Contrast-enhanced guided endoscopic ultrasound procedures

Contrast-enhanced endoscopic ultrasound(CH-EUS)can overcome the limi-tations of endoscopic ultrasound-guided acquisition by identifying microvessels inside inhomogeneous tumours and improving the characterization of these tumours.Despite the initial enthusiasm that oriented needle sampling under CH-EUS guidance could provide better diagnostic yield in pancreatic solid lesions,further studies did not confirm the supplementary values in cases of tissue acquisition guided by CH-EUS.This review details the knowledge based on the available data on contrast-guided procedures.The indications for CH-EUS tissue acquisition include isoechoic EUS lesions with poor visible delineation where CH-EUS can differentiate the lesion vascularisation from the surrounding parenchyma and also the mural nodules within biliopancreatic cystic lesions,which occur in select cases.Additionally,the roles of CH-EUS-guided therapy in patients whose pancreatic fluid collections or bile ducts that have an echogenic content have indications for drainage,and patients who have nonvisualized vessels that need to be highlighted via Doppler EUS are presented.Another indication is represented if there is a need for an immediate assessment of the post-radiofrequency ablation of pancreatic neuroendocrine tumours,in which case CH-EUS can be used to reveal the incomplete tumour destruction.

Survival Analysis of Patients Undergoing Intraoperative Contrast-enhanced Ultrasound in the Surgical Treatment of Malignant Glioma

Objective:Complete resection of malignant gliomas is often challenging.Our previous study indicated that intraoperative contrast-enhanced ultrasound(ICEUS)could aid in the detection of residual tumor remnants and the total removal of brain lesions.This study aimed to investigate the survival rates of patients undergoing resection with or without the use of ICEUS and to assess the impact of ICEUS on the prognosis of patients with malignant glioma.Methods:A total of 64 patients diagnosed with malignant glioma(WHO grade HI and IV)who underwent surgery between 2012 and 2018 were included.Among them,29 patients received ICEUS.The effects of ICEUS on overall survival(OS)and progression-free survival(PFS)of patients were evaluated.A quantitative analysis was performed to compare ICEUS parameters between gliomas and the surrounding tissues.Results:The ICEUS group showed better survival rates both in OS and PFS than the control group.The univariate analysis revealed that age,pathology and ICEUS were significant prognostic factors for PFS,with only age being a significant prognostic factor for OS.In multivariate analysis,age and ICEUS were significant prognostic factors for both OS and PFS.The quantitative analysis showed that the intensity and transit time of microbubbles reaching the tumors were significantly different from those of microbubbles reaching the surrounding tissue.Conclusion:ICEUS facilitates the identification of residual tumors.Age and ICEUS are prognostic factors for malignant glioma surgery,and use of ICEUS offers a better prognosis for patients with malignant glioma.

Evaluating the efficacy of percutaneous puncture biopsy guided by contrast-enhanced ultrasound for peripheral pulmonary lesions

BACKGROUND The incidence and mortality of lung cancer have increased annually.Accurate diagnosis can help improve therapeutic efficacy of interventions and prognosis.Percutaneous lung biopsy is a reliable method for the clinical diagnosis of lung cancer.Ultrasound-guided percutaneous lung biopsy technology has been widely promoted and applied in recent years.AIM To investigate the diagnostic value of contrast-enhanced ultrasound(CEUS)-guided percutaneous biopsy in peripheral pulmonary lesions.METHODS We retrospectively collected data on 237 patients with peripheral thoracic focal lesions who underwent puncture biopsy at Wuxi People’s Hospital.The patients were randomly divided into two groups:The CEUS-guided before lesion puncture group(contrast group)and conventional ultrasound-guided group(control group).Analyze the diagnostic efficacy of the puncture biopsy,impact of tumor size,and number of puncture needles and complications were analyzed and compared between the two groups.RESULTS Accurate pathological results were obtained for 92.83%(220/237)of peripheral lung lesions during the first biopsy,with an accuracy rate of 95.8%(113/118)in the contrast group and 89.9%(107/119)in the control group.The difference in the area under the curve(AUC)between the contrast and the control groups was not statistically significant(0.952 vs 0.902,respectively;P>0.05).However,when the lesion diameter≥5 cm,the diagnostic AUC of the contrast group was higher than that of the control group(0.952 vs 0.902,respectively;P<0.05).In addition,the average number of puncture needles in the contrast group was lower than that in the control group(2.58±0.53 vs 2.90±0.56,respectively;P<0.05).CONCLUSION CEUS guidance can enhance the efficiency of puncture biopsy of peripheral pulmonary lesions,especially for lesions with a diameter≥5 cm.Therefore,CEUS guidance has high clinical diagnostic value in puncture biopsy of peripheral focal lung lesions.

Clinical application of oral contrast-enhanced ultrasound in evaluating the preoperative T staging of gastric cancer

BACKGROUND Oral contrast-enhanced ultrasound(OCEUS)is widely used in the noninvasive diagnosis and screening of gastric cancer(GC)in China.AIM To investigate the clinical application of OCEUS in evaluating the preoperative T staging of gastric cancer.METHODS OCEUS was performed before the operation,and standard ultrasound images were retained.The depth of infiltration of GC(T-stage)was evaluated according to the American Joint Committee on Cancer 8th edition of the tumor-nodemetastasis staging criteria.Finally,with postoperative pathological staging as the gold standard reference,the sensitivity,specificity,negative predictive value,positive predictive value,and diagnostic value of OCEUS T staging were evaluated.RESULTS OCEUS achieved diagnostic accuracy rates of 76.6%(T1a),69.6%(T1b),62.7%(T2),60.8%(T3),88.0%(T4a),and 88.7%(T4b),with an average of 75.5%.Ultrasonic T staging sensitivity exceeded 62%,aside from T1b at 40.3%,while specificity was over 91%,except for T3 with 83.5%.The Youden index was above 60%,with T1b and T2 being exceptions.OCEUS T staging corresponded closely with pathology in T4b(kappa>0.75)and moderately in T1a,T1b,T2,T3,and T4a(kappa 0.40-0.75),registering a concordance rate exceeding 84%.CONCLUSION OCEUS was effective,reliable,and accurate in diagnosing the preoperative T staging of GC.As a noninvasive diagnostic technique,OCEUS merits clinical popularization.

Ultrasomics in liver cancer: Developing a radiomics model for differentiating intrahepatic cholangiocarcinoma from hepatocellular carcinoma using contrast-enhanced ultrasound

BACKGROUND Hepatocellular carcinoma(HCC)and intrahepatic cholangiocarcinoma(ICC)represent the predominant histological types of primary liver cancer,comprising over 99%of cases.Given their differing biological behaviors,prognoses,and treatment strategies,accurately differentiating between HCC and ICC is crucial for effective clinical management.Radiomics,an emerging image processing technology,can automatically extract various quantitative image features that may elude the human eye.Reports on the application of ultrasound(US)-based radiomics methods in distinguishing HCC from ICC are limited.METHODS In our retrospective study,we included a total of 280 patients who were diagnosed with ICC(n=140)and HCC(n=140)between 1999 and 2019.These patients were divided into training(n=224)and testing(n=56)groups for analysis.US images and relevant clinical characteristics were collected.We utilized the XGBoost method to extract and select radiomics features and further employed a random forest algorithm to establish ultrasomics models.We compared the diagnostic performances of these ultrasomics models with that of radiologists.RESULTS Four distinct ultrasomics models were constructed,with the number of selected features varying between models:13 features for the US model;15 for the contrast-enhanced ultrasound(CEUS)model;13 for the combined US+CEUS model;and 21 for the US+CEUS+clinical data model.The US+CEUS+clinical data model yielded the highest area under the receiver operating characteristic curve(AUC)among all models,achieving an AUC of 0.973 in the validation cohort and 0.971 in the test cohort.This performance exceeded even the most experienced radiologist(AUC=0.964).The AUC for the US+CEUS model(training cohort AUC=0.964,test cohort AUC=0.955)was significantly higher than that of the US model alone(training cohort AUC=0.822,test cohort AUC=0.816).This finding underscored the significant benefit of incorporating CEUS information in accurately distin-guishing ICC from HCC.CONCLUSION We developed a radiomics diagnostic model based on CEUS images capable of quickly distinguishing HCC from ICC,which outperformed experienced radiologists.

Ultrasound,contrast-enhanced ultrasound and pyelonephritis:A narrative review

Acute pyelonephritis(APN)is a bacterial infection resulting in kidney inflammation,typically arising as a complication of an ascending urinary tract infection that ascends from the bladder to the kidneys.Clinical diagnosis is generally based on clinical and laboratory findings.Recent guidelines recommend not performing diagnostic imaging unless a complicated APN is suspected or the infection affects high-risk patients such as the elderly,immunocompromised individuals,or diabetics.Contrast-enhanced ultrasound(CEUS)is a valuable tool in both the diagnosis and follow-up of APN.It aids in distinguishing small simple nephritic involvement from abscess complications and monitoring their evolution over time during antibiotic therapy.Given its lack of ionizing radiation and nephrotoxicity,CEUS is a valid diagnostic modality for approaching and monitoring pyelonephritis,improving early identification and characterization of inflammatory lesions.This review aims to summarize the main evidence on the use of ultrasound and CEUS in the diagnosis of APN and its follow-up.

Gastrointestinal contrast-enhanced ultrasonography for diagnosis and treatment of peptic ulcer in children

BACKGROUND The detection rate of peptic ulcer in children is improving,with development of diagnostic procedures.Gastroscopy is the gold standard for the diagnosis of peptic ulcer,but it is an invasive procedure.Gastrointestinal contrast-enhanced ultrasonography(CEUS)has the advantages of being painless,noninvasive,nonradioactive,easy to use,and safe.AIM To investigate the clinical value of CEUS for diagnosis and treatment of peptic ulcer in children.METHODS We investigated 43 children with digestive tract symptoms in our hospital from January 2021 to June 2022.All children were examined by routine ultrasound,gastrointestinal CEUS,and gastroscopy.The pathological results of gastroscopy were taken as the gold standard.Routine ultrasonography was performed before gastrointestinal CEUS.Conventional ultrasound showed the thickness of the gastroduodenal wall,gastric peristalsis,and the adjacent organs and tissues around the abdominal cavity.Gastrointestinal CEUS recorded the thickness of the gastroduodenal wall;the size,location and shape of the ulcer;gastric peristalsis;and adjacent organs and tissues around the abdominal cavity.The results of routine ultrasound and gastrointestinal ultrasound were compared with those of gastroscopy to evaluate the diagnostic results and coincidence rate of routine ultrasound and gastrointestinal CEUS.All children received informed consent from their guardians for CEUS.This study was reviewed and approved by the hospital medical ethics committee.RESULTS Among the 43 children,17(15 male,2 female)were diagnosed with peptic ulcer by gastroscopy.There were 26 children with nonpeptic ulcer.There were eight cases of peptic ulcer and 35 of nonpeptic ulcer diagnosed by conventional ultrasound.The diagnostic coincidence rate of peptic ulcer in children diagnosed by conventional ultrasound was 79.1%(34/43),which was significantly different from that of gastroscopy(P=0.033).It indicates that the coincidence rate of gastrointestinal contrast-enhanced ultrasound and gastroscope is low.Fifteen cases of peptic ulcer and 28 of nonpeptic ulcer were diagnosed by CEUS.The diagnostic coincidence rate of peptic ulcer in children was 95.3%(41/43).There was no significant difference between CEUS and gastroscopy(P=0.655).It indicates that the coincidence rate of gastrointestinal contrast-enhanced ultrasound and gastroscope is high.CONCLUSION Gastrointestinal CEUS has a high coincidence rate in the diagnosis of peptic ulcer in children,and can be used as a preliminary examination method.

Value of contrast-enhanced ultrasound in deep angiomyxoma using a biplane transrectal probe:A case report

BACKGROUND Deep angiomyxoma(DAM)is a very rare tumor type.Magnetic resonance imaging(MRI)is considered the best imaging modality for diagnosing DAM.Computed tomography(CT)is used mainly to assess the invasion range of DAM.The value of ultrasonography in the diagnosis of DAM is still controversial.Through a literature review,we summarized the current state of ultrasonic examination for DAM and reported for the first time the contrast-enhanced ultrasound(CEUS)features of DAM seen using a biplane transrectal probe.CASE SUMMARY A 37-year-old woman presented with a sacrococcygeal mass that had gradually increased in size over the previous 6 mo.MRI and CT examinations failed to allow a definite diagnosis to be made.Transperineal core needle biopsy(CNB)guided by transrectal ultrasound and CEUS was suggested after a multidisciplinary discussion.Grayscale ultrasound of the lesion showed a layered appearance with alternating hyperechoic and hypoechoic patterns.Transrectal CEUS showed a laminated distribution of the contrast agent that was consistent with the layered appearance of the tumor on grayscale ultrasound.We performed transperineal CNB of the enhanced area inside the tumor under transrectal CEUS guidance and finally made a definitive diagnosis of DAM through histopathology.The patient underwent laparoscopic-assisted transabdominal surgery combined with transperineal surgery for large pelvic tumor resection and pelvic floor peritoneal reconstruction.No recurrence or metastasis was found at the ninemonth follow-up.CONCLUSION Transrectal CEUS can show the layered perfusion characteristics of the contrast agent,guiding subsequent transperineal CNB of the enhanced area within the DAM.

Quantitative evaluation of colorectal tumour vasculature using contrast-enhanced ultrasound:Correlation with angiogenesis and prognostic significance

BACKGROUND Ultrasound is a vital tool for the diagnosis and management of colorectal cancer(CRC).Contrast-enhanced ultrasound(CEUS)is a non-invasive,safe,and cost-effective method for evaluating tumour blood vessels,that play a crucial role in tumour growth and progression.AIM To explore CEUS’s role in the quantitative evaluation of CRC blood vessels and their correlation with angiogenesis markers and prognosis.METHODS This study prospectively enrolled 100 patients with CRC confirmed by histo-pathology.All patients received preoperative CEUS examinations.Quantitative parameters,such as peak intensity(PI),time to peak(TTP),and area under the curve(AUC),were derived from time-intensity curve(TIC)analysis.Tumour tissue samples were obtained during surgery and examined immunohistochem-ically to assess the expression of angiogenesis markers,including vascular endo-thelial growth factor(VEGF)and microvessel density(MVD).The correlation between CEUS parameters,angiogenesis markers,and clinicopathological features was evaluated using appropriate statistical tests.RESULTS Quantitative CEUS parameters(PI,TTP,and AUC)showed significant correlations with VEGF expression(P<0.001)and MVD(P<0.001),indicating a strong link between tumour blood vessels and angiogenesis.Increased PI,reduced TTP,and expanded AUC values were significantly related to higher tumour stage(P<0.001),lymph node metastasis(P<0.001),and distant metastasis(P<0.001).Furthermore,these parameters were recognized as independent predictors of overall survival and disease-free survival in multivariate analysis(P<0.001).CONCLUSION CEUS has a high potential in guiding treatment planning and predicting patient outcomes.However,more com-prehensive,multicentre studies are required to validate the clinical utility of CEUS in CRC management.

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 biliary system:Potential uses and indications

Conventional ultrasound(US)is the first-line imaging investigation for biliary diseases.However,it is lack of the ability to depict the microcirculation of some lesions which may lead to failure in diagnosis for some biliary diseases.The use of contrast-enhanced US(CEUS)has reached the field of bile duct disease in recent years and promising results have been achieved.In this review,the methodology,image interpretation,enhancement pattern,clinical usefulness,and indications for CEUS in the biliary system are summarized.CEUS may be indicated in the biliary system under the following circumstances:(1)Where there is a need to make a characterization of intrahepatic cholangiocarcinoma(ICC);(2)For differentiation diagnosis between ICC and other tumors(i.e.hepatocellular carcinoma or liver metastasis)or infectious diseases;(3)For differentiation diagnosis between biliary cystadenoma and biliary cystadenocarcinoma;(4)To detect malignant change in Caroli’s disease;(5)To depict the extent of Klatskin’s tumor with greater clarity;(6)To make a distinction between gallbladder cholesterol polyp,adenoma and polypoid cancer;(7)To make a distinction between chronic cholecystitis with thickened wall and gallbladder cancer;(8)For differentiation diagnosis between motionless sludge and gallbladder cancer;(9)For differentiation diagnosis between common bile duct cancer and sludge or stone without acoustic shadowing;and(10)In patients who are suspected of having a drop of their percutaneous transhepatic cholangiodrainage tube,US contrast agent can be administered to through the tube detect the site of the tube.

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.

Value of contrast-enhanced ultrasound combined with elastography in evaluating cervical lymph node metastasis in papillary thyroid carcinoma

BACKGROUND Cervical lymph node metastasis in papillary thyroid carcinoma(PTC) affects the treatment and prognosis of patients. Ultrasound is a common imaging method for detecting cervical lymph nodes in PTC patients; however, it is not accurate in determining lymph node metastasis.AIM To evaluate the value of contrast-enhanced ultrasound combined with elastography in evaluating cervical lymph node metastasis in PTC.METHODS A total of 94 patients with PTC were recruited. According to pathological results,lymph nodes were divided into two groups: metastatic group(n = 50) and reactive group(n = 63). The routine ultrasound findings, contrast-enhanced ultrasound and elastography data were recorded and compared. Logistic regression was used to generate predictive probability distributions for the diagnosis of lymph node metastasis with different indicators. Receiver operating characteristic curve analysis was used to test the efficacy of contrast-enhanced ultrasound combined with elastography based on routine ultrasound in evaluating PTC cervical lymph node metastasis.RESULTS The ratio of long diameter/short diameter(L/S) ≤ 2, irregular marginal morphology, missing lymphatic portal, peripheral or mixed blood flow distribution, peak intensity(PI), non-uniform contrast distribution and elasticity score in the metastatic group were significantly higher than those in the reactive group(P < 0.05). L/S ratio, missing lymphatic portal, PI and elasticity score had a significant influence on the occurrence of PTC cervical lymph node metastasis(P< 0.05). Furthermore, the area under the curve(AUC) for lymph node metastasis diagnosed using the combination of PI ratio, elasticity score, missing lymphatic portal and LS was 0.936, which was significantly higher than the AUC for PI ratio alone. The difference was statistically significant(P < 0.05). The fitting equation for the combined diagnosis was logit(P) =-12.341 + 1.482 × L/S ratio + 3.529 ×missing lymphatic portal + 0.392 × PI + 3.288 × elasticity score.CONCLUSION Based on the gray-scale ultrasound, the combination of contrast-enhanced ultrasound and elastography can accurately assess PTC cervical lymph node metastasis.

Contrast-enhanced ultrasound:Improving the preoperative staging of hepatocellular carcinoma and guiding individual treatment

AIM: To investigate the clinical role of contrast-enhanced ultrasound (CEUS) combined with contrast-enhanced computed tomography (CE-CT) or magnetic resonance imaging to improve the preoperative staging of hepatocellular carcinoma (HCC) and guide surgical decision-making. METHODS: Sixty-nine patients who underwent liver resection for HCC in our center were enrolled prospectively in the study. CEUS and CE-CT/MRI were performed before surgery. Intraoperative ultrasound (IOUS) was carried out after liver mobilization. Lesions depicted by each imaging modality were counted and mapped. To investigate the impact of tumor size on the study, we divided the patients into two groups, the 'Smaller group'(S-group, <= 5 cm in diameter) and the 'Largergroup' (L-group, > 5 cm in diameter). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CE-CT/MRI, CEUS, IOUS, CEUS+CE-CT/MRI and the tumor node metastasis staging of tumors were calculated and compared. Changes in the surgical strategy as a result of CEUS and IOUS were analyzed. RESULTS: One hundred and twenty-seven nodules, comprising 94 HCCs confirmed by histopathology and 33 benign lesions confirmed by histopathology and follow-up, were identified in 69 patients. The overall diagnostic sensitivity rates of CE-CT/MRI, CEUS, IOUS and CEUS+ CE-CT/MRI were 78.7%, 89.4%, 89.4% and 89.4%, respectively. There was a significant difference between CEUS + CE-CT/MRI and CE-CT/MRI (P = 0.046). Combining CEUS with CT or MRI increased, the diagnostic specificity compared with CT/MRI, CEUS and IOUS, and this difference was statistically significant (100%, 72.7%, 97.0%, and 69.7%, P = 0.004, P = 0.002, P = 0.002, respectively). The diagnostic accuracy was significantly higher for CEUS + CT/MRI compared with CT/MRI (92.1% vs 77.2%, P = 0.001). The TNM staging of tumors based on CEUS + CE-CT/MRI approximated to the final pathological TNM staging (P = 0.977). There was a significant difference in the accuracy of TNM staging when comparing CEUS + CECT/MRI with CE-CT/MRI (P = 0.002). Before surgery, strategies were changed in 15.9% (11/69) of patients as a result of CEUS. Finally, only 5.7% (4/69) of surgical strategies were changed because of IOUS findings. In the S-group, CEUS revealed 12 false positive lesions, including seven false positive lesions that were diagnosed by preoperative imaging examinations and five by IOUS. In contrast, in the L-group, IUOS revealed eight new malignant lesions; six of these lesions were true HCCs that were also identified by preoperative CEUS. CONCLUSION: CEUS combined with CT or MRI improves the accuracy of preoperative staging for hepatocellular carcinoma and may help to guide individualized treatment for patients with HCC. CEUS may better identify non-malignant lesions in patients with small tumors and discover new malignant lesions in patients with large tumors. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

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.

Review of dynamic contrast-enhanced ultrasound guidance in ablation therapy for hepatocellular carcinoma

Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly def ined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in diffi cult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an effi cient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.

Three-dimensional endoanal ultrasound for diagnosis of perianal fistulas: reliable and objective technique

AIM: To evaluate accuracy of three-dimensional endoanal ultrasound(3D-EAUS) as compared to 2D-EAUS and physical examination(PE) in diagnosis of perianal fistulas and correlate with intraoperative findings. METHODS: A prospective observational consecutive study was performed with patients included over a two years period. All patients were studied and operated on by the Colorectal Unit surgeons. The inclusion criteria were patients over 18, diagnosed with a criptoglandular perianal fistula. The PE, 2D-EAUS and 3D-EAUS was performed preoperatively by the same colorectal surgeon at the outpatient clinic prior to surgery and the fistula anatomy was defined and they were classified in intersphincteric, high or low transsphincteric, suprasphincteric and extrasphincteric. Special attention was paid to the presence of a secondary tract, the location of the internal opening(IO) and the site of external opening. The results of these different examinations were compared to the intraoperative findings. Data regarding location of the IO, primary tract, secondary tract, and the presence of abscesses or cavities wasanalysed.RESULTS: Seventy patients with a mean age of 47years(range 21-77), 51 male were included. Low transsphincteric fistulas were the most frequent type found(33, 47.1%) followed by high transsphincteric(24,34.3%) and intersphincteric fistulas(13, 18.6%). There are no significant differences between the number of IO diagnosed by the different techniques employed and surgery(P > 0.05) and, there is a good concordance between intraoperative findings and the 2D-EAUS(k= 0.67) and 3D-EAUS(k = 0.75) for the diagnosis of the primary tract. The ROC curves for the diagnosis of transsphincteric fistulas show that both ultrasound techniques are adequate for the diagnosis of low transsphincteric fistulas, 3D-EAUS is superior for the diagnosis of high transsphincteric fistulas and PE is weak for the diagnosis of both types.CONCLUSION: 3D-EAUS shows a higher accuracy than 2D-EAUS for assessing height of primary tract in transsphincteric fistulas. Both techniques show a good concordance with intraoperative finding for diagnosis of primary tracts.

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.

Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions

The extensive use of imaging techniques in differential diagnosis of abdominal conditions and screening of hepatocellular carcinoma in patients with chronic hepatic diseases,has led to an important increase in identification of focal liver lesions.The development of contrastenhanced ultrasound(CEUS) opens a new window in the diagnosis and follow-up of these lesions.This technique offers obvious advantages over the computed tomography and magnetic resonance,without a decrease in its sensitivity and specificity.The new second generation contrast agents,due to their intravascular distribution,allow a continuous evaluation of the enhancement pattern,which is crucial in characterization of liver lesions.The dual blood supply in the liver shows three different phases,namely arterial,portal and late phases.The enhancement during portal and late phases can give important information about the lesion's behavior.Each liver lesion has a different enhancement pattern that makes possible an accurate approach to their diagnosis.The role of emerging techniques as a contrastenhanced three-dimensional US is also discussed.In this article,the advantages,indications and technique employed during CEUS and the different enhancement patterns of most benign and malignant focal liver lesions are discussed.

Contrast-enhanced ultrasound:The evolving applications

Contrast-enhanced ultrasound(CEUS)is a major breakthrough for ultrasound imaging in recent years.By using a microbubble contrast agent and contrast-specific imaging software,CEUS is able to depict the microand macro-circulation of the targeted organ,which in turn leads to improved performance in diagnosis.Due to the special dual blood supply system in the liver,CEUS is particularly suitable for liver imaging.It is evident that CEUS facilitates improvement for characterization of focal liver lesions(FLLs),detection of liver malignancy,guidance for interventional procedures,and evaluation of treatment response after local therapies.CEUS has been demonstrated to be equal to contrast-enhanced computed tomography or magnetic resonance imaging for the characterization of FLLs.In addition,the applicability of CEUS has expanded to non-liver structures such as gallbladder,bile duct,pancreas,kidney,spleen,breast,thyroid,and prostate.The usefulness of CEUS in these applications is confirmed by extensive literature production.Novel applications include detecting bleeding sites and hematomas in patients with abdominal trauma,guiding percutaneous injection therapy and therefore achieving the goal of using interventional ultrasonography in managing splenic trauma,assessing the activity of Crohn’s disease,and detecting suspected endoleaks after endovascular abdominal aneurysm repair.Contrast-enhanced intraoperative ultrasound(US)and intracavitary use of CEUS have been developed and clinically studied.The potential use of CEUS involves sentinel lymph node detection,drug or gene delivery,and molecular imaging.In conclusion,the advent of CEUS has greatly enhanced the usefulness of US and even changed the status of US in clinical practice.The application of CEUS in the clinic is continuously evolving and it is expected that its use will be expanded further in the future.