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.

Is it a normal phenomenon for pediatric patients to have brain leptomeningeal contrast enhancement on 3-tesla magnetic resonance imaging?

Determining whether sevoflurane sedation in children leads to“pseudo”prominent leptomeningeal contrast enhancement(pLMCE)on 3 Tesla magnetic resonance imaging will help reduce overdiagnosis by radiologists and clarify the pathophysiological changes of pLMCE.

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.

Optimization of three-dimensional boiling enhancement structure at evaporation surface for high power light emitting diode

A theoretical model of phase change heat sink was established in terms of thermal resistance network. The influence of different parameters on the thermal resistance was analyzed and the crucial impact factors were determined. Subsequently, the forming methods including ploughing-extrusion and stamping method of boiling enhancement structure at evaporation surface were investigated, upon which three-dimensional microgroove structure was fabricated to improve the efficiency of evaporation. Moreover, the crucial parameters related to the fabrication of miniaturized phase change heat sink were optimized. The heat transfer performance of the heat sink was tested. Results show that the developed phase change heat sink has excellent heat transfer performance and is suitable for high power LED applications.

An improved detail enhancement algorithm based on difference curvature and contrast field

The gradient image is always sensitive to noise in image detail enhancement. To overcome this shortage, an improved detail enhancement algorithm based on difference curvature and contrast field is proposed. Firstly, the difference curvature is utilized to determine the amplification coefficient instead of the gradient. This new amplification function of the difference curvature takes more neighboring points into account, it is therefore not sensitive to noise. Secondly, the contrast field is nonlinearly amplified according to the new amplification coefficient. And then, with the enhanced contrast field, we construct the energy functional. Finally, the enhanced image is reconstructed by the variational method. Experimental results of standard testing image and industrial X-ray image show that the proposed algorithm can perform well on increasing contrast and sharpening edges of images while suppressing noise at the same time.

Does sevoflurane sedation in pediatric patients lead to“pseudo”leptomeningeal enhancement in the brain on 3 Tesla magnetic resonance imaging?

BACKGROUND Prominent leptomeningeal contrast enhancement(LMCE)in the brain is observed in some pediatric patients during sedation for imaging.However,based on clinical history and cerebrospinal fluid analysis,the patients are not acutely ill and do not exhibit meningeal signs.Our study determined whether sevoflurane inhalation in pediatric patients led to this pattern of‘pseudo’LMCE(pLMCE)on 3 Tesla magnetic resonance imaging(MRI).AIM To highlight the significance of pLMCE in pediatric patients undergoing enhanced brain MRI under sedation to avoid misinterpretation in reports.METHODS A retrospective cross-sectional evaluation of pediatric patients between 0-8 years of age was conducted.The patients underwent enhanced brain MRI under inhaled sevoflurane.The LMCE grade was determined by two radiologists,and interobserver variability of the grade was calculated using Cohen’s kappa.The LMCE grade was correlated with duration of sedation,age and weight using the Spearman rho rank correlation.RESULTS A total of 63 patients were included.Fourteen(22.2%)cases showed mild LMCE,48(76.1%)cases showed moderate LMCE,and 1 case(1.6%)showed severe LMCE.We found substantial agreement between the two radiologists in detection of pLMCE on post-contrast T1 imaging(kappa value=0.61;P<0.001).Additionally,we found statistically significant inverse and moderate correlations between patient weight and age.There was no correlation between duration of sedation and pLMCE.CONCLUSION pLMCE is relatively common on post-contrast spin echo T1-weighted MRI of pediatric patients sedated by sevoflurane due to their fragile and immature vasculature.It should not be misinterpreted for meningeal pathology.Knowing pertinent clinical history of the child is an essential prerequisite to avoid radiological overcalling and the subsequent burden of additional investigations.

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 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.

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.

Application of contrast-enhanced intraoperative ultrasonography in the decision-making about hepatocellular carcinoma operation

AIM:To evaluate the detection and differentiation ability of contrast-enhanced intraoperative ultrasonography(CE-IOUS) in hepatocellular carcinoma(HCC) operations.METHODS:Clinical data of 50 HCC patients were retrospective analyzed.The sensitivity,specificity,false negative and false positive rates of contrast enhanced magnetic resonance imaging(CE-MRI),IOUS and CEIOUS were calculated and compared.Surgical strategy changes due to CE-IOUS were analyzed.RESULTS:Lesions detected by CE-MRI,IOUS and CEIOUS were 60,97 and 85 respectively.The sensitivity,specificity,false negative rate,false positive rate of CEMRI were 98.2%,98.6%,98.6%,60.0%,respectively;for IOUS were 50.0%,90.9%,1.8%,1.4%,respectively;and for CE-IOUS were 1.4%,40.0%,50.0%,9.1%,respectively.The operation strategy of 9(9/50,18.0%) cases was changed according to the results of CE-IOUS.CONCLUSION:Compared with CE-MRI,CE-IOUS performs better in detection and differentiation of small metastasis and regenerative nodules.It plays an important role in the decision-making of HCC operation.

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 of renal masses

Contrast enhanced ultrasound(CEUS) has gained clinical importance over the last years for the characterization of hepatic masses.Its role in extrahepatic indications has been investigated repeatedly but has been less comprehensively studied.Currently more than 50% of renal masses are incidentally diagnosed,mostly by B-mode ultrasound.The method of choice for characterization of renal lesions is contrast enhanced computed tomography(CECT).In the case of cystic lesions CECT refers to the Bosniak classification for cystic lesions to assess the risk of malignant behavior.The majority of masses are renal cell carcinoma,but the exact proportion is controversial.Disadvantages of CECT are a significant risk for patients with impaired renal function,allergic reactions and hyperthyroidism due to iodinated contrast agents.Several studies concerning CEUS for the characterization of both solid and cystic renal lesions have been published,but prospective multicenter studies are missing,the presented data being mainly descriptive.The aim of the this manuscript is to review the current literature for CEUS in renal masses,to summarize the available data and focus on possible concepts for studies in the future.

Contrast-enhanced endoscopic ultrasound in discrimination between focal pancreatitis and pancreatic cancer

AIM： To evaluate the contrast-enhanced endosonography as a method of differentiating inflammation from pancreatic carcinoma based on perfusion characteristics of microvessels. METHODS： In 86 patients with suspected chronic pancreatitis （age： 62± 12 years; sex： f/m 38/48）, pancreatic lesions were examined by conventional endo- scopic B-mode, power Doppler ultrasound and contrastenhanced power mode （Hitachi EUB 525, SonoVue, 2.4 mL, Bracco） using the following criteria for malignant lesions： no detectable vascularisation using conventional power Doppler scanning, irregular appearance of arterial vessels over a short distance using SonoVue contrastenhanced technique and no detectable venous vessels inside the lesion. A malignant lesion was assumed if all criteria were detectable [gold standard endoscopic ultrasound （EUS）-guided fine needle aspiration cytology, operation]. The criteria of chronic pancreatitis without neoplasia were defined as no detectable vascularisation before injection of SonoVue, regular appearance of vessels over a distance of at least 20 mm after injection of SonoVue and detection of arterial and venous vessels. RESULTS： The sensitivity and specifidty of conventional EUS were 73.2% and 83.3% respectively for pancreatic cancer. The sensitivity of contrast-enhanced EUS increased to 91.1% in 51 of 56 patients with malignant pancreatic lesion and the specificity increased to 93.3% in 28 of 30 patients with chronic inflammatory pancreatic disease.CONCLUSION： Contrast-enhanced endoscopic ultrasound improves the differentiation between chronic pancreatitis and pancreatic carcinoma.

Contrast-enhanced ultrasonography for the evaluation of liver fibrosis after biliary obstruction

AIM:To investigate perfusion change in contrastenhanced ultrasonography(CEUS) to evaluate liver fibrosis based on biliary obstruction using an animal model.METHODS:New Zealand white rabbits(3-4 kg) underwent bile duct ligation to form a biliary obstruction model.We performed liver CEUS and laboratory tests on the day before the operation(day 0) and every 7 postoperative days until the rabbits were sacrificed.After CEUS,signal intensity of liver parenchyma with a time-intensity curve was analyzed.Perfusion parameters were automatically calculated from regionof-interests,including peak signal intensity,mean transit time,area under the curve and time to peak.Histological grades of liver fibrosis were assessed according to the Metavir score system immediately after sacrifice.Generalized estimating equations were used to analyze the association between liver fibrosis grades and perfusion parameters for statistical analysis.The perfusion parameters were measured on the last day and the difference between day 0 and the last day were evaluated.RESULTS:From the nine rabbits,histological grades of liver fibrosis were grade 1 in one rabbit,grade 2 and 3 in three rabbits each,and grade 4 in two rabbits.Among the four CEUS parameters,only the peak signal intensity measured on the last day demonstrated a significant association with liver fibrosis grades(OR =1.392,95%CI:1.114-1.741,P =0.004).The difference in peak signal intensity between day 0 and the last dayalso demonstrated an association with liver fibrosis(OR =1.191,95%CI:0.999-1.419,P =0.051).The other parameters tested,including mean transit time,area under the curve,and time to peak,showed no significant correlation with liver fibrosis grades.CONCLUSION:This animal study demonstrates that CEUS can be used to evaluate liver fibrosis from biliary obstruction using peak signal intensity as a parameter.

Renal blood perfusion in GK rats using targeted contrast enhanced ultrasonography

Objective: To explore application of targeted contrast enhanced ultrasonography in diagnosis of early stage vascular endothelial injury and diabetic nephropathy. Methods: Targeted Sono VueTM microbubble was prepared by attaching anti-TM monoclonal antibody to the surface of ordinary micro-bubble Sono Vue by biotin-avidin bridge method and ultrasonic instrument was used to evaluate the developing situation of targeted microbubble in vitro. Twenty 12-week-old male GK rats and 20 Wistar rats were enrolled in this study, and were randomly divided into targeted angiography group and ordinary angiography group. Targeted microbubbles Sono VueTM or general microbubble Sono Vue were rapidly injected to the rats via tail vein; the developing situation of the two contrast agents in rats kidneys was dynamically observed. Time intensity curve was used to analyse rat kidney perfusion characteristics in different groups. Results: Targeted ultrasound microbubble Sono Vue-TM was successfully constructed, and it could be used to develop an external image. Targeted microbubbles Sono Vue-TM enabled clear development of experimental rat kidney. Time intensity curve shapes of rat kidney of the two groups showed as single apex with steep ascending and slowly descending branch. Compared with the control group, the rising slope of the GK rat renal cortex, medulla in targeted angiography group increased(P<0.05); the peak intensity of medulla increased(P<0.05), and the total area under the curve of medulla increased(P<0.05). Compared with control group, the ascending branch of the GK rat in renal cortex, medulla in ordinary angiography group increased(P<0.05). The peak intensity of the curve increased(P<0.05), and the total area under the curve increased(P<0.05). Compared with the ordinary angiography group, the peak of GK rat medullacurve in targeted angiography group intensity increased(P<0.05), and the total area under the curve increased(P<0.05). Conclusions: Targeted microbubbles Sono VueTM can make a clear development of experimental rat kidney, its stable performance meet the requirement of ultrasonic observation time limit, and it can reflect early changes of blood perfusion in GK rat kindey.

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.

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 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.

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.