Contrast-enhanced ultrasound in the diagnosis of nodules in liver cirrhosis

MRI for hepatocellular carcinoma and the role of abbreviated MRI for surveillance of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) constitutes the majority of liver cancers and significantly impacts global cancer mortality. While ultrasound (US) with or without alpha-fetoprotein is the mainstay for HCC surveillance, its limitations highlight the necessity for more effective surveillance tools. Therefore, this review explores evolving imaging modalities and abbreviated magnetic resonance imaging (MRI) (AMRI) protocols as promising alternatives, addressing challenges in HCC surveillance.

AREAS COVERED

This comprehensive review delves into the evaluation and challenges of HCC surveillance tools, focusing on non-contrast abbreviated MRI (NC-AMRI) and contrast-enhanced abbreviated MRI protocols. It covers the implementation of AMRI for HCC surveillance, patient preferences, adherence, and strategies for optimizing cost-effectiveness. Additionally, the article provides insights into prospects for HCC surveillance by summarizing meta-analyses, prospective studies, and ongoing clinical trials evaluating AMRI protocols.

EXPERT OPINION

The opinions underscore the transformative impact of AMRI on HCC surveillance, especially in overcoming US limitations. Promising results from NC-AMRI protocols indicate its potential for high-risk patient surveillance, though prospective studies in true surveillance settings are essential for validation. Future research should prioritize risk-stratified AMRI protocols and address cost-effectiveness for broader clinical implementation, alongside comparative analyses with US for optimal surveillance strategies.

Thermal/ultrasound-triggered release of liposomes loaded with Ganoderma applanatum polysaccharide from microbubbles for enhanced tumour ablation

The effectiveness of thermal ablation for the treatment of liver tumours is limited by the risk of incomplete ablation, which can result in residual tumours. Herein, an enhancement strategy is proposed based on the controlled release of Ganoderma applanatum polysaccharide (GAP) liposome-microbubble complexes (GLMCs) via ultrasound (US)-targeted microbubble destruction (UTMD) and sublethal hyperthermic (SH) field. GLMCs were prepared by conjugating GAP liposomes onto the surface of microbubbles via biotin-avidin linkage. In vitro, UTMD promotes the cellular uptake of liposomes and leads to apoptosis of M2-like macrophages. Secretion of arginase-1 (Arg-1) and transforming growth factor-beta (TGF-β) by M2-like macrophages decreased. In vivo, restriction of tumour volume was observed in rabbit VX2 liver tumours after treatment with GLMCs via UTMD in GLMCs + SH + US group. The expression levels of CD68 and CD163, as markers of tumour-associated macrophages (TAMs) in the GLMCs + SH + US group were reduced in liver tumour tissue. Decreased Arg-1, TGF-β, Ki67, and CD31 factors related to tumour cell proliferation and angiogenesis was evident on histological analysis. In conclusion, thermal/US-triggered drug release from GLMCs suppressed rabbit VX2 liver tumour growth in the SH field by inhibiting TAMs, which represents a potential approach to improve the effectiveness of thermal ablation.

Can Modifications of LR-M Criteria Improve the Diagnostic Performance of Contrast-Enhanced Ultrasound LI-RADS for Small Hepatic Lesions up to 3 cm?

OBJECTIVE

To assess the diagnostic performance of the contrast-enhanced ultrasound liver imaging reporting and data system (CEUS LI-RADS) version 2017 for small hepatic lesions of ≤3 cm before and after changing the LR-M criteria.

METHODS

We retrospectively analyzed the CEUS examination of 179 patients who were at high risk of hepatocellular carcinoma (HCC) with focal hepatic lesions ≤3 cm (194 lesions in total) and evaluated the diagnostic capability of the American College of Radiology and modified CEUS LI-RADS algorithms.

RESULTS

Revision of the early washout time to 45 seconds increased the sensitivity of LR-5 in predicting HCC (P = .004), with no significant decrease in specificity (P = .118). It also made better the specificity of LR-M in predicting non-HCC malignancies (P = .001), with no significant decrease in sensitivity (P = .094). However, using within 3 minutes as the criterion for marked washout time improved the LR-5 sensitivity (P < .001) but decreased its specificity (P = .009) in predicting HCC, whereas the specificity of LR-M in predicting non-HCC malignancies increased (P < .001), but the sensitivity decreased (P = .027).

CONCLUSIONS

CEUS LI-RADS (v2017) is a valid method for predicting HCC risk in high-risk patients. The diagnostic performance of LR-5 and LR-M could boost when the early washout time is revised to 45 seconds.

Clinical characteristics of human fascioliasis in Egypt

There is a lack of epidemiological data on fascioliasis in Egypt regarding disease characteristics and treatment outcomes across different governorates. We aimed to identify the demographic, epidemiologic, clinical, laboratory, and radiological characteristics and treatment outcomes of patients diagnosed with fascioliasis in Egypt. Data on human fascioliasis were collected retrospectively from patients' medical records in the period between January 2018 and January 2020. The study included 261 patients. More than 40% of enrolled patients were in the age group of 21-40 years old. Geographically, 247 (94.6%) were from Assiut Governorate with 69.3% were from rural areas. The most frequent symptoms were right upper quadrant pain (96.9%), and fever (80.1%). Eosinophilia was found in 250 cases (95.8%). Hepatic focal lesions were detected in 131 (50.2%); out of them 64/131 (48.9%) had a single lesion. All patients received a single dose of 10 mg/kg of triclabendazole, 79.7% responded well to a single dose, while in 20.3% a second ± a third dose of treatment was requested. After therapy, there was a reduction in leucocytes, Fasciola antibodies titer, eosinophilic count, bilirubin, and liver enzymes with an increase in hemoglobin level. According to our findings, a high index of suspicion should be raised in cases with fever, right upper abdominal pain, and peripheral eosinophilia, and further imaging workup is mandated to detect hepatic focal lesions. Prompt treatment by triclabendazole can serve as a standard-of-care regimen even for suspected cases.

Current Concepts of Precancerous Lesions of Hepatocellular Carcinoma: Recent Progress in Diagnosis

The most common cause of hepatocellular carcinoma (HCC) is chronic hepatitis and cirrhosis. It is proposed that precancerous lesions of HCC include all stages of the disease, from dysplastic foci (DF), and dysplastic nodule (DN), to early HCC (eHCC) and progressed HCC (pHCC), which is a complex multi-step process. Accurately identifying precancerous hepatocellular lesions can significantly impact the early detection and treatment of HCC. The changes in high-grade dysplastic nodules (HGDN) were similar to those seen in HCC, and the risk of malignant transformation significantly increased. Nevertheless, it is challenging to diagnose precancerous lesions of HCC. We integrated the literature and combined imaging, pathology, laboratory, and other relevant examinations to improve the accuracy of the diagnosis of precancerous lesions.

Hydralazine-augmented contrast ultrasound imaging improves the detection of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) detection with B-mode and contrast-enhanced ultrasound (CUS) imaging often varies between subjects, especially in patients with background cirrhosis. Various factors contribute to this variability, including the tumor blood flow, tumor size, internal echoes, and its location in livers with diffuse fibro-cirrhotic changes.

OBJECTIVE

Towards improving lesion detection, this study evaluates a vasodilator, hydralazine, to enhance the visibility of HCC by reducing its blood flow relative to the surrounding liver tissue.

METHODS

HCC were analyzed for tumor visibility measured for B-mode, CUS, and hydralazine-augmented-contrast ultrasound (HyCUS) in an autochthonous HCC rat model. 21 tumors from 12 rats were studied. B-mode and CUS images were acquired before hydralazine injection. Rats received an intravenous hydralazine injection of 5 mg/kg, then images were acquired 20 min later. Four rats were used as controls. The difference in echo intensity of the lesion and the surrounding tissue was used to determine the visibility index (VI).

RESULTS

The visibility index for HCC was found to be significantly improved with the use of HyCUS imaging compared to traditional B-mode and CUS imaging. The visibility index for HCC was 16.5 ± 2.8 for HyCUS, compared to 5.3 ± 4.8 for B-mode and 4.1 ± 3.8 for CUS. The differences between HyCUS and the other imaging modalities were statistically significant, with p-values of 0.001 and 0.02, respectively. Additionally, when compared to control cases, HyCUS showed higher discrimination of HCC (VI = 6.4 ± 1.2) with a p-value of 0.003, while B-mode (VI = 6.7 ± 1.4, p = 0.5) and CUS (VI = 6.4 ± 1.2, p = 0.3) showed lower discrimination.

CONCLUSION

Vascular blood flow modulation by hydralazine enhances the visibility of HCC. HyCUS offers a potential problem-solving method for detecting HCC when B-mode and CUS are unsuccessful, especially with background fibro-cirrhotic liver disease. Future evaluation of the approach in humans will determine its translatability for clinical applications.

Contrast-enhanced ultrasound for assessing blood flow modulation of hepatocellular carcinoma by hydralazine

Modulating aberrant tumor microvasculature provides unique opportunities for enhancing ultrasound imaging of hepatocellular carcinoma (HCC). This study aims to use contrast-enhanced ultrasound to evaluate the potential of a potent vasodilator, hydralazine, to attenuate blood flow in HCC while enhancing it in the surrounding liver tissue. The "steel effect," where blood flow is diverted from the lesion to the surrounding tissue aims to enhance lesion-tissue contrast. Methods: HCC was induced in six rats by oral ingestion of diethylnitrosamine for 12 weeks. 10 tumors were studied to assess the enhancement in HCC tumors and surrounding tissue. Contrast-enhanced ultrasound images (CEUS) of each tumor were acquired before and after hydralazine injection. The enhancement of images was analyzed for the qualitative and quantitative assessment of HCC enhancement. Peak enhancement (PE) was calculated, representing the maximum signal intensity reached during the transit of the contrast bolus for both the tumor and the surrounding tissue. Intravenous administration of hydralazine significantly reduced CEUS signals in HCC tumors. The visual examination of images showed that the enhancement of tumors dramatically decreased after hydralazine injection. On the other hand, the surrounding tissue showed an increased enhancement. PE for the HCC changed from (71.8 ± 5) pre hydralazine to (28.7± 4.9), a 61.7% reduction after hydralazine injection, p=0.01. Future studies validating the technique in clinical settings for enhancing lesion-tissue contrast may allow physicians greater precision and accuracy in HCC surveillance for early detection of small tumors.

Application of DCE-US using the LI-RADS for patients with liver nodules at high risk for hepatocellular carcinoma: A preliminary study and comparison with visual interpretation

OBJECTIVE

To explore the value of dynamic contrast-enhanced ultrasound (DCE-US) for the Liver Imaging Reporting and Data System (LI-RADS).

METHODS

We included 220 liver nodules at high risk for hepatocellular carcinoma (HCC) from January 2019 to October 2021. Visual interpretation and DCE-US-based quantitative categories using VueBox® software were compared for consistency, nodule enhancement intensity, and washout onset following the contrast-enhanced ultrasound LI-RADS. Taking the cut-off value of the ROC curve on washout onset as the time criterion of early washout of LR-M nodules, analyzed the diagnostic performance of LR-5 for HCC and compared it to that of washout onset within 60 s.

RESULTS

The LI-RADS visual and DCE-US interpretation results showed good consistency (Kappa = 0.730), but differed significantly in determining the LR-5 washout onset (91.2 ± 30.2 vs. 82.0 ± 32.8 s, P = 0.020) and detecting early washout (<60 s) in 196 nodules (P = 0.047). Distinguishing HCC from non-HCC malignancies had: area under the ROC curve, 0.85 (95 % confidence interval, 0.8-0.9); Youden index, 0.69; cut-off value, 48 s; sensitivity, 74.4 %; specificity, 95.0 %. When LR-M diagnosis used washout onset within 48 s, LR-5 diagnosis had sensitivity, 72.8 %; specificity, 95.0 %; positive predictive value, 98.5 %; showing a higher sensitivity than with washout onset in 60 s (62.2 %; P = 0.033).

CONCLUSION

DCE-US and visual interpretations showed high consistency in LI-RADS categories but differed in assessing the washout time. According to the DCE-US interpretation, the diagnostic performance of LR-5 could be improved using washout onset of 48 s for LR-M.

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.

Differentiation of Malignant and Benign Orbital Space-Occupying Lesions Using Contrast-Enhanced Ultrasound: Added Value From a Time-Intensity Curve-Based Quantitative Analysis

OBJECTIVES

To evaluate the value of time-intensity curve (TIC) analysis of contrast-enhanced ultrasound (CEUS) signal to differentiate malignant from benign orbital space-occupying lesions.

METHODS

The CEUS signal of 111 patients with orbital space-occupying lesions was retrospectively analyzed using SonoLiver software. TIC-related parameters such as the arrival time (AT), rise time (RT), time to peak (TTP), maximum intensity (IMAX), mean transit time (mTT), slope of the increase (RS), and slope of the decrease (DS) were compared between the malignant and benign groups. Receiver operating characteristic (ROC) curve analysis was used to acquire the cutoff values of these parameters for differential diagnosis.

RESULTS

TIC patterns were characterized by fast increase and fast decrease in signal intensity in the malignant group, fast increase and a slow decrease in signal intensity in the benign group. The differences in the IMAX, RS, DS, mTT, TTP, and RT between the 2 groups were statistically significant (p <.01), while the difference in the AT were not (p = .672). ROC curve analysis showed that IMAX = 427.20, DS = 34.72, and mTT = 33.55 were the best cutoff values for differential diagnosis of malignant and benign space-occupying lesions. The accuracy rate of CEUS visual evaluation for differential diagnosis was 66.67% (74/111), while TIC quantitative analysis could effectively improve the accuracy to 89.19% (99/111).

CONCLUSIONS

TIC analysis can improve CEUS efficiency to differentiate malignant from benign orbital space-occupying lesions.

Contrast-Enhanced Intraoperative Ultrasonography with Kupffer Phase May Change Treatment Strategy of Metastatic Liver Tumors - A Single-Centre Prospective Study

Aim

To compare the diagnostic performance of contrast-enhanced intraoperative ultrasonography (CE-IOUS) with Kupffer phase in metastatic liver tumours.

Methods

Twenty-seven consecutive patients with liver metastasis were prospectively recruited from November 2019 to July 2020 in the Department of HPB, Beijing Hospital. MRI and Contrast Enhanced Ultrasonography (CEUS) were obtained preoperatively, and the diagnosis was made by radiologists independently and blindly. Intraoperative ultrasonography (IOUS) and CE-IOUS with Sonazoid were done by the same sophisticated surgeon and sonographer and Kupffer phase was used to detect lesions. The sensitivity and specificity to detect lesions were compared between different radiologic methods. Then, the changes in treatment strategy due to CE-IOUS with Sonazoid were analysed.

Results

Twenty-seven patients were included. In MRI, 91 lesions were detected with sensitivity 93.3% (70/75) and specificity 68.8% (11/16). In CEUS, it was 97.1% (68/70) and 86.7% (13/15) in 85 lesions. Meanwhile, in the Kupffer phase in CE-IOUS, 99 lesions were found and 8 new lesions were discovered in 7 cases, with sensitivity 97.5% (80/82) and specificity 94.1% (16/17). The four imaging methods showed no statistic significance in sensitivity and specificity in detecting lesions (Cochran’s Q 10.825, P=0.055). Treatment strategies were altered in 7 patients, 6 achieved R0 resection or ablation, and 1 patient changed from planned R0 resection to palliative surgery.

Conclusion

CE-IOUS may play a similar or even better role than other radiological methods in diagnosing liver metastasis. The CE-IOUS using Sonazoid demonstrated a high sensitivity and specificity for finding occult metastases intraoperatively and changing the treatment strategy.

The Application Value of Contrast-Enhanced Ultrasound in Testicular Occupied Lesions

Objective

To discuss the clinical application value of contrast-enhanced ultrasound (CEUS) in testicular occupied lesions.

Methods

Nine conventional-ultrasound-found testicular occupied lesions which underwent CEUS meantime were analyzed retrospectively. The CEUS perfusion pattern was compared with the surgical pathological result or follow-up findings.

Results

Among all the 9 testicular occupied lesions, there were 5 testicular malignant tumors, 1 testicular benign tumor, 1 testicular tuberculosis, and 2 testicular hematomas. CEUS diagnosed 6 testicular malignant tumors, 1 testicular benign tumor, and 2 testicular hematomas, and its diagnostic accuracy was about 88.9%.

Conclusion

CEUS has high clinical application value in the differential diagnoses of benign and malignant testicular occupied lesions.

Transitional care of biliary atresia

Worldwide native liver survival (NLS) for young adults (>20 years) with biliary atresia varies between 14% and 44% with the majority of patients developing complications in adulthood. Cholangitis and portal hypertension with variceal bleeding are the most common complications and development of these during adolescence associated with the need for liver transplantation during adulthood. Adult listing criteria, typically developed on the background of adult liver disease might not be applicable to this patient population and leads to longer waiting time and risk of deterioration of their medical condition. Current data on growth and puberty in young people with biliary atresia surviving with native liver are rare. Pregnancy has been associated with serious complications in particular for those patients with advanced liver disease and, close follow up by specialist teams recommended. The long-term effect of having a chronic liver disease such as biliary atresia on neuro-cognitive and pubertal development has not been sufficiently explored to date despite reports of a high prevalence of additional educational needs in this cohort. In addition, patients and parents report inferior health related quality of life compared to healthy peers and similar to that of children post liver transplantation. Moving on from paediatric to adult services is challenging for young people and their parents and adult health professionals might not be familiar with the condition and complications. Young people deserve to be looked after by specialist, multidisciplinary services who provide holistic care and address their psychosocial needs in addition to the medical needs.

Value of Perfusion Parameters for Differentiating Hepatocellular Carcinoma and Liver Metastasis With Hypervascularity and a Normal Hepatic Background on Contrast-Enhanced Ultrasound Imaging

OBJECTIVES

To retrospectively evaluate the value of contrast-enhanced ultrasound (CEUS) perfusion parameters in the differential diagnosis of hepatocellular carcinomas (HCCs) and metastatic liver tumors (MLTs) with hypervascularity.

METHODS

Sixty-seven HCCs and 55 MLTs with arterial homogeneous/heterogeneous hyperenhancement on CEUS imaging and a normal liver background were included in this retrospective study. Six CEUS perfusion parameters were compared between HCCs and MLTs with different sizes and HCC differentiations: rise time (RT), time to peak (TTP), mean transit time, wash-out time (WT), maximum intensity (IMAX), and area under the curve (AUC). The area under the receiver operating characteristic curve (AUROC) was determined to compare the diagnostic efficacy of the parameters.

RESULTS

The RT, TTP, and WT were significant longer and the IMAX and AUC were significantly higher in HCCs than in MLTs. In distinguishing between HCCs and MLTs, the AUROC was highest for the WT (0.922; sensitivity, 85.1%; specificity, 89.6%); the AUC and IMAX had the second and third highest AUROCs (AUC: 0.855; sensitivity, 76.1%; specificity, 80.6%; IMAX: 0.827; sensitivity, 76.1%; specificity, 77.6%). The AUROC was lowest for the TTP and RT (TTP: 0.719; sensitivity, 70.1%; specificity, 61.2%; RT: 0.707; sensitivity, 67.2%; specificity, 65.7%). In HCCs, both the tumor size and degree of differentiation affected the IMAX, AUC, and WT. In MLTs, perfusion parameters were not influenced by the tumor size.

CONCLUSIONS

In HCCs and MLTs with hypervascularity and a normal liver background on CEUS imaging, various CEUS perfusion parameters, including IMAX, AUC, WT, RT, and TTP, differed significantly between tumor types. The WT may be the most useful parameter for differentiating between these tumors.

Contrast-enhanced ultrasound of liver lesions in children

Initial pediatric imaging of the liver heavily relies on ultrasonography (US) because it is free of ionizing radiation, easily portable and readily available. Although conventional US (gray-scale and color Doppler) is often an excellent screening tool, its relative low specificity compared to CT/MRI limits liver lesion characterization. The United States Food and Drug Administration's recent approval of an intravenous US contrast agent for pediatric liver lesion characterization (sulfur hexafluoride lipid-type A microspheres) and its excellent safety profile have spurred increased interest in contrast-enhanced US for definitive diagnosis of pediatric liver lesions. This review focuses on the safety of contrast-enhanced US, role of contrast-enhanced US in the evaluation of focal liver lesions, basic contrast-enhanced US technique for liver imaging, and interpretation principles. The authors review common focal liver lesions, with special attention to the role of contrast-enhanced US in the pediatric oncology population.

A Prospective Assessment of the Diagnostic Value of Contrast-Enhanced Ultrasound, Dynamic Computed Tomography and Magnetic Resonance Imaging for Patients with Small Liver Tumors

AIM

This prospective study assessed the diagnostic value of contrast-enhanced ultrasound (CEUS) using long Kupffer phase enhancement for adults with liver tumor size of less than 3 cm. Performance comparisons were also conducted with dynamic computed tomography (CT) and magnetic resonance imaging (MRI).

BACKGROUND

CEUS has emerged as a reliable image modality, since the development of second-generation contrast medium with long Kupffer phase enhancement. Nonetheless, dynamic CT and MRI are currently the standard imaging tools for the diagnosis of liver cancers, and the diagnostic value of CEUS for liver cancer has yet to be universally accepted.

METHODS

Sixty-six adult patients suspected of having liver tumors smaller than 3 cm underwent CEUS, dynamic CT, and MRI examinations independently. Subsequent tumor biopsies were used to verify the diagnostic performance of the three imaging modalities.

RESULTS

The diagnostic odds ratio (DOR, 95% CI) for hepatocellular carcinoma were as follows: CEUS (52.8, 11.4-243), CT (29.29, 7.36-116), and MRI (19.43, 5.44-69.4); for metastasis: CEUS (200, 19.1-2095), CT (24, 5.05-114), and MRI (32, 6.56-156); and all liver malignancy: CEUS (260, 12.7-5310), CT (2.57, 0.55-12.1), and MRI (5.22, 1.25-21.8). CEUS achieved the best differentiation performance.

CONCLUSIONS

CEUS outperformed dynamic CT and MRI in terms of diagnostic performance when dealing with small liver tumors (<3 cm).

Analysis of B-ultrasound and contrast-enhanced ultrasound characteristics of different hepatic neuroendocrine neoplasm

BACKGROUND

Hepatic neuroendocrine neoplasm (hNEN) is a highly heterogeneous tumor. The exact identification of the source and malignant degree of hNEN is important. However, there is a lack of information regarding diagnosis of hNEN with imaging. In addition, no studies have compared the imaging between hNEN and hepatocellular carcinoma (HCC) and among different sources and malignant degrees of hNEN.

AIM

To compare the ultrasound characteristics between hNEN and HCC and among different sources and malignant degrees of hNEN.

METHODS

A total of 55 patients with hNEN were recruited and defined as the hNEN group. Among them, 35 cases of hNET were defined as the hNET group. Twenty cases of hepatic neuroendocrine carcinoma (hNEC) were defined as the hNEC group. Among the 55 lesions, 29 were transferred from the pancreas, 20 were from the gastrointestinal tract, and six were from other sites. In total, 55 patients with HCC were recruited and defined as the HCC group. The characteristic differences of B-mode ultrasound and contrast-enhanced ultrasound (CEUS) between hNEN and HCC and among different sources and malignant degrees of hNEN were compared.

RESULTS

In the hNEN group, the proportions of multiple liver lesions, unclear borders, and high echo lesions were higher than those in the HCC group. The proportions of non-uniform echo and peripheral acoustic halo were lower than those in the HCC group (P < 0.05). The washout to iso-enhancement time and washout to hypo-enhancement time were lower than those in the HCC group (P < 0.05). The characteristics of B-ultrasound and CEUS among different sources of hNEN were similar, and the differences were not statistically significant (P > 0.05). B-mode ultrasound characteristics of hNET and hNEC were similar. The proportions of low enhancement at portal venous phase, non-uniform enhancement forms, and combined tumor vasculature in the hNEC group were larger than those in the hNEN group (P < 0.05).

CONCLUSION

Compared with HCC, hNEN showed multiple intrahepatic lesions, uniform high echo, uniform high enhancement at arterial phase, and rapid washout. Low enhancement at portal venous phase, overall non-uniform enhancement form, and the proportion of combined tumor vasculature in hNEC were larger than those in hNET.

Contrast-Enhanced Ultrasound to Monitor Early Recurrence of Primary Hepatocellular Carcinoma after Curative Treatment

Objective

To evaluate contrast-enhanced ultrasound (CEUS) for monitoring early intrahepatic recurrence of primary hepatocellular carcinoma (HCC) after curative treatment.

Methods

We prospectively analyzed 97 patients (124 nodules) with primary HCC who underwent hepatic resection or radiofrequency ablation and subsequently experienced intrahepatic recurrence. Patients were assessed with conventional ultrasound and CEUS. They were also assessed with contrast-enhanced computed tomography (CECT) and/or magnetic resonance imaging (MRI). The image characteristics of CEUS of recurrent hepatocellular carcinoma and high-grade dysplastic nodules (HGDNs) were analyzed. In addition, the ability of CEUS and CECT/MRI to assess internal artery vascularization in recurrent disease was compared.

Results

CEUS of recurrent hepatocellular carcinoma showed hyperenhancement in the arterial phase in 96 of 99 nodules, and it showed hypo- or isoenhancement for portal venous and delayed phases. The most common enhancement patterns were “fast-in and slow-out” and “fast-in and fast-out”. Based on the arterial hyperenhancement of lesions and with clinical data such as patient history of HCC and increased level of serum alpha-fetoprotein, the diagnostic accuracy of CEUS for recurrent HCC was significantly higher than that based on the enhancement pattern of “fast-in and fast-out”. CEUS of HGDNs showed local or global hyperenhancement during the arterial phase, isoenhancement during the portal venous phase, and isoenhancement or slight hypoenhancement during the delayed phase. The enhancement pattern was “fast-in and slow-out”. In some cases, it was difficult to differentiate HGDNs from recurrent disease using CEUS. Vascularization in recurrent disease was significantly higher when assessed by CEUS than when assessed with CECT/MRI (P < 0.05). For detecting recurrent disease, CEUS showed sensitivity of 97.0%, specificity of 68.0%, positive predictive value of 92.3%, and negative predictive value of 85.0%. The corresponding parameters for CECT/MRI were 71.7%, 72.0%, 88.8%, and 39.1%.

Conclusion

Intrahepatic recurrent HCC and HGDNs with diameter ≤ 3.0 cm have a characteristic appearance on CEUS. This imaging modality may be effective for monitoring early intrahepatic recurrence after curative treatment of primary HCC.

Diagnosis of congenital and acquired focal lesions in the neck, abdomen, and pelvis with contrast-enhanced ultrasound: a pictorial essay

Contrast-enhanced ultrasound (CEUS) is a versatile imaging modality that improves the diagnostic potential of conventional ultrasound. It allows for portable imaging at the bedside. In this paper, we illustrate how CEUS can be used in evaluating several focal lesions in the pediatric population, including liver hemangioma, telangiectasias, splenic hamartomas, and bladder lesions. We describe the ultrasound findings and contrast enhancement patterns associated with these lesions. Findings are correlated with MRI, CT, and/or pathology when available. This paper demonstrates the value of CEUS in improving characterization of many focal lesions in the pediatric population.

CONCLUSION

CEUS is a valuable bedside technique for use in the pediatric population to evaluate focal lesions in various organs, and will allow for safe, more efficient diagnostic imaging. What is Known: • CEUS offers many advantages over CT and MRI and is underutilized in the United States. • It is only FDA approved for vesicoureteral reflux and liver in the pediatric population. However, off label uses are well described. What is New: • This pictorial essay describes ultrasound findings and contrast enhancement patterns associated with liver hemangioma, liver telangiectasia, splenic hamartoma, hemorrhagic ovarian cyst, urachal remnant, spinning top urethras, and kaposiform hemangioendothelioma. • We demonstrate the utility of CEUS in expanding the diagnostic potential of conventional ultrasound.

Evaluation of integrated color-coded perfusion analysis for contrast-enhanced ultrasound (CEUS) after percutaneous interventions for malignant liver lesions: First results

BACKGROUND

 With the rising number of percutaneous ablation therapies in malignant liver lesions there is a need of reliable diagnostics after the intervention to differentiate between reactive changes and tumor.

PURPOSE

To assess the success of percutaneous ablation therapies for malignant liver lesions using CEUS with perfusion analysis.

MATERIAL AND METHODS

Retrospective analysis of perfusion analysis for 67 patients with 94 malignant liver lesions, treated with ablation therapies. The lesions were 70 hepatocellular carcinomas (HCC), 18 metastases, 4 cholangiocellular carcinomas (CCC), 2 lesions remained unclear. CEUS was performed after bolus injection of 1.6-2.4 ml of sulfur-hexafluoride microbubbles. The perfusion analysis was calculated using Peak, TTP, mTT and AUC with integrated software during the late arterial to early portal-venous phase for approximately 9 sec (5-15 sec). For the evaluation of the success after percutaneous treatment the perfusion results were compared to the follow-up control after 6 months with CT and MRI and CEUS.

RESULTS

Perfusion analyses after percutaneous treatment of malignant liver lesions showed highly significant perfusion differences when comparing the center to the surrounding tissue and the margins (p<0.0001) for Peak and also for AUC. 62 lesions were successfully treated, meaning there was no local recurrence after 6 months. In cases of residual tumor CEUS showed a nodular marginal enhancement, the corresponding perfusion analyses showed nodular red and yellow pseudo-color shades.

CONCLUSIONS

Using CEUS and perfusion analysis, a critical analysis of post-ablation defects in malignant liver lesions is possible. With the help of pseudo-colors, remaining tumor-vascularization can be detected.

Noninvasive imaging of hepatocellular carcinoma: From diagnosis to prognosis

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major public health problem worldwide. Hepatocarcinogenesis is a complex multistep process at molecular, cellular, and histologic levels with key alterations that can be revealed by noninvasive imaging modalities. Therefore, imaging techniques play pivotal roles in the detection, characterization, staging, surveillance, and prognosis evaluation of HCC. Currently, ultrasound is the first-line imaging modality for screening and surveillance purposes. While based on conclusive enhancement patterns comprising arterial phase hyperenhancement and portal venous and/or delayed phase wash-out, contrast enhanced dynamic computed tomography and magnetic resonance imaging (MRI) are the diagnostic tools for HCC without requirements for histopathologic confirmation. Functional MRI techniques, including diffusion-weighted imaging, MRI with hepatobiliary contrast agents, perfusion imaging, and magnetic resonance elastography, show promise in providing further important information regarding tumor biological behaviors. In addition, evaluation of tumor imaging characteristics, including nodule size, margin, number, vascular invasion, and growth patterns, allows preoperative prediction of tumor microvascular invasion and patient prognosis. Therefore, the aim of this article is to review the current state-of-the-art and recent advances in the comprehensive noninvasive imaging evaluation of HCC. We also provide the basic key concepts of HCC development and an overview of the current practice guidelines.

Abdominal imaging findings in adult patients with Fontan circulation

Abstract

The Fontan procedures, designed to treat paediatric patients with functional single ventricles, have markedly improved the patient’s survival into adulthood. The physiology of the Fontan circuit inevitably increases systemic venous pressure, which may lead to multi-system organ failure in the long-term follow-up. Fontan-associated liver disease (FALD) can progress to liver cirrhosis with signs of portal hypertension. Focal nodular hyperplasia-like nodules commonly develop in FALD. Imaging surveillance is often performed to monitor the progression of FALD and to detect hepatocellular carcinoma, which infrequently develops in FALD. Other abdominal abnormalities in post-Fontan patients include protein losing enteropathy and pheochromocytoma/paraganglioma. Given that these abdominal abnormalities are critical for patient management, it is important for radiologists to become familiar with the abdominal abnormalities that are common in post-Fontan patients on cross-sectional imaging.

Teaching points

• Fontan procedure for functional single ventricle has improved patient survival into adulthood.

• Radiologists should be familiar with unique imaging findings of Fontan-associated liver disease.

• Focal nodular hyperplasia-like nodules commonly develop in Fontan-associated liver disease.

• Hepatocellular carcinoma, protein-losing enteropathy, pheochromocytoma/paraganglioma may develop.

Electronic supplementary material

The online version of this article (10.1007/s13244-018-0609-2) contains supplementary material, which is available to authorized users.

Machine learning for medical ultrasound: status, methods, and future opportunities

Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modality in the practice of medicine. It is low-cost, non-ionizing, portable, and capable of real-time image acquisition and display. US is a rapidly evolving technology with significant challenges and opportunities. Challenges include high inter- and intra-operator variability and limited image quality control. Tremendous opportunities have arisen in the last decade as a result of exponential growth in available computational power coupled with progressive miniaturization of US devices. As US devices become smaller, enhanced computational capability can contribute significantly to decreasing variability through advanced image processing. In this paper, we review leading machine learning (ML) approaches and research directions in US, with an emphasis on recent ML advances. We also present our outlook on future opportunities for ML techniques to further improve clinical workflow and US-based disease diagnosis and characterization.

Contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) 2017 - a review of important differences compared to the CT/MRI system

Medical imaging plays an important role in the diagnosis and management of hepatocellular carcinoma (HCC). The Liver Imaging Reporting and Data System (LI-RADS) was initially created to standardize the reporting and data collection of CT and MR imaging for patients at risk for HCC. As contrast-enhanced ultrasound (CEUS) has been widely used in clinical practice, it has recently been added to the LI-RADS. While CEUS LI-RADS shares fundamental concepts with CT/MRI LI-RADS, there are key differences between the modalities reflecting dissimilarities in the underlying methods of image acquisition and types of contrast material. This review introduces a recent update of CEUS LI-RADS and explains the key differences from CT/MRI LI-RADS.

Interval Magnetic Resonance Imaging: an Alternative to Guidelines for Indeterminate Nodules Discovered in the Cirrhotic Liver

BACKGROUND

Current guidelines for the management of indeterminate nodules discovered on surveillance imaging recommend alternate imaging modality or biopsy. This study evaluates the use of short interval MRI rather than immediate CT or biopsy.

METHOD

This retrospective cohort study examines outcomes of 111 patients with indeterminate nodules reviewed by a single institution's Liver Tumor Board 2011-2016. Analysis was focused on outcomes stratified by management decision.

RESULTS

The tumor board recommended biopsy or immediate repeat CT imaging in 13 (12%), 3-month interval MRI in 64 (58%) and 6-month interval MRI for 34 (30%) patients. Twenty-eight (29%) patients in the interval MRI subgroups were diagnosed with hepatocellular carcinoma (HCC) during the period of follow-up, and 21 (75%) of these were located within the original indeterminate nodule. The median time to diagnosis was 6.5 months. Twenty-three (82%) were eligible for potentially curative therapy at the time of HCC diagnosis. Delay in HCC diagnosis was not the reason for inability to provide potentially curative therapy in any patient.

CONCLUSION

This study supports the judicious use of interval MRI at 3 or 6 months in patients with liver cirrhosis and an indeterminate liver nodule rather than immediate CT scan or biopsy.

Diagnostic accuracy of contrast-enhanced ultrasound for the differential diagnosis of hepatocellular carcinoma: ESCULAP versus CEUS-LI-RADS

OBJECTIVE

A comparison is made of two contrast-enhanced ultrasound (CEUS) algorithms for the diagnosis of hepatocellular carcinoma (HCC) in high-risk patients: Erlanger Synopsis of Contrast-enhanced Ultrasound for Liver lesion Assessment in Patients at Risk (ESCULAP) and American College of Radiology Contrast-Enhanced Ultrasound-Liver Imaging Reporting and Data System (ACR-CEUS-LI-RADSv.2016).

PATIENTS AND METHODS

Focal liver lesions in 100 high-risk patients were assessed using both CEUS algorithms (ESCULAP and CEUS-LI-RADSv.2016) for a direct comparison. Lesions were categorized according to size and contrast enhancement in the arterial, portal venous and late phases.For the definite diagnosis of HCC, categories ESCULAP-4, ESCULAP-Tr and ESCULAP-V and CEUS-LI-RADS-LR-5, LR-Tr and LR-5-V were compared. In addition, CEUS-LI-RADS-category LR-M (definitely/probably malignant, but not specific for HCC) and ESCULAP-category C [intrahepatic cholangiocellular carcinoma (ICC)] were compared.Histology, CE-computed tomography and CE-MRI served as reference standards.

RESULTS

The reference standard among 100 lesions included 87 HCCs, six ICCs and seven non-HCC-non-ICC-lesions. For the diagnosis of HCC, the diagnostic accuracy of CEUS was significantly higher with ESCULAP versus CEUS-LI-RADS (94.3%/72.4%; p<0.01). Sensitivity, specificity and positive predictive value (PPV) and negative predictive value for ESCULAP/CEUS-LI-RADS were 94.3%/72.4%; 61.5%/69.2%; 94.3%/94%; and 61.5%/27.3%, respectively.The diagnostic accuracy for ICC (LR-M/ESCULAP-C) was identical with both algorithms (50%), with higher PPV for ESCULAP-C versus LR-M (75 vs. 50%).

CONCLUSION

CEUS-based algorithms contribute toward standardized assessment and reporting of HCC-suspect lesions in high-risk patients. ESCULAP shows significantly higher diagnostic accuracy, sensitivity and negative predictive value with no loss of specificity compared with CEUS-LI-RADS. Both algorithms have an excellent PPV. Arterial hyperenhancement is the key feature for the diagnosis of HCC with CEUS. Washout should not be a necessary prerequisite for the diagnosis of definite HCC. CEUS-LI-RADS in its current version is inferior to ESCULAP for the noninvasive diagnosis of HCC. There are two ways to improve CEUS-LI-RADS: firstly, combination of the categories LR-4 and LR-5 for the diagnosis of definite HCC, and secondly, use of subtotal infiltration of a liver lobe as an additional feature.

Combination of acoustic radiation force impulse imaging, serological indexes and contrast-enhanced ultrasound for diagnosis of liver lesions

AIM

To assess the value of combined acoustic radiation force impulse (ARFI) imaging, serological indexes and contrast-enhanced ultrasound (CEUS) in distinguishing between benign and malignant liver lesions.

METHODS

Patients with liver lesions treated at our hospital were included in this study. The lesions were divided into either a malignant tumor group or a benign tumor group according to pathological or radiological findings. ARFI quantitative detection, serological testing and CEUS quantitative detection were performed and compared. A comparative analysis of the measured indexes was performed between these groups. Receiver operating characteristic (ROC) curves were constructed to compare the diagnostic accuracy of ARFI imaging, serological indexes and CEUS, alone or in different combinations, in identifying benign and malignant liver lesions.

RESULTS

A total of 112 liver lesions in 43 patients were included, of which 78 were malignant and 34 were benign. Shear wave velocity (SWV) value, serum alpha-fetoprotein (AFP) content and enhancement rate were significantly higher in the malignant tumor group than in the benign tumor group (2.39 ± 1.20 m/s vs 1.50 ± 0.49 m/s, 18.02 ± 5.01 ng/mL vs 15.96 ± 4.33 ng/mL, 2.14 ± 0.21 dB/s vs 2.01 ± 0.31 dB/s; P < 0.05). The ROC curve analysis revealed that the areas under the curves (AUCs) of SWV value alone, AFP content alone, enhancement rate alone, SWV value + AFP content, SWV value + enhancement rate, AFP content + enhancement rate and SWV value + AFP content + enhancement rate were 85.1%, 72.1%, 74.5%, 88.3%, 90.4%, 82.0% and 92.3%, respectively. The AUC of SWV value + AFP content + enhancement rate was higher than those of SWV value + AFP content and SWV value + enhancement rate, and significantly higher than those of any single parameter or the combination of any two of parameters.

CONCLUSION

The combination of SWV, AFP and enhancement rate had better diagnostic performance in distinguishing between benign and malignant liver lesions than the use of any single parameter or the combination of any two of parameters. It is expected that this would provide a tool for the differential diagnosis of benign and malignant liver lesions.

Asia-Pacific clinical practice guidelines on the management of hepatocellular carcinoma: a 2017 update

There is great geographical variation in the distribution of hepatocellular carcinoma (HCC), with the majority of all cases worldwide found in the Asia–Pacific region, where HCC is one of the leading public health problems. Since the “Toward Revision of the Asian Pacific Association for the Study of the Liver (APASL) HCC Guidelines” meeting held at the 25th annual conference of the APASL in Tokyo, the newest guidelines for the treatment of HCC published by the APASL has been discussed. This latest guidelines recommend evidence-based management of HCC and are considered suitable for universal use in the Asia–Pacific region, which has a diversity of medical environments.

Imaging of autoimmune hepatitis and overlap syndromes

Autoimmune hepatitis (AIH) is an uncommon, chronic inflammatory, and relapsing liver disease of unknown origin that may lead to liver cirrhosis, hepatocellular carcinoma, liver transplantation, or death. AIH occurs in all age groups and races but can frequently manifest as acute fulminant hepatitis. Clinical presentation of AIH can have features similar to primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC), and these diseases may coexist leading to overlap syndromes. Although histological diagnosis is necessary, imaging features often can demonstrate characteristics that may be helpful to distinguish these diseases. Imaging features of AIH are those of chronic liver disease, and imaging plays important role in detection of complications and ruling out other possible causes of chronic liver disease. Emerging techniques such as elastography provide non-invasive options for diagnosis of significant fibrosis and cirrhosis during clinical follow-up as well as assessment of response to treatment. In this study, we will describe imaging findings in AIH and overlap syndromes.

Noninvasive Markers to Assess Liver Fibrosis

Chronic liver disease represents a major public health problem, accounting for significant morbidity and mortality worldwide. Their prognosis and management greatly depends on the amount and progression of liver fibrosis with time and the risk of development of cirrhosis. Historically, liver biopsy was considered to be the gold standard for the detection of fibrosis. Nevertheless, liver biopsy is an invasive procedure that has limitations in terms of patient acceptance, risk-benefit ratio, cost-effectiveness, and its availability in various geographic regions. Moreover, it is a questionable gold standard due to significant sampling error and intraobserver and interobserver variability. These limitations have led to the development of noninvasive techniques for assessing the presence and the degree of liver fibrosis. This review aims to revise the most recent data from the literature about noninvasive methods useful in the evaluation of liver fibrosis.

Latest developments in precancerous lesions of hepatocellular carcinoma

Hepatocarcinogenesis in human chronic liver diseases is a multi-step process in which hepatic precancerous lesions progress into early hepatocellular carcinoma (HCC) and progressed HCC, and the close surveillance and treatment of these lesions will help improve the survival rates of patients with HCC. The rapid development and extensive application of imaging technology have facilitated the discovery of nodular lesions of ambiguous significance, such as dysplastic nodules. Further investigations showed that these nodules may be hepatic precancerous lesions, and they often appear in patients with liver cirrhosis. Although the morphology of these nodules is not sufficient to support a diagnosis of malignant tumor, these nodules are closely correlated with the occurrence of HCC, as indicated by long-term follow-up studies. In recent years, the rapid development and wide application of pathology, molecular genetics and imaging technology have elucidated the characteristics of precancerous lesions. Based on our extensive review of the relevant literature, this article focuses on evidence indicating that high-grade dysplastic nodules are more likely to transform into HCC than low-grade dysplastic nodules based on clinical, pathological, molecular genetic and radiological assessments. In addition, evidence supporting the precancerous nature of large cell change in hepatitis B virus-related HCC is discussed.

Imaging findings of mimickers of hepatocellular carcinoma

Radiological imaging plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC) as the noninvasive diagnosis of HCC in high-risk patients by typical imaging findings alone is widely adopted in major practice guidelines for HCC. While imaging techniques have markedly improved in detecting small liver lesions, they often detect incidental benign liver lesions and non-hepatocellular malignancy that can be misdiagnosed as HCC. The most common mimicker of HCC in cirrhotic liver is nontumorous arterioportal shunts that are seen as focal hypervascular liver lesions on dynamic contrast-enhanced cross-sectional imaging. Rapidly enhancing hemangiomas can be easily misdiagnosed as HCC especially on MR imaging with liver-specific contrast agent. Focal inflammatory liver lesions mimic HCC by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging. It is important to recognize the suggestive imaging findings for intrahepatic cholangiocarcinoma (CC) as the management of CC is largely different from that of HCC. There are other benign mimickers of HCC such as angiomyolipomas and focal nodular hyperplasia-like nodules. Recognition of their typical imaging findings can reduce false-positive HCC diagnosis.

Intensity-Based Assessment of Microbubble-Enhanced Ultrasonography: Phase-Related Diagnostic Ability for Cellular Differentiation of Hepatocellular Carcinoma

This prospective study aimed to elucidate the effect of phase-related quantitative parameters of contrast-enhanced ultrasound (CEUS) with perflubutane microbubble agent to assess the cellular differentiation of hepatocellular carcinoma (HCC). Intensity was analyzed in 94 lesions (19.4 ± 4.9 mm, 86 patients), 47 well-differentiated HCCs (wHCCs) and 47 moderately-differentiated HCCs (mHCCs): I(e) (early phase) = I(te) (tumor) - I(le) (liver), I(p) (post-vascular phase) = I(tp) (tumor) - I(lp) (liver), I(ep) = I(e) - I(p). The area under the receiver operating characteristic curve with the best cutoff value (I(e), 13.2, I(p), -4.5, I(ep), 21.3) for discriminating between wHCC and mHCC was 0.6922 for Ie, 0.7680 for Ip and 0.7925 for Iep, which indicated a significantly greater ability to differentiate between wHCC and mHCC compared with visual/qualitative assessment (early phase, 0.6170, p = 0.04; post-vascular phase, 0.6702, p = 0.01; both phases, 0.7021, p = 0.04). In conclusion, I(ep) was found to have the highest diagnostic ability, suggesting it is a promising parameter for the cellular differentiation of HCCs with CEUS.

Diagnostic and therapeutic management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an increasing health problem, representing the second cause of cancer-related mortality worldwide. The major risk factor for HCC is cirrhosis. In developing countries, viral hepatitis represent the major risk factor, whereas in developed countries, the epidemic of obesity, diabetes and nonalcoholic steatohepatitis contribute to the observed increase in HCC incidence. Cirrhotic patients are recommended to undergo HCC surveillance by abdominal ultrasounds at 6-mo intervals. The current diagnostic algorithms for HCC rely on typical radiological hallmarks in dynamic contrast-enhanced imaging, while the use of α-fetoprotein as an independent tool for HCC surveillance is not recommended by current guidelines due to its low sensitivity and specificity. Early diagnosis is crucial for curative treatments. Surgical resection, radiofrequency ablation and liver transplantation are considered the cornerstones of curative therapy, while for patients with more advanced HCC recommended options include sorafenib and trans-arterial chemo-embolization. A multidisciplinary team, consisting of hepatologists, surgeons, radiologists, oncologists and pathologists, is fundamental for a correct management. In this paper, we review the diagnostic and therapeutic management of HCC, with a focus on the most recent evidences and recommendations from guidelines.

Clinical Value of Contrast-Enhanced Ultrasound in Diagnosis of Hyperechoic Liver Lesions

Background

The purpose of this study was to investigate the values of contrast-enhanced ultrasound (CEUS) in the diagnosis and differential diagnosis of hyperechoic liver lesions.

Material/Methods

The CEUS findings of 102 patients with hyperechoic liver lesions identified by 2-dimensional ultrasound in the Affiliated Tumor Hospital of Guangxi Medical University were reviewed and analyzed.

Results

A total of 135 lesions were analyzed, of which malignant lesions were found in 72 patients and benign lesions in 63, with a CEUS accuracy rate of 91.11%, which was significantly higher than that of conventional ultrasound (74.81%; P<0.05).

Conclusions

CEUS can improve the accuracy rate of ultrasonography in the diagnosis and differential diagnosis of hyperechoic liver lesions.

Contrast-Enhanced Ultrasound of Focal Liver Lesions

OBJECTIVE

The purpose of this article is to discuss the use of contrast-enhanced ultra-sound (CEUS) in focal liver lesions.

CONCLUSION

Focal liver lesions are usually detected incidentally during abdominal ultrasound. The injection of microbubble ultrasound contrast agents improves the characterization of focal liver lesions that are indeterminate on conventional ultrasound. The use of CEUS is recommended in official guidelines and suggested as a second diagnostic step after ultrasound detection of indeterminate focal liver lesions to immediately establish the diagnosis, especially for benign liver lesions, such as hemangiomas, avoiding further and more expensive examinations.

Contrast-enhanced ultrasound in differentiating malignant from benign portal vein thrombosis in hepatocellular carcinoma

Portal vein thrombosis (PVT) may occur in liver cirrhosis patients. Malignant PVT is a common complication in cirrhotic patients with concomitant hepatocellular carcinoma (HCC) and, in some cases, it may be even the initial sign of an undetected HCC. Detection of malignant PVT in a patient with liver cirrhosis heavily affects the therapeutic strategy. Gray-scale ultrasound (US) is widely unreliable for differentiating benign and malignant thrombi. Although effective for this differential diagnosis, fine-needle biopsy remains an invasive technique. Sensitivity of color-doppler US in detection of malignant thrombi is highly dependent on the size of the thrombus. Contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance (MRI) can be useful to assess the nature of portal thrombus, while limited data are currently available about the role of positron emission tomography (PET) and PET-CT. In contrast with CT, MRI, PET, and PET-CT, contrast-enhanced ultrasound (CEUS) is a fast, effective, well tolerated and cheap technique, that can be performed even in the same session in which the thrombus has been detected. CEUS can be performed bedside and can be available also in transplanted patients. Moreover, CT and MRI only yield a snapshot analysis during contrast diffusion, while CEUS allows for a continuous real-time imaging of the microcirculation that lasts several minutes, so that the whole arterial phase and the late parenchymal phase of the contrast diffusion can be analyzed continuously by real-time US scanning. Continuous real-time monitoring of contrast diffusion entails an easy detection of thrombus maximum enhancement. Moreover, continuous quantitative analyses of enhancement (wash in - wash out studies) by CEUS during contrast diffusion is nowadays available in most CEUS machines, thus giving a more sophisticated and accurate evaluation of the contrast distribution and an increased confidence in diagnosis in difficult cases. In conclusion, CEUS is a very reliable technique with a high intrinsic sensitivity for portal vein patency assessment. More expensive and sophisticated techniques (i.e., CT, MRI, PET, and PET-CT) should only be indicated in undetermined cases at CEUS.

Local ablation therapy with contrast-enhanced ultrasonography for hepatocellular carcinoma: a practical review

A successful program for local ablation therapy for hepatocellular carcinoma (HCC) requires extensive imaging support for diagnosis and localization of HCC, imaging guidance for the ablation procedures, and post-treatment monitoring. Contrast-enhanced ultrasonography (CEUS) has several advantages over computed tomography/magnetic resonance imaging (CT/MRI), including real-time imaging capability, sensitive detection of arterial-phase hypervascularity and washout, no renal excretion, no ionizing radiation, repeatability, excellent patient compliance, and relatively low cost. CEUS is useful for image guidance for isoechoic lesions. While contrast-enhanced CT/MRI is the standard method for the diagnosis of HCC and post-ablation monitoring, CEUS is useful when CT/MRI findings are indeterminate or CT/MRI is contraindicated. This article provides a practical review of the role of CEUS in imaging algorithms for pre- and post-ablation therapy for HCC.

A novel simple noninvasive index to predict renal transplant acute rejection by contrast-enhanced ultrasonography

PURPOSE

This study aimed to evaluate the application of quantitative contrast-enhanced ultrasonography (CEUS) in the assessment of renal allograft dysfunction and to establish a new noninvasive index to predict acute rejection (AR).

METHODS

Fifty-seven renal transplant recipients were enrolled in this prospective study. Before renal allograft biopsy, CEUS examinations were performed.The biopsy results proved 23 cases of AR (AR group), 10 cases of acute tubular necrosis (ATN group), and 24 with normal evolution (stable group). Contrast-enhanced ultrasonography parameters including rising time (RT), time to peak (TTP), and the delta-time among regions of interest (ΔRT and ΔTTP) were analyzed.

RESULTS

In the AR group, RT and TTP of interlobar artery and medulla (RTi, RTm, TTPi, and TTPm) as well as ΔRT and ΔTTP between medulla and cortex (ΔRTm-c and ΔTTPm-c) were significantly higher compared with those in the stable group. RTm and TTPm as well as ΔRTm-c and ΔTTPm-c were remarkably higher compared with those in the ATN group. ΔRTm-c and estimated glomerular filtration rate (eGFR) were identified as independent predictors by multivariate analysis (P = 0.008 and P = 0.024). On the basis of the multivariate analysis results and area under the receiver operating characteristic curves of individual markers, we constructed a new simple index, P = -0.587 + 0.286 ×ΔRTm-c − 0.028 × eGFR; new index = e(P)/(1 + e(P)), to discriminate AR, which had better area under the receiver operating characteristic curves than eGFR or individual CEUS parameters.

CONCLUSION

Contrast-enhanced ultrasonography parameters are reliable markers for differentiating the perfusion status of transplanted kidneys. Furthermore, the new simple index can easily predictAR with a high degree of accuracy.

Contrast-enhanced ultrasound in the diagnosis of patients suspected of having active Crohn's disease: meta-analysis

This meta-analysis was aimed at assessing the performance of oral/microbubble contrast-enhanced ultrasound (CEUS) in the detection of active Crohn's disease (CD). A literature search of PubMed, Medline, the China National Knowledge Infrastructure and the Cochrane Library was conducted. Published articles that evaluated the diagnostic potency of CEUS in CD were included in the study. A total of eight articles, which included 428 patients, were finally analyzed. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and area under the curve were calculated to examine the diagnostic accuracy of CEUS. The pooled sensitivity and specificity of CEUS for active CD were 93% (95% confidence interval: 89%-95%) and 87% (81%-91%), respectively. The summary diagnostic odds ratio was 80.35 (30.93-208.73), and the area under the curve was 0.9633. In conclusion, this meta-analysis pooled results from previous studies to evaluate the accuracy of CEUS in the detection of CD. We found that CEUS has high accuracy in the detection of active CD using endoscopy/biopsy or clinical index as the reference standard. In the future, CEUS may also be widely used in other diseases, reducing the necessity for invasive diagnostic procedure.