Contrast ultrasound in hepatocellular carcinoma at a tertiary liver center: First Indian experience

AIM: To assess the role of contrast enhanced ultrasonography in evaluation of hepatocellular carcinoma (HCC) at the first Indian tertiary liver center. METHODS: Retrospective analysis of contrast enhanced ultrasound (CEUS) examinations over 24 mo for diagnosis, surveillance, characterization and follow up of 50 patients in the context of HCC was performed. The source and indication of referrals, change in referral rate, accuracy and usefulness of CEUS in a tertiary liver center equipped with a 64 slice dual energy computer tomography (CT) and 3 tesla magnetic resonance imaging (MRI) were studied. Sonovue (BR1, Bracco, Italy, a second generation contrast agent) was used for contrast US studies. Contrast enhanced CT/MRI or both were performed in all patients. The findings were taken as a baseline reference and correlation was done with respect to contrast US. Contrast enhanced MRI was performed using hepatocyte specific gadobenate dimeglumine (Gd-BOPTA). Iomeron (400 mg; w/v) was used for dynamic CT examinations. RESULTS: About 20 (40%) of the examinations were referred from clinicians for characterization of a mass from previous imaging. About 15 (30%) were performed for surveillance in chronic liver disease; 5 (10%) examinations were performed for monitoring lesions after radiofrequency ablation (RFA); 3 (6%) were post trans-arterial chemoembolization (TACE) assessments and 3 (6%) were patients with h/o iodinated contrast allergy. About 2(4%) were performed on hemodynamically unstable patients in the intensive care with raised alpha fetoprotein and 2(4%) patients were claustrophobic. The number of patients referred from clinicians steadily increased from 12 in the first 12 mo of the study to 38 in the last 12 mo. CEUS was able to diagnose 88% of positive cases of HCC as per reference standards. In the surveillance group, specificity was 53.3% vs 100% by CT/MRI. Post RFA and TACE specificity of lesion characterization by CEUS was 100% in single/large mass assessment, similar to CT/MRI. For non HCC lesions such as regenerative and dysplastic nodules, the specificity was 50% vs 90% by CT/MRI. The positive role of CEUS in imaging spectrum of HCC included a provisional urgent diagnosis of an incidentally detected mass. It further led to a decrease in time for further management. A confident diagnosis on CEUS was possible in cases of characterization of an indeterminate mass, in situations where the patient was unfit for CT/MRI, was allergic to iodinated contrast or had claustrophobia, etc.CEUS was also cost effective, radiation free and an easy modality for monitoring post RFA or TACE lesions. CONCLUSION: CEUS is a valuable augmentation to the practice of ultrasonography, and an irreplaceable modality for confounding cases and interpretation of indeterminate lesions in imaging of HCC.

Dynamic contrast enhanced ultrasound in differential diagnosis of hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND Non-invasive differential diagnosis between hepatocellular carcinoma(HCC)and other liver cancer(i.e.cholangiocarcinoma or metastasis)is highly challenging and definitive diagnosis still relies on histological exam.The patterns of enhancement and wash-out of liver nodules can be used to stratify the risk of malignancy only in cirrhotic patients and HCC frequently shows atypical features.Dynamic contrast-enhanced ultrasound(DCEUS)with standardized software could help to overcome these obstacles,providing functional and quantitative parameters and potentially improving accuracy in the evaluation of tumor perfusion.AIM To explore clinical evidence regarding the application of DCEUS in the differential diagnosis of liver nodules.METHODS A comprehensive literature search of clinical studies was performed to identify the parameters of DCEUS that could relate to histological diagnosis.In accordance with the study protocol,a qualitative and quantitative analysis of the evidence was planned.RESULTS Rise time was significantly higher in HCC patients with a standardized mean difference(SMD)of 0.83(95%CI:0.48-1.18).Similarly,other statistically significant parameters were mean transit time local with a SMD of 0.73(95%CI:0.20-1.27),peak enhancement with a SMD of 0.37(95%CI:0.03-0.70),area wash-in area under the curve with a SMD of 0.47(95%CI:0.13-0.81),wash-out area under the curve with a SMD of 0.55(95%CI:0.21-0.89)and wash-in and wash-out area under the curve with SMD of 0.51(95%CI:0.17-0.85).SMD resulted not significant in fall time and wash-in rate,but the latter presented a trend towards greater values in HCC compared to intrahepatic cholangiocarcinoma.CONCLUSION DCEUS could improve non-invasive diagnosis of HCC,leading to less liver biopsy and early treatment.This quantitative analysis needs to be applied on larger cohorts to confirm these preliminary results.

Evaluation of the Therapeutic Effect of Contrast-Enhanced Ultrasound on Different Types of Knee Osteoarthritis in the Elderly

Objective: To evaluate the curative effect of the Traditional Chinese Medicine (TCM) external therapy on knee osteoarthritis patients with different TCM constitutions using musculoskeletal ultrasonography and contrast-enhanced ultrasonography, and to explore the application value of contrast-enhanced ultrasonography in knee joint diseases. Methods: A total of 57 patients diagnosed with knee osteoarthritis in Shaanxi University of Traditional Chinese Medicine from December 2019 to May 2021 were collected, and they were divided into qi stagnation and blood stasis type group (23 cases) and cold-dampness obstruction type group (34 cases) according to the traditional Chinese medicine method. All patients were given acupuncture combined with TCM fumigation and washing. All patients underwent musculoskeletal ultrasonography and contrast-enhanced ultrasonography before and after treatment, observed and recorded relevant data, and compared the treatment effects between the two groups. Results: 85.96% (49/57) of knee osteoarthritis (KOA) patients had suprapatellar bursa effusion, 42.1% (24/57) had iliotibial band bursae effusion, some of which had poor sound transmission, and thickened synovium was seen in most effusions, 33.33% (19/57) had osteophyte formation. Compared with before treatment, the depth of suprapatellar sac effusion in the Qi stagnation and blood stasis type group decreased after treatment (P Conclusion: Musculoskeletal contrast-enhanced ultrasonography was used to quantitatively evaluate the efficacy of TCM external therapy on KOA for different TCM constitutions. Dynamic observation of synovial lesions of knee osteoarthritis provides a valuable imaging method for evaluating the efficacy of traditional Chinese medicine.

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

Contrast-enhanced ultrasound(CEUS)using microbubble contrast agents are useful for the diagnosis of the nodules in liver cirrhosis.CEUS can be used as a problem-solving method for indeterminate nodules on computed tomography(CT)or magnetic resonance imaging(MRI)or as an initial diagnostic test for small newly detected liver nodules.CEUS has unique advantages over CT and MRI including no renal excretion of contrast,real-time imaging capability,and purely intravascular contrast.Hepatocellular carcinoma(HCC)is characterized by arterial-phase hypervascularity and later washout(negative enhancement).Benign nodules such as regenerative nodules or dysplastic nodules are usually isoechoic or slightly hypoechoic in the arterial phase and isoechoic in the late phase.However,there are occasional HCC lesions with atypical enhancement including hypovascular HCC and hypervascular HCC without washout.Cholangiocarcinomas are infrequently detected during HCC surveillance and mostly show rimlike or diffuse hypervascularity followed by rapid washout.Hemangiomas are often found at HCC surveillance and are easily diagnosed by CEUS.CEUS can be effectively used in the diagnostic work-up of small nodules detected at HCC surveillance.CEUS is also useful to differentiate malignant and benign venous thrombosis and to guide and monitor the local ablation therapy for HCC.

Decreased accumulation of ultrasound contrast in the liver of nonalcoholic steatohepatitis rat model

AIM:To investigate the diagnosis of nonalcoholic steatohepatitis(NASH) using contrast ultrasonography in the NASH rat model.METHODS:The liver in methionine choline-deficient diet(MCDD) rats,a NASH model constructed by feeding an MCDD,was examined by contrast ultrasonography at weeks 2,4,8,12 and 16,with late phase images of contrast ultrasonography(Kupffer imaging) in which contrast enhancement was achieved by incorporation of a contrast agent by Kupffer cells(KCs),and images were compared to those in rats taking a regular chow.RESULTS:Decrease in contrast enhancement was observed first in MCDD rats at week 2.KCs were counted based on immunohistochemistry,but their numbers were not reduced and it was assumed that attenuation of contrast enhancement was attributable to reduced phagocytic activity of the KCs.CONCLUSION:It is suggested that clinical application of contrast ultrasonography may be valuable for noninvasive diagnosis of NASH.

Liver metastases:Contrast-enhanced ultrasound compared with computed tomography and magnetic resonance

The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound(US)for several applications,especially for the detection of metastases.In particular,contrast enhanced ultrasonography(CEUS)allows the display of the parenchymal microvasculature,enabling the study and visualization of the enhancement patterns of liver lesions in real time and in a continuous manner in all vascular phases,which is similar to contrast-enhanced computed tomography(CT)and contrast-enhanced magnetic resonance imaging.Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-US.Furthermore,studies have shown that CEUS yields sensitivities comparable to CT.In this review,we describe the state of the art of CEUS for detecting colorectal liver metastases,the imaging features,the literature reports of metastases in CEUS as well as its technique,its clinical role and its potential applications.Additionally,the updated international consensus panel guidelines are reported in this review with the inherent limitations of this technique and best practice experiences.

Effect of contrast-enhanced ultrasound on differential diagnosis of intrahepatic cholangiocarcinoma and arterial phase enhanced hepatic inflammatory lesions

Objective: To investigate differential diagnosis between intrahepatic cholangiocarcinoma (ICC) and arterial phase enhanced hepatic inflammatory lesions in patients without liver cirrhosis using contrast-enhanced ultrasound (CEUS). Methods: ICC and hepatic inflammatory lesions cases with CEUS and pathological diagnosis between Sep 2013 and Oct 2016 were investigated retrospectively. Imaging features of conventional ultrasound and CEUS were analyzed. The parameters of time intensity curve (TIC), including the arrival time, peak intensity (PI) in the lesions, the starting time for washout, and the intensity difference at 3 min (Delta I-3) after contrast agent infection between the lesion and the liver parenchyma, were compared between ICC and hepatic inflammatory lesions. Results: Twenty-five ICC and fifteen inflammatory patients were included in this study. Seventeen ICC (68.0%) and two inflammatory cases (13.3%) showed bile duct dilatation on conventional ultrasound. Using CEUS, three ICC cases (12.0%) were misdiagnosed as inflammatory lesions and three inflammatory lesions (20.0%) as ICC; two ICC (8.0%) and one inflammatory case (6.7%) could not be made definite diagnosis. Washout started at 34.5 +/- 3.5 s and 61.5 +/- 12.9 s for ICC and inflammatory lesions respectively (P < 0.001). The intensity difference between lesion and liver parenchyma at 3 min after contrast agent injection was 10.8 +/- 3.1 dB in ICC and 4.2 +/- 2.3 dB in inflammatory group (P < 0.001). The sensitivity and specificity differentiating ICC and inflammatory lesions were 76% and 87% if the cut-off value of the intensity difference was 7.7 dB. Conclusions: Combined with TIC analysis, and particularly with the characteristic of the early-starting and obvious washout in ICC, CEUS can be useful in differential diagnosis between hepatic inflammatory lesions and ICC.

Contrast-enhanced ultrasound evaluation of hepatic microvascular changes in liver diseases

AIM： To assess if software assisted-contrast-enhanced ultrasonography （CEUS） provides reproducible perfu- sion parameters of hepatic parenchyma in patients af- fected by chronic liver disease. METHODS： Forty patients with chronic viral liver dis- ease, with （n = 20） or without （n = 20） cirrhosis, and 10 healthy subjects underwent CEUS and video re- cordings of each examination were then analysed with Esaote＇s Qontrast software. CEUS dedicated software Qontrast was used to determine peak （the maximum signal intensity）, time to peak （TTP）, region of blood value （RBV） proportional to the area under the time- intensity curve, mean transit time （MTT） measured in seconds and region of blood flow （RBF）. RESULTS： Qontrast-assisted CEUS parameters dis- played high inter-observer reproducibility （κ： coefficients of 0.87 for MTT and 0.90 TTP）. When the region of in-terest included a main hepatic vein, Qontrast-calculated TTP was significantly shorter in cirrhotic patients （vs non-cirrhotics and healthy subjects） （71.0 ± 11.3 s vs 82.4±15.6 s, 86.3±20.3 s, P 〈 0.05）. MTIs in the patients with liver cirrhosis were significantly shorter than those of controls （111.9±22.0 s vs 139.4±39.8 s, P 〈 0.05）, but there was no significant difference between the cirrhotic and non-cirrhotic groups （111.9± 22.0 s vs 110.3 ±14.6 s）. Peak enhancement in the patients with liver cirrhosis was also higher than that observed in controls （23.9± 5.9 vs 18.9±7.1, P = 0.05）. There were no significant intergroup differences in the RBVs and RBFs. CONCLUSION： Qontrast-assisted CEUS revealed re- producible differences in liver perfusion parameters during the development of hepatic fibrogenesis.

Role of Contrast Enhanced Ultrasound in Radiofrequency Ablation of Metastatic Liver Carcinoma

Objective： To investigate the application of contrast enhanced ultrasound （CEUS） in planning and guiding for radiofrequency ablation （RFA） for metastatic liver carcinoma （MLC）. Methods： One hundred and thirty-five patients with clinically and pathologically diagnosed MLC （from gastrointestinal tumors） were included in the present study, and 104 of them had received CEUS prior to RFA to assess the number, size, shape, infiltration, location and enhancing features of the lesions. Among the 204 patients, 21 （20.1%） were excluded from RFA treatment due to too many lesions or large infiltrative range based on CEUS. The remaining 83 patients with 147 lesions underwent RFA （group A）. During the same period, other 32 patients with 202 lesions serving as control group were treated based on findings of conventional ultrasound without contrast （group B）. The patients underwent follow-up enhanced CT at the 1st month, and then every 3-6 months after RFA. The tumor was considered as early necrosis if no contrast enhancement was detected in the treated area on the CT scan at the 2st month. Results： In group A, 72 of 147 MLC lesions （48.9%） showed increased sizes on CEUS. Among them, 48 lesions （66.6%） appeared enlarged in arterial phase, and 24 （33.3%） showed enlarged hypoechoic area in parenchymal phase. CEUS showed total 61 additional lesions in 35 patients （42.2%） （ranged from 8 to 15 mm） compared with conventional ultrasound （US）, and 42 （68.8%） of them were visualized in parenchymal phase only. There were total 208 lesions in group A underwent RFA with CEUS planning, and the tumor necrosis rate was 94.2% （196/208）. In this group, local recurrence was found in 26 lesions （7.7%） during 3-42 months＇ following up, and new metastases were seen in 30 cases （36.2%）. For group B, the tumor necrosis rate was 86.3% （88/202）, local recurrence in 27 lesions （16.7%）, and new metastases in 13 cases （41.9%）. Tumor early necrosis and recurrence rates were significantly different between the two groups （P=0.018, P=0.016, respectively）. Conclusion： CEUS played an important role in RFA for liver metastases by candidate selecting and therapy planning, which helped to improve the outcome of the treatment.

Differentiation of atypical hepatic hemangioma from liver metastases: Diagnostic performance of a novel type of color contrast enhanced ultrasound

BACKGROUND In clinical practice,the diagnosis is sometimes difficult with contrast-enhanced ultrasound(CEUS)when the case has an atypical perfusion pattern.Color parametric imaging(CPI)is an analysis software for CEUS with better detection of temporal differences in CEUS imaging using arbitrary colors.It measures the differences in arrival time of the contrast agent in lesions so that the perfusion features of atypical hemangioma and colorectal cancer(CRC)liver metastasis can be distinguished.AIM To evaluate the role of a novel type of CPI of CEUS in the differential diagnosis of atypical hemangioma from liver metastases in patients with a history of CRC.METHODS From January 2016 to July 2018,42 patients including 20 cases of atypical hemangioma and 22 cases of liver metastases from CRC were enrolled.These patients had a mean age of 60.5±9.3 years(range:39-75 years).All patients received ultrasound,CEUS and CPI examinations.Resident and staff radiologists independently and retrospectively reviewed CEUS and CPI images.Two sets of criteria were assigned:(1)Routine CEUS alone;and(2)CEUS and CPI.The diagnostic sensitivity,specificity,accuracy and receiver operating characteristic(ROC)curve of resident and staff radiologists were analyzed.RESULTS The following CPI features were significantly different between liver hemangioma and liver metastases analyzed by staff and resident radiologists:Peripheral nodular enhancement(65%-70.0%vs 4.5%-13.6%,P<0.001,P=0.001),mosaic/chaotic enhancement(5%-10%vs 68.2%-63.6%,P<0.001,P<0.001)and feeding artery(20%vs 59.1%-54.5%,P=0.010,P=0.021).CPI imaging offered significant improvements in detection rates compared with routine CEUS in both resident and staff groups.By resident radiologists,the specificity and accuracy of CEUS+CPI were significantly increased compared with that of CEUS(77.3%vs 45.5%,P=0.030;78.6%vs 50.0%,P=0.006).In addition,the area under the curve(AUC)of CEUS+CPI was significantly higher than that of CEUS(0.803 vs 0.757,P=0.036).By staff radiologists,accuracy was improved in CEUS+CPI(81.0%vs 54.8%,P=0.010),whereas no significant differences in specificity and sensitivity were found(P=0.144,P=0.112).The AUC of CEUS+CPI was significantly higher than that of CEUS(0.890 vs 0.825,P=0.013)by staff radiologists.CONCLUSION Compared with routine CEUS,CPI could provide specific information on the hemodynamic features of liver lesions and help to differentiate atypical hemangioma from liver metastases in patients with CRC,even for senior radiologists.

Can contrast enhanced ultrasound differentiate intrahepatic cholangiocarcinoma from hepatocellular carcinoma?

BACKGROUND Hepatocellular carcinoma(HCC)and intrahepatic cholangiocarcinoma(ICC)differ in treatment and prognosis,warranting an effective differential diagnosis between them.The LR-M category in the contrast-enhanced ultrasound(CEUS)liver imaging reporting and data system(LI-RADS)was set up for lesions that are malignant but not specific to HCC.However,a substantial number of HCC cases in this category elevated the diagnostic challenge.AIM To investigate the possibility and efficacy of differentiating ICC from HCC classified in the LR-M category according to the CEUS LI-RADS.METHODS Patients with complete CEUS records together with pathologically confirmed ICC and LR-M HCC(HCC classified in the CEUS LI-RADS LR-M category)between January 2015 and October 2018 were included in this retrospective study.Each ICC was assigned a category as per the CEUS LI-RADS.The enhancement pattern,washout timing,and washout degree between the ICC and LR-M HCC were compared using theχ2 test.Logistic regression analysis was used for prediction of ICC.Receiver operating characteristic(ROC)curve analysis was used to investigate the possibility of LR-M criteria and serum tumor markers in differentiating ICC from LR-M HCC.RESULTS A total of 228 nodules(99 ICCs and 129 LR-M HCCs)in 228 patients were included.The mean sizes of ICC and LR-M HCC were 6.3±2.8 cm and 5.5±3.5 cm,respectively(P=0.03).Peripheral rim-like arterial phase hyperenhancement(APHE)was detected in 50.5%(50/99)of ICCs vs 16.3%(21/129)of LR-M HCCs(P<0.001).Early washout was found in 93.4%(93/99)of ICCs vs 96.1%(124/129)of LR-M HCCs(P>0.05).Marked washout was observed in 23.2%(23/99)of ICCs and 7.8%(10/129)of LR-M HCCs(P=0.002),while this feature did not show up alone either in ICC or LR-M HCC.Homogeneous hyperenhancement was detected in 15.2%(15/99)of ICCs and 37.2%(48/129)of LR-M HCCs(P<0.001).The logistic regression showed that rim APHE,carbohydrate antigen 19-9(CA 19-9),and alpha fetoprotein(AFP)had significant correlations with ICC(r=1.251,3.074,and-2.767,respectively;P<0.01).Rim APHE presented the best enhancement pattern for diagnosing ICC,with an area under the ROC curve(AUC)of 0.70,sensitivity of 70.4%,and specificity of 68.8%.When rim hyperenhancement was coupled with elevated CA 19-9 and normal AFP,the AUC and sensitivity improved to 0.82 and 100%,respectively,with specificity decreasing to 63.9%.CONCLUSION Rim APHE is a key predictor for differentiating ICC from LR-M HCC.Rim APHE plus elevated CA 19-9 and normal AFP is a strong predictor of ICC rather than LR-M HCC.Early washout and marked washout have limited value for the differentiation between the two entities.

Management of hepatocellular carcinoma: The role of contrast-enhanced ultrasound

Hepatocellular carcinoma(HCC)is the sixth most common neoplasm and the third cause of cancer death worldwide.Contrast enhanced ultrasound(CEUS)has been applied for more than ten years and plays increasingly important roles in the management of HCC.On the basis of the Guideline and Good Clinical Practice Recommendations for CEUS in the liver-update 2012and related literature about the management of HCC,we summarize the main roles and applications of CEUS in the management of HCC,including HCC surveillance,diagnosis,CEUS-guided treatment,treatment response evaluation and follow-up.The diagnostic algorithm for HCC is also suggested.Meanwhile,the comparisons between CEUS and contrast enhanced computed tomography/magnetic resonance imaging(CECT/CEMRI)in these areas are made.Although CEUS is subject to the same limitation as ordinary US and is inferior to CECT/CEMRI in some aspects,CEUS has proved to be of great value in the management of HCC with inher-ent advantages,such as sufficient high safety profile making it suitable for patients with renal failure or allergic to iodine,absence of radiation,easy reproducibility and high temporal resolution.The tremendous application of CEUS to the diagnosis and treatment of HCC provides more opportunities for patients with HCC diagnosed at different stages.

Role of contrast-enhanced ultrasound in follow-up assessment after ablation for hepatocellular carcinoma

AIM:To assess the usefulness of contrast-enhanced ultrasound (CEUS) during follow-up after percutaneous ablation therapy for hepatocellular carcinoma (HCC).METHODS:A total of 141 patients with HCCs who received percutaneous ablation therapy were assessed by paired follow-up CEUS and contrast-enhanced computed tomography (CECT).The follow-up scheme was designed prospectively and the intervals between CEUS and CECT examinations were less than 14 d.Both im-ages of follow-up CEUS and CECT were reviewed by radiologists.The ablated lesions were evaluated and classified as local tumor progression (LTP) and LTPfree.LTP was defined as regrowth of tumor inside or adjacent to the successfully treated nodule.The detected new intrahepatic recurrences were also evaluated and defined as presence of intrahepatic new foci.On CEUS and CECT,LTP and new intrahepatic recurrence both were displayed as typical enhancement pattern of HCC (i.e.,hyper-enhancing during the arterial phase and washout in the late phase).With CECT as the reference standard,the ability of CEUS in detecting LTP or new intrahepatic recurrence during follow-up was evaluated.RESULTS:During a follow-up period of 1-31 mo (median,4 mo),169 paired CEUS and CECT examinations were carried out for the 141 patients.For a total of 221 ablated lesions,266 comparisons between CEUS and CECT findings were performed.Thirty-three LTPs were detected on CEUS whereas 40 LTPs were detected on CECT,there was significant difference (P < 0.001).In comparison with CECT,the numbers of false positive and false negative LTPs detected on CEUS were 6 and 13,respectively;the sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) and overall accuracy of CEUS in detecting LTPs were 67.5%,97.4%,81.8%,94.4% and 92.3%,respectively.Meanwhile,131 new intrahepatic recurrent foci were detected on CEUS whereas 183 were detected on CECT,there was also significant difference (P < 0.05).In comparison with CECT,the numbers of false positive and false negative intrahepatic recurrences detected on CEUS were 13 and 65,respectively;the sensitivity,specificity,PPV,NPV and overall accuracy of CEUS in detecting new intrahepatic recurrent foci were 77.7%,92.0%,92.4%,76.7% and 84.0%,respectively.CONCLUSION:The sensitivity of CEUS in detecting LTP and new intrahepatic recurrence after percutaneous ablation therapy is relatively low in comparisonwith CECT.

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 avery 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.

Diagnostic value of contrast enhanced ultrasound for splenic artery complications following acute pancreatitis

AIM: To assess the value of contrast-enhanced ultrasound (CEUS) in diagnosing splenic artery complications (SACs) after acute pancreatitis (AP). METHODS: One hundred and eighteen patients with AP were enrolled in the study. All patients were examined by CEUS and contrast-enhanced computed tomography (CECT). CECT was accepted as a gold standard for the diagnosis of SACs in AP. The diagnostic accuracy of splenic CEUS and pancreatic CEUS was compared with that of CECT. Splenic infarction was the diagnostic criterion for splenic artery embolism and local dysperfusion of the splenic parenchyma was the diagnostic criterion for splenic arterial stenosis. The incidence of splenic sub-capsular hemorrhage, splenic artery aneurysms, and splenic rupture was all lower than that of SACs. RESULTS: Nine patients were diagnosed as having SACs after AP by CECT among the 118 patients. The patients with SACs were diagnosed with severe acute pancreatitis (SAP). Among them, 6 lesions were diagnosed as splenic artery embolism, 5 as splenic artery aneurysms, and 1 as splenic arterial stenosis. No lesion was diagnosed by pancreatic CEUS and 5 lesions were diagnosed by splenic CEUS. By splenic CEUS, 4 cases were diagnosed as splenic artery embolism and 1 as splenic arterial stenosis. The accuracy of splenic CEUS in diagnosis of SACs in SAP was 41.7% (5/12), which was higher than that of pancreatic CEUS (0%). CONCLUSION: Splenic CEUS is a supplementary method for pancreatic CEUS in AP patients, which can decrease missed diagnosis of SACs. (C) 2014 Baishideng Publishing Group Co., Limited. All rights reserved.

Application of contrast-enhanced ultrasound after livertransplantation:Current status and perspectives

Liver transplantation is an effective treatment for patients with end-stage liver disease. Accurate imaging evaluation of the transplanted patient is critical for ensuring that the limited donor liver is functioning appropriately. Ultrasound contrast agents(UCAs), in combination with contrastspecific imaging techniques, are increasingly accepted in clinical use for the assessment of the hepatic vasculature, bile ducts and liver parenchyma in pre-, intra- and posttransplant patients. We describe UCAs, their technical requirements, the recommended clinical indications, image interpretation and the limitations for contrastenhanced ultrasound applications in liver transplantation.

value of contrast-enhanced ultrasound in the differential diagnosis of gallbladder lesion

AIM To describe contrast-enhanced ultrasound(CEUS) features and evaluate differential diagnosis value of CEUS and conventional ultrasound for patients with benign and malignant gallbladder lesions. METHODS This study included 105 gallbladder lesions. Before surgical resection and pathological examination, conventional ultrasound and CEUS were performed to examine for lesions. Then, all the lesions were diagnosed as(1) benign,(2) probably benign,(3) probably malignant or(4) malignant using both conventional ultrasound and CEUS. The CEUS features of these gallbladder lesions were analyzed and diagnostic efficiency between conventional ultrasound and CEUS was compared.RESULTS There were total 17 cases of gallbladder cancer and 88 cases of benign lesion. Some gallbladder lesions had typical characteristics on CEUS(e.g., gallbladder adenomyomatosis had typical characteristics of small nonenhanced areas on CEUS). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CEUS were 94.1%, 95.5%, 80.0%, 98.8%and 95.2%, respectively. These were significantly higher than conventional ultrasound(82.4%, 89.8%, 60.9%, 96.3% and 88.6%, respectively). CEUS had an accuracy of 100% for gallbladder sludge and CEUS helped in differential diagnosis among gallbladder polyps, gallbladder adenoma and gallbladder cancer.CONCLUSION CEUS may provide more useful information and improve the diagnosis efficiency for the diagnosis of gallbladder lesions than conventional ultrasound.

Contrast-enhanced 3D ultrasound in the radiofrequency ablation of liver tumors

Liver metastases and hepatocellular carcinomas are two of the most common causes of cancer deaths in the world.Radiofrequency ablation(RFA) is a well recognized,effective and minimally invasive means of treating malignant hepatic tumors.This article describes the use of contrast-enhanced 3D ultrasound(CE-3DUS) in the staging,targeting and follow-up of patients with liver tumors undergoing RFA.In particular,its value in the management of large hepatic lesions will be illustrated.Current limitations of CE-3DUS and future developments in the technique will also be discussed.In summary,CE-3DUS is useful in the RFA of liver tumors with improved detection and display of occult lesions and recurrence,in the assessment of lesional geometry and orientation for a more accurate planning and guidance of multiple RFA needle electrodes in large tumors and in the evaluation of residual or recurrent disease within the immediate and/or subsequent follow-up periods.

Contrast-enhanced ultrasound of histologically proven hepatic epithelioid hemangioendothelioma

AIM: To analyze contrast-enhanced ultrasound(CEUS) features of histologically proven hepatic epithelioid hemangioendothelioma(HEHE) in comparison to other multilocular benign focal liver lesions(FLL).METHODS: Twenty-five patients with histologically proven HEHE and 45 patients with histologically proven multilocular benign FLL were retrospectively reviewed. Four radiologists assessed the CEUS enhancement pattern in consensus.RESULTS: HEHE manifested as a single(n = 3) or multinodular(n = 22) FLL. On CEUS, HEHE showed rim-like(18/25, 72%) or heterogeneous hyperenhancement(7/25, 28%) in the arterial phase and hypoenhancement(25/25, 100%) in the portal venous and late phases(PVLP), a sign of malignancy. Eighteen patients showed central unenhanced areas(18/25, 72%); in seven patients(7/25, 28%), more lesions were detected in the PVLP. In contrast, all patients with hemangioma and focal nodular hyperplasia showed hyperenhancement as the most distinctive feature(P < 0.01).CONCLUSION: CEUS allows for characterization of unequivocal FLL. By analyzing the hypoenhancement in the PVLP, CEUS can determine the malignant nature of HEHE.

Application of ultrasound contrast in identification and diagnosis of ocular spaceoccupying lesions

AIM: To analyze the application significance of ultrasound contrast agent in identification and diagnosis of ocular spaceoccupying lesions, and mainly analyze its advantages and problems. METHODS: Thirty-two representative literatures about the application of ultrasound contrast agent in diagnosis of spaceoccupying lesions at home and abroad were collected after focused on sorting the literature reporting the application of ultrasound contrast diagnostic technology in the diagnosis and identification of ocular spaceoccupying lesions in recent years. Its advantages and problems were retrospectively analyzed, and reasonable assessment on Existing problems was made and possible solutions to the problems were proposed. RESULTS: As a new imaging diagnostic technique, the contrast-enhanced ultrasound, which can enhance the display of tumor microcirculation vessels and improve the tumor's ultrasound diagnostic capability, was analyzed. Through sorting and comprehensively analyzing the collected literatures, the positive rate of ocular spaceoccupying lesion diagnosis could be significantly improved with ultrasound contrast technology. Thus, the vascular perfusion in normal tissues and lesions was reflected objectively. According to the lesion's perfusion characteristics of the contrast agent plus with the performance features of two-dimensional ultrasound, the ocular spaceoccupying lesions can be accurately diagnosed, and this could provide clinicians with reliable research basis in this field. CONCLUSION: Ultrasound contrast examination is a new testing method, and ultrasound contrast agent can significantly enhance the ultrasonic detection signal, clearly show the blood perfusion in vessels and tissues, increase the image contrast resolution, and improve the lesion's detection capability in the microcirculation perfusion level, especially its important value in the diagnosis of ocular tumor.