid, focusing on TP hypointensity, restricted diffusion, and KPD, may be optimal for further characterizing LR-3 and LR-4 observations.

Diagnostic criteria of perfluorobutane-enhanced ultrasonography for diagnosing hepatocellular carcinoma in high-risk individuals: how is late washout determined?

PURPOSE

The aim of this study was to investigate the optimal washout criteria of perfluorobutane-enhanced ultrasonography (PFB-US) for the diagnosis of hepatocellular carcinoma (HCC) in high-risk individuals.

METHODS

Participants at risk of HCC with treatment-naïve solid hepatic observations (≥1 cm) who underwent PFB-US from March 2019 to September 2020 were prospectively recruited. Arterial phase hyperenhancement (APHE), washout time, and washout degree were evaluated. The diagnosis of HCC was made by non-rim APHE with late and mild washout. The per-lesion diagnostic performance for diagnosing HCC using different cutoffs for late washout (50, 55, 60, 65, and 70 seconds postcontrast) and the different time windows for determining washout (until 2, 3, 4, 5, 6, 7, 8, 9, and 10 minutes postcontrast) were compared using the McNemar test.

RESULTS

In total, 101 participants with 113 observations (mean size, 33.5±2.8 mm; HCCs [n=82], non-HCC malignancies [n=16], benign [n=15]) were evaluated. Non-rim APHE was observed in 86.6% (71/82) of HCCs. As the cutoff time for late washout increased, the specificity increased to 100% (95% confidence interval [CI], 88.8% to 100%) at the 60-second cutoff with 62.2% sensitivity (95% CI, 50.8% to 72.7%). When the time window for determining washout became wider, the sensitivity and accuracy increased until 6 minutes, with 100% specificity at all times.

CONCLUSION

Determining washout within 6 minutes after contrast injection with a 60-second cutoff for late washout showed the highest sensitivity without losing specificity for diagnosing HCC using PFB-US in individuals at high risk.