Assessment of metastatic liver disease in patients with primary extrahepatic tumors by contrast-enhanced sonography versus CT and MRI

AIM： To evaluate contrast-enhanced ultrasonography （CEUS） using SonoVue in the detection of liver metastases in patients with known extrahepatic primary tumors versus the combined gold standard comprising CT, MRI and clinical/histological data. METHODS： It is an international multicenter study, and there were 12 centres and 125 patients （64 males, 61 females, aged 59 ± 11 years） involved, with 102 patients per protocol. Primary tumors were colorectal in 35%, breast in 27%, pancreatic in 17% and others in 21%. CEUS using SonoVue was employed with a Iow-mechanical-index technique and contrast-specific software using Siemens Elegra, Philips HDI 5000 and Acuson Sequoia; continuous scanning for at least five minutes. RESULTS： CEUS with SonoVue increased significantly the number of focal liver lesions detected versus unenhanced sonography. In 31.4% of the patients, more lesions were found after contrast enhancement. The total numbers of lesions detected were comparable with CEUS （55）, triple-phase spiral CT （61） and HRI with a liverspecific contrast agent （53）. Accuracy of detection of metastatic disease （i.e. at least one metastatic lesion） was significantly higher for CEUS （91.2%） than for unenhanced sonography （81.4%） and was similar to that of triple-phase spiral CT （89.2 %）. In 53 patients whose CEUS examination was negative, a follow-up examination 3-6 months later confirmed the absence of metastatic lesions in 50 patients （94.4%）. CONCLUSION： CEUS is proved to be reliable in the detection of liver metastases in patients with known extrahepatic primary tumors and suspected liver lesions.

Artificial intelligence in medical imaging of the liver

Artificial intelligence(AI), particularly deep learning algorithms, is gaining extensive attention for its excellent performance in image-recognition tasks. They can automatically make a quantitative assessment of complex medical image characteristics and achieve an increased accuracy for diagnosis with higher efficiency. AI is widely used and getting increasingly popular in the medical imaging of the liver, including radiology, ultrasound, and nuclear medicine. AI can assist physicians to make more accurate and reproductive imaging diagnosis and also reduce the physicians' workload. This article illustrates basic technical knowledge about AI, including traditional machine learning and deep learning algorithms, especially convolutional neural networks, and their clinical application in the medical imaging of liver diseases, such as detecting and evaluating focal liver lesions, facilitating treatment, and predicting liver treatment response. We conclude that machine-assisted medical services will be a promising solution for future liver medical care. Lastly, we discuss the challenges and future directions of clinical application of deep learning techniques.

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.

New ultrasound techniques for lymph node evaluation

Conventional ultrasound(US)is the recommended imaging method for lymph node(LN)diseases with the advantages of high resolution,real time evaluation and relative low costs.Current indications of transcutaneous ultrasound and endoscopic ultrasound include the detection and characterization of lymph nodes and the guidance for LN biopsy.Recent advances in US technology,such as contrast enhanced ultrasound(CEUS),contrast enhanced endoscopic ultrasound(CE-EUS),and real time elastography show potential to improve the accuracy of US for the differential diagnosis of benign and malignant lymph nodes.In addition,CEUS and CE-EUS have been also used for the guidance of fine needle aspiration and assessment of treatment response.Complementary to size criteria,CEUS could also be used to evaluate response of tumor angiogenesis to anti-angiogenic therapies.In this paper we review current literature regarding evaluation of lymphadenopathy by new and innovative US techniques.

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.

Benign liver tumors in pediatric patients-Review with emphasis on imaging features

Benign hepatic tumors are commonly observed in adults,but rarely reported in children.The reasons for this remain speculative and the exact data concerning the incidence of these lesions are lacking.Benign hepatic tumors represent a diverse group of epithelial and mesenchymal tumors.In pediatric patients,most benign focal liver lesions are inborn and may grow like the rest of the body.Knowledge of pediatric liver diseases and their imaging appearances is essential in order to make an appropriate differential diagnosis.Selection of the appropriate imaging test is challenging,since it depends on a number of age-related factors.This paper will discuss the most frequently encountered benign liver tumors in children(infantile hepatic hemangioendothelioma,mesenchymal hamartoma,focal nodular hyperplasia,nodular regenerative hyperplasia,and hepatocellular adenoma),as well as a comparison to the current knowledge regarding such tumors in adult patients.The current emphasis is on imaging features,which are helpful not only for the initial diagnosis,but also for pre- and posttreatment evaluation and follow-up.In addition,future perspectives of contrast-enhanced ultrasound(CEUS) in pediatric patients are highlighted,with descriptions of enhancement patterns for each lesion being discussed.The role of advanced imaging tests such as CEUS and magnetic resonance imaging,which allow for non-invasive assessment of liver tumors,is of utmost importance in pediatric patients,especially when repeated imaging tests are needed and radiation exposure should be avoided.

Endoscopic ultrasonography-guided endoscopic treatment of pancreatic pseudocysts and walled-off necrosis:New technical developments

In the last decades,the treatment of pancreatic pseudocysts and necrosis occurring in the clinical context of acute and chronic pancreatitis has shifted towards minimally invasive endoscopic interventions.Surgical procedures can be avoided in many cases by using endoscopically placed,Endoscopic ultrasonography-guided techniques and drainages.Endoscopic ultrasound enables the placement of transmural plastic and metal stents or nasocystic tubes for the drainage of peripancreatic fluid collections.The development of selfexpanding metal stents and exchange free delivering systems have simplified the drainage of pancreatic fluid collections.This review will discuss available therapeutic techniques and new developments.

Endoscopic ultrasound elastography: current status and future perspectives

Elastography is a new ultrasound modality that provides images and measurements related to tissue stiffness. Endoscopic ultrasound(EUS) has played an important role in the diagnosis and management of numerous abdominal and mediastinal diseases. Elastography by means of EUS examination can assess the elasticity of tumors in the proximity of the digestive tract that are hard to reach with conventional transcutaneous ultrasound probes, such as pancreatic masses and mediastinal or abdominal lymph nodes, thus improving the diagnostic yield of the procedure. Results from previous studies have promised benefits for EUS elastography in the differential diagnosis of lymph nodes, as well as for assessing masses with pancreatic or gastrointestinal(GI) tract locations. It is important to mention that EUS elastography is not considered a modality that can replace biopsy. However, it may be a useful adjunct, improving the accuracy of EUSfine needle aspiration biopsy(EUS-FNAB) by selecting the most suspicious area to be targeted. Even more, it may be useful for guiding further clinical management when EUS-FNAB is negative or inconclusive. In the present paper we will discuss the current knowledge of EUS elastography, including the technical aspects, along with its applications in the differential diagnosis between benign and malignant solid pancreatic masses and lymph nodes, as well as its aid in the differentiation between normal pancreatic tissues and chronic pancreatitis. Moreover, the emergent indication and future perspectives are summarized, such as the benefit of EUS elastography in EUS-guided fine needle aspiration biopsy, and its uses for characterization of lesions in liver, biliary tract, adrenal glands and GI tract.

Artificial intelligence in breast ultrasound

Artificial intelligence(AI) is gaining extensive attention for its excellent performance in image-recognition tasks and increasingly applied in breast ultrasound. AI can conduct a quantitative assessment by recognizing imaging information automatically and make more accurate and reproductive imaging diagnosis. Breast cancer is the most commonly diagnosed cancer in women,severely threatening women's health, the early screening of which is closely related to the prognosis of patients. Therefore, utilization of AI in breast cancer screening and detection is of great significance, which can not only save time for radiologists, but also make up for experience and skill deficiency on some beginners. This article illustrates the basic technical knowledge regarding AI in breast ultrasound, including early machine learning algorithms and deep learning algorithms, and their application in the differential diagnosis of benign and malignant masses. At last, we talk about the future perspectives of AI in breast ultrasound.

Ultrasonographic imaging of inflammatory bowel disease in pediatric patients

Inflammatory bowel disease(IBD) is one of the most common chronic gastrointestinal diseases in pediatric patients.Choosing the optimal imaging modality for the assessment of gastrointestinal disease in pediatric patients can be challenging.The invasiveness and patient acceptance,the radiation exposure and the quality performance of the diagnostic test need to be considered.By reviewing the literature regarding imaging in inflammatory bowel disease the value of ultrasound in the clinical management of pediatric patients is highlighted.Transabdominal ultrasound is a useful,noninvasive method for the initial diagnosis of IBD in children;it also provides guidance for therapeutic decisions and helps to characterize and predict the course of the disease in individual patients.Ultrasound techniques including color Doppler imaging and contrast-enhanced ultrasound are promising imaging tools to determine disease activity and complications.Comparative studies between different imaging methods are needed.

How to perform gastrointestinal ultrasound: anatomy and normal findings

Gastrointestinal ultrasound is a practical, safe, cheap and reproducible diagnostic tool in inflammatorybowel disease gaining global prominence amongst clinicians. Understanding the embryological processes of the intestinal tract assists in the interpretation of abnormal sonographic findings. In general terms, the examination principally comprises interrogation of the colon, mesentery and small intestine using both lowfrequency and high-frequency probes. Interpretation of findings on GIUS includes assessment of bowel wall thickness, symmetry of this thickness, evidence of transmural changes, assessment of vascularity using Doppler imaging and assessment of other specific features including lymph nodes, mesentery and luminal motility. In addition to B-mode imaging, transperineal ultrasonography, elastography and contrast-enhanced ultrasonography are useful adjuncts. This supplement expands upon these features in more depth.

Nomogram for predicting transmural bowel infarction in patients with acute superior mesenteric venous thrombosis

BACKGROUND The prognosis of acute mesenteric ischemia(AMI)caused by superior mesenteric venous thrombosis(SMVT)remains undetermined and early detection of transmural bowel infarction(TBI)is crucial.The predisposition to develop TBI is of clinical concern,which can lead to fatal sepsis with hemodynamic instability and multi-organ failure.Early resection of necrotic bowel could improve the prognosis of AMI,however,accurate prediction of TBI remains a challenge for clinicians.When determining the eligibility for explorative laparotomy,the underlying risk factors for bowel infarction should be fully evaluated.AIM To develop and externally validate a nomogram for prediction of TBI in patients with acute SMVT.METHODS Consecutive data from 207 acute SMVT patients at the Wuhan Tongji Hospital and 89 patients at the Guangzhou Nanfang Hospital between July 2005 and December 2018 were included in this study.They were grouped as training and external validation cohort.The 207 cases(training cohort)from Tongji Hospital were divided into TBI and reversible intestinal ischemia groups based on the final therapeutic outcomes.Univariate and multivariate logistic regression analyses were conducted to identify independent risk factors for TBI using the training data,and a nomogram was subsequently developed.The performance of the nomogram was evaluated with respect to discrimination,calibration,and clinical usefulness in the training and external validation cohort.RESULTS Univariate and multivariate logistic regression analyses identified the following independent prognostic factors associated with TBI in the training cohort:The decreased bowel wall enhancement(OR=6.37,P<0.001),rebound tenderness(OR=7.14,P<0.001),serum lactate levels>2 mmol/L(OR=3.14,P=0.009)and previous history of deep venous thrombosis(OR=6.37,P<0.001).Incorporating these four factors,the nomogram achieved good calibration in the training set[area under the receiver operator characteristic curve(AUC)0.860;95%CI:0.771-0.925]and the external validation set(AUC 0.851;95%CI:0.796-0.897).The positive and negative predictive values(95%CIs)of the nomogram were calculated,resulting in positive predictive values of 54.55%(40.07%-68.29%)and 53.85%(43.66%-63.72%)and negative predictive values of 93.33%(82.14%-97.71%)and 92.24%(85.91%-95.86%)for the training and validation cohorts,respectively.Based on the nomogram,patients who had a Nomo-score of more than 90 were considered to have high risk for TBI.Decision curve analysis indicated that the nomogram was clinically useful.CONCLUSION The nomogram achieved an optimal prediction of TBI in patients with AMI.Using the model,the risk for an individual patient inclined to TBI can be assessed,thus providing a rational therapeutic choice.

Fortuitously discovered liver lesions

The fortuitously discovered liver lesion is a common problem. Consensus might be expected in terms of its work-up, and yet there is none. This stems in part from the fact that there is no preventive campaign involving the early detection of liver tumors other than for patients with known liver cirrhosis and oncological patients. The work-up (detection and differential diagnosis) of liver tumors comprises theoretical considerations, history, physical examination, laboratory tests, standard ultrasound, Doppler ultrasound techniques, contrastenhanced ultrasound (CEUS), computed tomography and magnetic resonance imaging, as well as imageguided biopsy. CEUS techniques have proved to be the most pertinent method; these techniques became part of the clinical routine about 10 years ago in Europe and Asia and are used for a variety of indications in daily clinical practice. CEUS is in many cases the first and also decisive technical intervention for detecting and characterizing liver tumors. This development is reflected in many CEUS guidelines, e.g. , in the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines 2004, 2008 and 2012 as well as the recently published World Federation for Ultrasound in Medicine and Biology-EFSUMB guidelines 2012. This article sets out considerations for making a structured work-up of incidental liver tumors feasible.

Artificial intelligence in liver ultrasound

Artificial intelligence(AI)is playing an increasingly important role in medicine,especially in the field of medical imaging.It can be used to diagnose diseases and predict certain statuses and possible events that may happen.Recently,more and more studies have confirmed the value of AI based on ultrasound in the evaluation of diffuse liver diseases and focal liver lesions.It can assess the severity of liver fibrosis and nonalcoholic fatty liver,differentially diagnose benign and malignant liver lesions,distinguish primary from secondary liver cancers,predict the curative effect of liver cancer treatment and recurrence after treatment,and predict microvascular invasion in hepatocellular carcinoma.The findings from these studies have great clinical application potential in the near future.The purpose of this review is to comprehensively introduce the current status and future perspectives of AI in liver ultrasound.

Liver elastography, comments on EFSUMB elastography guidelines 2013

Recently the European Federation of Societies for Ultrasound in Medicine and Biology Guidelines and Recommendations have been published assessing the clinical use of ultrasound elastography.The document is intended to form a reference and to guide clinical users in a practical way.They give practical advice for the use and interpretation.Liver disease forms the largest section,reflecting published experience to date including evidence from meta-analyses with shear wave and strain elastography.In this review comments and illustrations on the guidelines are given.

Artificial intelligence for hepatitis evaluation

Recently,increasing attention has been paid to the application of artificial intelligence(AI)to the diagnosis of diverse hepatic diseases,which comprises traditional machine learning and deep learning.Recent studies have shown the possible value of AI based data mining in predicting the incidence of hepatitis,classifying the different stages of hepatitis,diagnosing or screening for hepatitis,forecasting the progression of hepatitis,and predicting response to antiviral drugs in chronic hepatitis C patients.More importantly,AI based on radiology has been proven to be useful in predicting hepatitis and liver fibrosis as well as grading hepatocellular carcinoma(HCC)and differentiating it from benign liver tumors.It can predict the risk of vascular invasion of HCC,the risk of hepatic encephalopathy secondary to hepatitis B related cirrhosis,and the risk of liver failure after hepatectomy in HCC patients.In this review,we summarize the application of AI in hepatitis,and identify the challenges and future perspectives.

Comprehensive review of diagnostic modalities for early chronic pancreatitis

Chronic pancreatitis(CP)is a progressive condition caused by several factors and characterised by pancreatic fibrosis and dysfunction.However,CP is difficult to diagnose at an early stage.Various advanced methods including endoscopic ultrasound based elastography and confocal laser endomicroscopy have been used to diagnose early CP,although no unified diagnostic standards have been established.In the past,the diagnosis was mainly based on imaging,and no comprehensive evaluations were performed.This review describes and compares the advantages and limitations of the traditional and latest diagnostic modalities and suggests guidelines for the standardisation of the methods used to diagnose early CP.

Ultrasound imaging of abdominal sarcoidosis: State of the art

Since it has been recognized that sarcoidosis(SA) is not an exclusive disorder of the lungs but can also affect other organs such as the liver and spleen, efforts have been made to define specific imaging criteria for the diagnosis of the single organ involvement, and the concept has been reinforced that the exclusion of alternative causes is important to achieve the correct diagnosis. Ultrasound(US)is a useful tool to evaluate patients with suspected abdominal SA, such as of the liver, spleen, kidney, pancreas and other organs, showing findings such as organomegaly, focal lesions and lymphadenopathy. While the diagnosis of abdominal SA is more predictable in the case of involvement of other organs(e.g.,lungs), the problem is more complex in the case of isolated abdominal SA. The recent use of contrast-enhanced ultrasound and endoscopic ultrasound elastography has provided additional information about the enhancement patterns and tissue rigidity in abdominal SA. Here we critically review the role of US in abdominal SA, reporting typical findings and limitations of current evidence and by discussing future perspectives of study.

Interobserver agreement for contrast-enhanced ultrasound of liver imaging reporting and data system:A systematic review and metaanalysis

BACKGROUND Hepatocellular carcinoma is the most common primary liver malignancy.From the results of previous studies,Liver Imaging Reporting and Data System(LIRADS)on contrast-enhanced ultrasound(CEUS)has shown satisfactory diagnostic value.However,a unified conclusion on the interobserver stability of this innovative ultrasound imaging has not been determined.The present metaanalysis examined the interobserver agreement of CEUS LI-RADS to provide some reference for subsequent related research.AIM To evaluate the interobserver agreement of LI-RADS on CEUS and analyze the sources of heterogeneity between studies.METHODS Relevant papers on the subject of interobserver agreement on CEUS LI-RADS published before March 1,2020 in China and other countries were analyzed.The studies were filtered,and the diagnostic criteria were evaluated.The selected references were analyzed using the“meta”and“metafor”packages of R software version 3.6.2.RESULTS Eight studies were ultimately included in the present analysis.Meta-analysis results revealed that the summary Kappa value of included studies was 0.76[95%confidence interval,0.67-0.83],which shows substantial agreement.Higgins I2 statistics also confirmed the substantial heterogeneity(I2=91.30%,95%confidence interval,85.3%-94.9%,P<0.01).Meta-regression identified the variables,including the method of patient enrollment,method of consistency testing,and patient race,which explained the substantial study heterogeneity.CONCLUSION CEUS LI-RADS demonstrated overall substantial interobserver agreement,but heterogeneous results between studies were also obvious.Further clinical investigations should consider a modified recommendation about the experimental design.

Sonographic signs of neutropenic enterocolitis

AIM： To investigate the sonographic features at time of diagnosis and follow-up in patients with neutropenic enterocolitis. METHODS： The sonographic findings in 14 patients with neutropenic enterocolitis were described and evaluated regarding symptoms and clinical outcome. RESULTS： In all patients with neutropenic enterocolitis, the ileocoecal region was involved with wall thickening 〉10 mm. A transmural inflammatory pattern, hypervascularity of the thickened bowel wall and free abdominal fluid were the common findings. The sonographically revealed thickness of the bowel wall was associated with lethal outcome （P〈0.03）. In the 11 surviving patients, the improvement of clinical symptoms was accompanied by progressive reduction of intestinal wall thickness. CONCLUSION： High-end sonography of the bowel is a helpful tool for diagnosis, assessment of prognosis and follow-up of patients with neutropenic enterocolitis. The ultrasonographically revealed bowel thickness reflects the severity and the course of the disease, and seems to be predictive for the clinical outcome.