Can contrast enhanced ultrasound differentiate intrahepatic cholangiocarcinoma from hepatocellular carcinoma?

Rare infiltrative primary hepatic angiosarcoma: A case report and review of literature

BACKGROUND

The most primary sites of angiosarcoma are the skin, breast gland, and soft tissues. Primary hepatic angiosarcoma (PHA) is a rare malignant tumor of mesothelial tissue originating from the liver. PHA often presents with multiple intrahepatic foci or metastasis at the time of presentation due to its nonspecific clinical presentation and highly aggressive nature. There are no established or effective treatment guidelines for PHA, so early detection and early treatment are of great value for patient survival. Unfortunately, there is a paucity of literature on the imaging features of PHA, making the diagnosis and treatment of this disease a considerable challenge.

CASE SUMMARY

In this case report, we present a 59-year-old man who initially presented with abdominal pain and radiating pain in the right shoulder. Magnetic resonance imaging and positron emission tomography-computed tomography revealed multiple intrahepatic nodules that needed to be differentiated from tumors of vascular epithelial origin and tumors with progressive enhancement features, and signs of tumor metastasis were assessed. The patient was then subjected to contrast-enhanced ultrasonography (CEUS) to further clarify the extent of tumor infiltration and the state of microcirculatory perfusion. The manifestations observed on CEUS were similar to the classical characteristic presentation of hepatocellular carcinoma, called "quick wash-in and quick wash-out". In addition, CEUS showed that the lesion exhibited gradual infiltration and growth along the liver pedicle structures with no invading blood vessels. Finally, based on pathological and immunohistochemical tests and the above imaging manifestations, it was confirmed that the patient had infiltrating PHA, which is a rare pathological type of PHA. The patient underwent transcatheter arterial chemoembolization and chemotherapy. Four months after the onset of symptoms, the follow-up radiological examination revealed poor treatment efficacy and rapid deterioration.

CONCLUSION

This case report complements the imaging modalities of a rare infiltrative PHA, in which CEUS and quantitative analysis are found to offer substantial advantages in characterizing the microcirculatory perfusion of the lesion, providing clinicians with diagnostic information at the earliest opportunity to make a diagnosis and develop a treatment strategy to prolong the patient survival.

A multi-parameter intrahepatic cholangiocarcinoma scoring system based on modified contrast-enhanced ultrasound LI-RADS M criteria for differentiating intrahepatic cholangiocarcinoma from hepatocellular carcinoma

PURPOSE

To develop a multi-parameter intrahepatic cholangiocarcinoma (ICC) scoring system and compare its diagnostic performance with contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system M (LR-M) criteria for differentiating ICC from hepatocellular carcinoma (HCC).

METHODS

This retrospective study enrolled 62 high-risk patients with ICCs and 62 high-risk patients with matched HCCs between January 2022 and December 2022 from two institutions. The CEUS LR-M criteria was modified by adjusting the early wash-out onset (within 45 s) and the marked wash-out (within 3 min). Then, a multi-parameter ICC scoring system was established based on clinical features, B-mode ultrasound features, and modified LR-M criteria.

RESULT

We found that elevated CA 19-9 (OR=12.647), lesion boundary (OR=11.601), peripheral rim-like arterial phase hyperenhancement (OR=23.654), early wash-out onset (OR=7.211), and marked wash-out (OR=19.605) were positive predictors of ICC, whereas elevated alpha-fetoprotein (OR=0.078) was a negative predictor. Based on these findings, an ICC scoring system was established. Compared with the modified LR-M and LR-M criteria, the ICC scoring system showed the highest area under the curve (0.911 vs. 0.831 and 0.750, both p<0.05) and specificity (0.935 vs. 0.774 and 0.565, both p<0.05). Moreover, the numbers of HCCs categorized as LR-M decreased from 27 (43.5%) to 14 (22.6%) and 4 (6.5%) using the modified LR-M criteria and ICC scoring system, respectively.

CONCLUSION

The modified LR-M criteria-based multi-parameter ICC scoring system had the highest specificity for diagnosing ICC and reduced the number of HCC cases diagnosed as LR-M category.

Diagnostic performance of magnetic resonance imaging and contrast-enhanced ultrasound in differentiating intrahepatic cholangiocarcinoma from hepatocellular carcinoma: a meta-analysis

PURPOSE

To compare the diagnostic ability between magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS) in distinguishing intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC).

METHODS

Original studies reporting the diagnostic accuracy of MRI and CEUS in differentiating ICC from HCC were identified in PubMed and EMBASE databases. Histopathological examination was used as the reference standard for tumor diagnosis. Study quality was assessed using QUADAS-2 scale. Data were extracted to calculate the pooled diagnostic sensitivity, specificity, and diagnostic odds ratio (DOR) using a bivariate random-effects model, as well as the area under the curve (AUC). Sensitivity analysis, subgroup analysis, meta-regression, and investigation of publication bias were also performed.

RESULTS

A total of 26 studies with 28 data subsets (18 on MRI, 10 on CEUS) were included, consisting of 4169 patients with 1422 ICC lesions and 2747 HCC lesions. Most MRI studies were performed at 3T with hepatobiliary agents, and most CEUS studies used SonoVue as the contrast agent. In MRI, the pooled sensitivity, specificity, DOR, and AUC in distinguishing ICC from HCC were 0.81 (0.79, 0.84), 0.90 (0.88, 0.91), 41.47 (24.07, 71.44), and 0.93 (0.90, 0.96), respectively. The pooled sensitivity, specificity, DOR, and AUC of CEUS were 0.88 (0.84, 0.90), 0.80 (0.78, 0.83), 42.06 (12.38, 133.23), and 0.93 (0.87, 0.99), respectively. Subgroup analysis and meta-regression analysis demonstrated significant heterogeneity among the studies associated with the type of contrast agent in MRI studies. No publication bias was found.

CONCLUSION

Both MRI and CEUS showed excellent diagnostic performance in differentiating ICC from HCC. CEUS showed higher pooled sensitivity and MRI showed higher pooled specificity.

A convenient scoring system to distinguish intrahepatic mass-forming cholangiocarcinoma from solitary colorectal liver metastasis based on magnetic resonance imaging features

OBJECTIVES

To develop and validate a diagnostic scoring system to differentiate intrahepatic mass-forming cholangiocarcinoma (IMCC) from solitary colorectal liver metastasis (CRLM).

METHODS

A total of 366 patients (263 in the training cohort, 103 in the validation cohort) who underwent MRI examination with pathologically proven either IMCC or CRLM from two centers were included. Twenty-eight MRI features were collected. Univariate analyses and multivariate logistic regression analyses were performed to identify independent predictors for distinguishing IMCC from solitary CRLM. The independent predictors were weighted over based on regression coefficients to build a scoring system. The overall score distribution was divided into three groups to show the diagnostic probability of CRLM.

RESULTS

Six independent predictors, including hepatic capsular retraction, peripheral hepatic enhancement, vessel penetrating the tumor, upper abdominal lymphadenopathy, peripheral washout at the portal venous phase, and rim enhancement at the portal venous phase were included in the system. All predictors were assigned 1 point. At a cutoff of 3 points, AUCs for this score model were 0.948 and 0.903 with sensitivities of 96.5% and 92.0%, specificities of 84.4% and 71.7%, positive predictive values of 87.7% and 75.4%, negative predictive values of 95.4% and 90.5%, and accuracies of 90.9% and 81.6% for the training and validation cohorts, respectively. An increasing trend was shown in the diagnostic probability of CRLM among the three groups based on the score.

CONCLUSIONS

The established scoring system is reliable and convenient for distinguishing IMCC from solitary CRLM using six MRI features.

CLINICAL RELEVANCE STATEMENT

A reliable and convenient scoring system was developed to differentiate between intrahepatic mass-forming cholangiocarcinoma from solitary colorectal liver metastasis using six MRI features.

KEY POINTS

• Characteristic MRI features were identified to distinguish intrahepatic mass-forming cholangiocarcinoma (IMCC) from solitary colorectal liver metastasis (CRLM). • A model to distinguish IMCC from solitary CRLM was created based on 6 features, including hepatic capsular retraction, upper abdominal lymphadenopathy, peripheral washout at the portal venous phase, rim enhancement at the portal venous phase, peripheral hepatic enhancement, and vessel penetrating the tumor.

On-Site Diagnostic Ability of CEUS/CT/MRI for Hepatocellular Carcinoma (2019-2022): A Multicenter Study

OBJECTIVES

To compare the on-site diagnostic performance of contrast-enhanced ultrasound (CEUS), computed tomography (CECT), and magnetic resonance imaging (CEMRI) for hepatocellular carcinoma (HCC) across diverse practice settings.

METHODS

Between May 2019 and April 2022, a total of 2085 patients with 2320 pathologically confirmed focal liver lesions (FLLs) were enrolled. Imaging reports were compared with results from pathology analysis. Diagnostic performance was analyzed in defined size, high-risk factors for HCC, and hospital volume categories.

RESULTS

Three images achieved similar diagnostic performance in classifying HCC from 16 types of FLLs, including HCC ≤2.0 cm. For HCC diagnosis at low-volume hospitals and HCC with high-risk factors, the accuracy and specificity of CEUS were comparable to CECT and CEMRI, while the sensitivity of CEUS (77.4 and 89.5%, respectively) was inferior to CEMRI (87.0 and 92.8%, respectively). The diagnostic accuracy of CEUS + CEMRI and CEUS + CECT increased by 7.8 and 6.2% for HCC ≤2.0 cm, 8.0 and 5.0% for HCC with high-risk factors, and 7.4 and 5.5% for HCC at low-volume hospitals, respectively, compared with CEMRI/CECT alone.

CONCLUSIONS

Compared with CECT and CEMRI, CEUS provides adequate diagnostic performance in clinical first-line applications at high-volume hospitals. Moreover, a higher diagnostic performance for HCC is achieved by combining CEUS with CECT/CEMRI compared with any single imaging technique.

A nomogram based on ultrasonographic features and clinical indicators for differentiating mass-forming intrahepatic cholangiocarcinoma and liver metastatic colorectal adenocarcinoma

Objective

This study aimed to develop and validate a nomogram based on ultrasonographic features and clinical indicators to differentiate mass-forming intrahepatic cholangiocarcinoma (MF-ICC) from hepatic metastatic colorectal adenocarcinoma.

Materials and methods

A total of 343 patients with pathologically confirmed MF-ICC or metastatic colorectal adenocarcinoma were enrolled between October 2018 and July 2022. Patients were randomly assigned to training and validation sets at a ratio of 7:3. Preoperative ultrasound features and clinical indicators were retrieved. Univariate logistic regression analysis was employed to select relevant features. Multivariate logistic regression analysis was used to establish a predictive model, which was presented as a nomogram in training sets. The model's performance was assessed in terms of discrimination, calibration, and clinical usefulness.

Results

The study included 169 patients with MF-ICC and 174 with liver metastatic colorectal adenocarcinoma, assigned to training (n=238) and validation (n=105) cohorts. The nomogram incorporated ultrasound features (tumor size, lesion number, echogenicity, tumor necrosis, and rim arterial phase hyperenhancement) and clinical information (serum levels of CEA, CA19-9, CA125). The nomogram demonstrated promising performance in differentiating these two entities in both training and validation sets, with an AUC value of 0.937 (95%CI: 0.907,0.969) and 0.916 (95%CI: 0.863,0.968), respectively. The Hosmer-Lemeshow test and calibration curves confirmed good consistency between predictions and observations. Additionally, decision curve analysis confirmed the nomogram's high clinical practicability.

Conclusion

The nomogram based on ultrasound features and clinical indicators demonstrated good discrimination performance in differentiating MF-ICC from metastatic colorectal adenocarcinoma, which may enhance clinical decision-making process in managing these challenging diagnostic scenarios.

Contrast-Enhanced Imaging in the Management of Intrahepatic Cholangiocarcinoma: State of Art and Future Perspectives

Intrahepatic cholangiocarcinoma (iCCA) represents the second most common liver cancer after hepatocellular carcinoma, accounting for 15% of primary liver neoplasms. Its incidence and mortality rate have been rising during the last years, and total new cases are expected to increase up to 10-fold during the next two or three decades. Considering iCCA's poor prognosis and rapid spread, early diagnosis is still a crucial issue and can be very challenging due to the heterogeneity of tumor presentation at imaging exams and the need to assess a correct differential diagnosis with other liver lesions. Abdominal contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) plays an irreplaceable role in the evaluation of liver masses. iCCA's most typical imaging patterns are well-described, but atypical features are not uncommon at both CT and MRI; on the other hand, contrast-enhanced ultrasound (CEUS) has shown a great diagnostic value, with the interesting advantage of lower costs and no renal toxicity, but there is still no agreement regarding the most accurate contrastographic patterns for iCCA detection. Besides diagnostic accuracy, all these imaging techniques play a pivotal role in the choice of the therapeutic approach and eligibility for surgery, and there is an increasing interest in the specific imaging features which can predict tumor behavior or histologic subtypes. Further prognostic information may also be provided by the extraction of quantitative data through radiomic analysis, creating prognostic multi-parametric models, including clinical and serological parameters. In this review, we aim to summarize the role of contrast-enhanced imaging in the diagnosis and management of iCCA, from the actual issues in the differential diagnosis of liver masses to the newest prognostic implications.

Focal Liver Lesions other than Hepatocellular Carcinoma in Cirrhosis: Diagnostic Challenges

Liver cirrhosis is associated with regenerative nodules and an increased risk of developing hepatocellular carcinoma (HCC). However, other benign and malignant liver lesions may also occur. Differentiating the other lesions from HCC is important for further therapeutic decisions. This review discusses the characteristics of non-HCC liver lesions in cirrhosis and their consequent appearance on contrast-enhanced ultrasonography (CEUS) with consideration of other imaging. Knowledge of this data would be helpful in avoiding misdiagnoses.

Distinctive Metabolism-Associated Gene Clusters That Are Also Prognostic in Intrahepatic Cholangiocarcinoma and Hepatocellular Carcinoma

Objective

To offer new prognostic evaluations by exploring potentially distinctive genetic features of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC).

Methods

There were 12 samples for gene expression profiling processes in this study. These included three HCC lesion samples and their matched adjacent nontumor liver tissues obtained from patients with HCC, as well as three ICC samples and their controls collected similarly. In addition to the expression matrix generated on our own, profiles of other cohorts from The Cancer Genome Atlas (TCGA) program and the Gene Expression Omnibus (GEO) were also employed in later bioinformatical analyses. Differential analyses, functional analyses, protein interaction network analyses, and gene set variation analyses were used to identify key genes. To establish the prognostic models, univariate/multivariate Cox analyses and subsequent stepwise regression were applied, with the Akaike information criterion evaluating the goodness of fitness.

Results

The top three pathways enriched in HCC were all metabolism-related; they were fatty acid degradation, retinol metabolism, and arachidonic acid metabolism. In ICC, on the other hand, additional pathways related to fat digestion and absorption and cholesterol metabolism were identified. Consistent characteristics of such a metabolic landscape were observed across different cohorts. A prognostic risk score model for calculating HCC risk was constructed, consisting of ADH4, ADH6, CYP2C9, CYP4F2, and RDH16. This signature predicts the 3-year survival with an AUC area of 0.708 (95%CI = 0.644 to 0.772). For calculating the risk of ICC, a prognostic risk score model was built upon the expression levels of CYP26A1, NAT2, and UGT2B10. This signature predicts the 3-year survival with an AUC area of 0.806 (95% CI = 0.664 to 0.947).

Conclusion

HCC and ICC share commonly abrupted pathways associated with the metabolism of fatty acids, retinol, arachidonic acids, and drugs, indicating similarities in their pathogenesis as primary liver cancers. On the flip side, these two types of cancer possess distinctive promising biomarkers for predicting overall survival or potential targeted therapies.

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.

Intravenous combined with intrabiliary contrast-enhanced ultrasound in the evaluation of resectability of hilar cholangiocarcinomas

OBJECTIVE

To investigate the application value of combined intravenous contrast-enhanced ultrasound (IV-CEUS) with intrabiliary contrast-enhanced ultrasound (IB-CEUS) in the preoperative evaluation of hilar cholangiocarcinoma (HCCA) resectability.

METHODS

Clinical data from 82 patients with HCCA confirmed by surgery and pathology were retrospectively analyzed. Preoperative IV-CEUS + IB-CEUS and magnetic resonance cholangiopancreatography (MRCP) were performed and the results were compared with surgical and pathological findings.

RESULTS

The accuracy of the Bismuth-Corlette classification confirmed by IV-CEUS + IB-CEUS and MRCP was 95.12% (78/82) and 87.8% (72/82), respectively. The diagnostic precision of IV-CEUS + IB-CEUS was better than MRCP (p = 0.001). The sensitivity, specificity, and precision of CEUS for diagnosing lymph node metastases (72.7%, 93.3%, and 87.8%), intrahepatic metastases (78.6%, 98.5%, and 93.9%), invasion of the hepatic artery (92.9%, 98.5%, and 97.6%) and invasion of the portal vein (93.8%, 98.5%, and 97.6%) of HCCA were, respectively. The consistency between the preoperative evaluation of resectability confirmed by IV-CEUS +IB-CEUS and MRCP was 85.4% (70/82) and 78.0% (64/82), respectively. In addition, the evaluations did not have statistically significant differences (p > 0.05). There were no significant differences between the two evaluations (p = 0.266).

CONCLUSION

IV-CEUS combined with IB-CEUS has significant value in classifying HCCA and evaluating the resectability of lymph node metastases, liver metastases, and vessel invasion.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Contrast-enhanced ultrasound (CEUS) in patients with metastasis-like hepatic alveolar echinococcosis: a cohort study

PURPOSE

Hepatic alveolar echinococcosis (HAE) of the metastasis-like pattern, according to the Echinococcus Ulm classification, is usually discovered as an incidental finding, and the diagnostic differentiation from "true metastases" is difficult. The aim of this study was to investigate whether lesions of the "metastasis-like pattern" in HAE show a typical contrast behavior that can be used for differentiation from metastasis in malignancies.

METHODS

This prospective clinical study included 11 patients with histologically confirmed HAE of the metastasis-like pattern (7 female and 4 male; mean age, 57.1 years; mean disease duration, 59.5 months), who had been examined by B-scan sonography and CEUS, from the National Echinococcosis Registry Germany.

RESULTS

On contrast-enhanced sonography, 11/11 reference lesions showed annular rim enhancement in the arterial and portal venous phases. Throughout the entire 4-min study period, none of the reference lesions showed central contrast enhancement-i.e., all exhibited a complete "black hole sign". A small central scar was seen in 81.8% of cases.

CONCLUSION

In clinically unremarkable patients with incidentally detected metastasis-like lesions of the liver, contrast-enhanced sonographic detection of rim enhancement without central contrast uptake (black hole sign) should be considered evidence supporting a diagnosis of hepatic alveolar echinococcosis with a rare metastasis-like pattern. This can help to differentiate HAE from metastases, especially in high-endemic areas.

Contrast-enhanced ultrasound features predict the prognosis of percutaneous microwave ablation of intrahepatic cholangiocarcinoma

OBJECTIVE

To evaluate the prognostic effect of pre-operative contrast-enhanced ultrasound (CEUS) features on intrahepatic cholangiocarcinoma (ICC) after percutaneous microwave ablation (MWA).

METHODS

A total of ICC 29 patients (average age 56.34 ± 9.78 years old, 33~75 years old) underwent MWA from March 2012 to December 2020, with a total of 58 lesions (0.5-8.1 cm, mean diameter, 2.68 ± 1.59 cm), and their pre-operative CEUS images and clinical data were collected and reviewed. Survival rate, local progression rate, intra- and extrahepatic metastasis rate were evaluated. Uni- and multivariate analysis were used to analyze the prognostic factors affecting the survival of ICC patients with pre-operative CEUS features.

RESULTS

The median follow-up time after MWA was 18.43 months (4.17-93.13 months). 1-, 2-, and 3-year OS rates were 64.4%, 48.1% and 48.1%; 6-, 12-, 18-, 24-, 36-, 48-, and 60-month local progress and extrahepatic metastasis rates were 0.0%, 4.0%, 17.7%, 17.7%, 17.7%, 17.7%, 17.7% and 3.4%, 21.5%, 32.7%, 45.6%, 55.2%, 55.2% and 77.6%, respectively. Uni- and multivariate analysis showed that post-operative extrahepatic metastasis was an important factor for long-term survival of ICC patients after MWA (p = 0.006, 0.01), and Rim-enhancement feature of pre-operative CEUS was identified as an independent predictor of post-operative extrahepatic metastasis and long-term survival (p = 0.02, 0.02).

CONCLUSION

Rim-enhancement feature of pre-operative CEUS is a predictor high post-operative extrahepatic metastasis and poor prognosis through distant microvascular metastasis after MWA of ICC patients.

ADVANCES IN KNOWLEDGE

This study determined the important CEUS features of ICC and analyzed their impact on the prognosis of ICC patients after MWA, providing scientific guidance for better clinical treatment in the future.

Conventional, functional and radiomics assessment for intrahepatic cholangiocarcinoma

Background

This paper offers an assessment of diagnostic tools in the evaluation of Intrahepatic Cholangiocarcinoma (ICC).

Methods

Several electronic datasets were analysed to search papers on morphological and functional evaluation in ICC patients. Papers published in English language has been scheduled from January 2010 to December 2021.

Results

We found that 88 clinical studies satisfied our research criteria. Several functional parameters and morphological elements allow a truthful ICC diagnosis. The contrast medium evaluation, during the different phases of contrast studies, support the recognition of several distinctive features of ICC. The imaging tool to employed and the type of contrast medium in magnetic resonance imaging, extracellular or hepatobiliary, should change considering patient, departement, and regional features. Also, Radiomics is an emerging area in the evaluation of ICCs.

Post treatment studies are required to evaluate the efficacy and the safety of therapies so as the patient surveillance.

Conclusions

Several morphological and functional data obtained during Imaging studies allow a truthful ICC 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.

Role of noninvasive imaging in the evaluation of intrahepatic cholangiocarcinoma: from diagnosis and prognosis to treatment response

INTRODUCTION

Intrahepatic cholangiocarcinoma is the second most common liver cancer. Desmoplastic stroma may be revealed as distinctive histopathologic findings favoring intrahepatic cholangiocarcinoma. Meanwhile, a range of imaging manifestations is often accompanied with rich desmoplastic stroma in intrahepatic cholangiocarcinoma, which can indicate large bile duct ICC, and a higher level of cancer-associated fibroblasts with poor prognosis and weak treatment response.

AREAS COVERED

We provide a comprehensive review of current state-of-the-art and recent advances in the imaging evaluation for diagnosis, staging, prognosis and treatment response of intrahepatic cholangiocarcinoma. In addition, we discuss precursor lesions, cells of origin, molecular mutation, which would cause the different histological classification. Moreover, histological classification and tumor microenvironment, which are related to the proportion of desmoplastic stroma with many imaging manifestations, would be also discussed.

EXPERT OPINION

The diagnosis, prognosis, treatment response of intrahepatic cholangiocarcinoma may be revealed as the presence and the proportion of desmoplastic stroma with a range of imaging manifestations. With the utility of radiomics and artificial intelligence, imaging is helpful for ICC evaluation. Multicentre, large-scale, prospective studies with external validation are in need to develop comprehensive prediction models based on clinical data, imaging findings, genetic parameters, molecular, metabolic, and immune biomarkers.

US-Based Deep Learning Model for Differentiating Hepatocellular Carcinoma (HCC) From Other Malignancy in Cirrhotic Patients

The aim was to build a predictive model based on ultrasonography (US)-based deep learning model (US-DLM) and clinical features (Clin) for differentiating hepatocellular carcinoma (HCC) from other malignancy (OM) in cirrhotic patients. 112 patients with 120 HCCs and 60 patients with 61 OMs were included. They were randomly divided into training and test cohorts with a 4:1 ratio for developing and evaluating US-DLM model, respectively. Significant Clin predictors of OM in the training cohort were combined with US-DLM to build a nomogram predictive model (US-DLM+Clin). The diagnostic performance of US-DLM and US-DLM+Clin were compared with that of contrast enhanced magnetic resonance imaging (MRI) liver imaging and reporting system category M (MRI LR-M). US-DLM was the best independent predictor for evaluating OMs, followed by clinical information, including high cancer antigen 199 (CA199) level and female. The US-DLM achieved an AUC of 0.74 in the test cohort, which was comparable with that of MRI LR-M (AUC=0.84, p=0.232). The US-DLM+Clin for predicting OMs also had similar AUC value (0.81) compared with that of LR-M+Clin (0.83, p>0.05). US-DLM+Clin obtained a higher specificity, but a lower sensitivity, compared to that of LR-M +Clin (Specificity: 82.6% vs. 73.9%, p=0.007; Sensitivity: 78.6% vs. 92.9%, p=0.006) for evaluating OMs in the test set. The US-DLM+Clin model is valuable in differentiating HCC from OM in the setting of cirrhosis.

Differentiation between hepatocellular carcinoma and intrahepatic cholangiocarcinoma using contrast-enhanced ultrasound: A systematic review and meta-analysis

AIM

To explore the diagnostic ability of contrast-enhanced ultrasound (CEUS) in distinguishing intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were systematically searched for studies reporting the diagnostic accuracy of CEUS in differentiating ICC from HCC. The diagnostic ability of CEUS was assessed based on the pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the curve (AUC) with 95% confidence intervals (CIs). The methodologic quality was assessed by the QUADAS-2 tool. Subgroup analyses, meta-regression and investigation of publication bias were performed to identify the source of heterogeneity.

RESULTS

A total of eight studies were included, consisting of 1,116 patients with HCC and 529 with ICC. The general diagnostic performance of CEUS in distinguishing ICC and HCC were as follows: pooled sensitivity, 0.92 (95% CI: 0.84-0.96); pooled specificity, 0.87 (95% CI: 0.79-0.92); pooled PLR, 7.1 (95% CI: 4.1-12.0); pooled NLR, 0.09 (95% CI: 0.05-0.19); pooled DOR, 76 (95% CI: 26-220) and AUC, 0.95(95% CI: 0.93-0.97). Different liver background may be a potential factor that influenced the diagnostic accuracy of CEUS according to the subgroup analysis, with the pooled DOR of 89.67 in the mixed liver background group and 46.87 in the cirrhosis group, respectively. Six informative CEUS features that may help differentiate HCC from ICC were extracted. The three CEUS features favoring HCC were arterial phase hyperenhancement(APHE), mild washout and late washout (>60s); the three CEUS favoring ICC were arterial rim enhancement, marked washout and early washout(<60s). No potential publication bias was observed.

CONCLUSION

CEUS showed great diagnostic ability in differentiating ICC from HCC, which may be promising for noninvasive evaluation of these diseases.

Combined hepatocellular-cholangiocarcinoma: can we use contrast-enhanced ultrasound Liver Imaging Reporting and Data System (LI-RADS) to predict the patient's survival?

OBJECTIVES

To evaluate the relationship between contrast-enhanced (CE) ultrasound Liver Reporting and Data System (LI-RADS) classification of combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and their histopathological component predominance, and to determine if the CEUS LI-RADS category can be used to predict the patient's survival after surgical resection.

METHODS

Between January 2011 and December 2018, medical records and CEUS of patients with pathologically proven cHCC-CCA were studied. The predominance of hepatocellular carcinoma (HCC)/intrahepatic cholangiocarcinoma (ICC) component of cHCC-CCA was analyzed by histopathology. The proportion of HCC-predominant cHCC-CCA in different LI-RADS category was compared by using Fisher's exact test. Factors affecting tumor recurrence were analyzed by Cox proportional hazard model. Disease-free survival (DFS) was estimated by using Kaplan-Meier survival curve and compared by log-rank test.

RESULTS

The study included 37 cHCC-CCA patients (33 men, 4 women; average age, 50.4 ± 11.0 years) and 37 nodules (mean diameter, 6.1 ± 3.9 cm). According to CEUS LI-RADS, 62.2% (23/37), 18.9% (7/37), and 18.9% (7/37) of cHCC-CCA were classified as LR-M, LR-5, and LR-TIV, respectively. The ratio of HCC predominance in LR-5 was 100% (10/10) vs 81.5% (22/27) in the LR-M group (p = 0.591). In our population, LR-5 patients had longer DFS than LR-M and LR-TIV patients combined (median DFS: 18.0 vs 6.4 months, p = 0.016). Multiple lesions (hazard ratio, 3.1; p = 0.007), tumor size (≥ 5 cm, hazard ratio, 4.1; p = 0.003), and CEUS LI-RADS category (LR-M and LR-TIV, hazard ratio, 4.7; p = 0.011) showed independent association with shorter DFS.

CONCLUSION

cHCC-CCA characterized as LR-5 on CEUS tend to represent HCC-predominant tumors with significantly longer disease-free survival compared to cHCC-CCA categorized as LR-M and LR-TIV.

KEY POINTS

• By using the American College of Radiology contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS), majority (30/37, 81.1%) of cHCC-CCA tumors were classified as LR-M or LR-TIV and only 18.9% (7/30) of cHCC-CCA were categorized as LR-5. • Patients with CEUS LR-5 cHCC-CCA had statistically significant longer disease-free time than those with LR-M and TIV cHCC-CCA (median DFS: 18.0 vs 6.4 months, p = 0.016). • Multiple lesions (hazard ratio, 3.1; p = 0.007), tumor size (≥ 5 cm, hazard ratio, 4.1; p = 0.003), and CEUS LI-RADS category (LR-M and LR-TIV, hazard ratio, 4.7; p = 0.011) showed independent association with shorter DFS.