Contrast-enhanced endoscopic ultrasonography in digestive diseases

Current status of endoscopic ultrasound in the diagnosis of intraductal papillary mucinous neoplasms

The new Kyoto guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) provide evidence-based recommendations for the diagnosis and treatment of IPMN. Endoscopic ultrasonography (EUS) is a diagnostic modality with a high spatial resolution that allows detailed observation and obtaining cyst fluid or tissue samples via EUS-guided fine needle aspiration (EUS-FNA). Currently, EUS is an indispensable examination method for the diagnosis of pancreatic diseases. On the other hand, there have been concerns that EUS imaging tends to be highly operator-dependent, and may lack objectivity. Previous guidelines have assigned EUS as an option for patients with worrisome features. However, recent reports indicate that the sensitivity of EUS for the diagnosis of mural nodules (MNs) is more than 90%, comparable or superior to that of contrast-enhanced computed tomography or magnetic resonance cholangiopancreatography. The specific advantages of EUS in the diagnosis of IPMN are: (1) high spatial resolution imaging for the diagnosis of MNs, (2) contrast-enhanced EUS for differentiation of intra-cystic MNs from mucous clots, and (3) pathological diagnosis using EUS-FNA and differential diagnosis of a pancreatic cystic tumor by cystic fluid analysis. In order to utilize EUS in the diagnosis of IPMN, endoscopists are required to have the skills to provide sufficiently objective imaging findings.

Role of contrast-enhanced harmonic endoscopic ultrasonography (EUS) and EUS elastography in pancreatic lesions

Pancreatic cancers have a poor prognosis, and their incident rates have risen. Endoscopic ultrasonography (EUS) is an efficient and reliable diagnostic modality for pancreatic lesions, providing high spatial resolution. However, while EUS helps to detect minor pancreatic lesions, nearly all solid pancreatic lesions are hypoechoic, which creates difficulty in making differential diagnoses of pancreatic lesions. When diagnosing pancreatic lesions, the performance of image-enhanced EUS techniques is essential, such as EUS elastography or contrast-enhanced harmonic EUS (CH-EUS). CH-EUS diagnosis is based on assessing the vascularity of lesions, whereas tissue elasticity is measured via EUS elastography. Elastography is either strain or shear-wave, depending on the different mechanical properties being evaluated. The usefulness of enhanced EUS techniques is demonstrated in this review for the differential diagnosis of pancreatic lesions, including solid and cystic lesions, and pancreatic cancer staging.

The role of contrast-enhanced endoscopic ultrasound for biliary diseases

Contrast-enhanced endoscopic ultrasound (CE-EUS) has emerged as a promising diagnostic modality for assessing biliary diseases. CE-EUS is a noninvasive imaging technique that utilizes contrast agents to enhance the visualization of blood vessels and perfusion within target tissues. In the context of biliary diseases, CE-EUS allows for improved characterization of biliary lesions, aiding in differential diagnosis and treatment planning. This review highlights several key findings regarding the usefulness of CE-EUS in biliary disease assessment and therapeutic procedures.

Contrast-enhanced endoscopic ultrasound for swollen lymph nodes

Endoscopic ultrasound (EUS) is an important tool for the evaluation of lymphadenopathy, especially in intra-thoracic or intra-abdominal regions. EUS also provides tissue diagnosis via EUS fine-needle aspiration or biopsy. To select the target for biopsy or aspiration, conventional B-mode images are used for the evaluation, but this approach still lacks diagnostic accuracy. Contrast-enhanced EUS has been used to evaluate the vascularity of lesions. Most malignant lymphadenopathy shows heterogenous enhancement or defect of enhancement, while quantitative studies using time-intensity curves in contrast-enhanced harmonic EUS show a rapid decline in enhancement pattern. These findings are useful as an auxiliary method for tissue diagnosis or in cases in which tissue diagnosis is contraindicated.

Endoscopic sphincterotomy and endoscopic biliary stenting do not affect the sensitivity of transpapillary forceps biopsy for the diagnosis of bile duct adenocarcinoma

Background

The pathological evaluation of tissues with cholangitis is considered difficult, which can often occur after endoscopic sphincterotomy (EST) and endoscopic biliary stenting (EBS). This study aimed to evaluate the influence of a history of EST and EBS on the sensitivity of transpapillary forceps bile duct biopsy (TB) for bile duct adenocarcinoma.

Methods

This retrospective study included consecutive cases of bile duct adenocarcinoma in which TB was performed before July 2020 until the number exceeded that required to support statistical and noninferiority analyses of the sensitivity of TB between patients with and without each variable. The incidence of postprocedural adverse events related to each factor was also investigated.

Results

Overall, 280 samples were required in each group, and 437 subjects (792 samples) were included. The sensitivity of TB was 63.6% for the subjects and 59.6% for the biopsy samples. For the biopsy samples, the sensitivity did not differ significantly between samples from patients with and without a history of EST (59.1% vs. 58.9%, P = 0.952) and EBS (62.1% vs. 55.4%, P = 0.065). The sensitivity was significantly higher for samples from patients with jaundice (67.9% vs. 57.0%, P = 0.008). There were significantly fewer procedure-related adverse events in patients with a history of EST (10.8% vs. 19.0%, P = 0.017) and EBS (12.0% vs. 21.7%, P = 0.005).

Conclusions

A history of EST or EBS did not influence sensitivity of TB but significantly decreased the incidence of adverse events. To safely and reliably perform TB to diagnose bile duct adenocarcinoma, planning, including for EST and EBS, is necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02402-x.

Logistic Regression Analysis of Conventional Ultrasound, and Contrast-Enhanced Ultrasound Characteristics: Is It Helpful in Differentiating Benign and Malignant Superficial Lymph Nodes?

OBJECTIVES

This study aimed to screen the significant sonographic features for differentiation of benign and malignant superficial lymph nodes (LNs) by logistic regression analysis and fit a model to diagnose LNs.

METHODS

A total of 204 pathological LNs were analyzed retrospectively. All the LNs underwent conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) examinations. A total of 16 suspicious sonographic features were used to assess LNs. All variables that were statistically related to the diagnosis of LNs were included in the logistic regression analysis in order to ascertain the significant features of diagnosing LNs, and to establish a logistic regression analysis model.

RESULTS

The significant features in the logistic regression analysis model of diagnosing malignant LNs were absence of echogenic hilus, age, and absence of hilum after enhancement. According to the results of logistic regression analysis, the formula to predict whether LNs were malignant was established. The area under the receiver operating curve (ROC) was 0.908 and the accuracy, sensitivity, and specificity were 85.0%, 92.9%, and 85.3%, respectively.

CONCLUSION

The logistic regression model for the significant sonographic features of conventional US and CEUS is an effective and accurate diagnostic tool for differentiating malignant and benign LNs.

Application of neck ultrasound in the diagnosis of sarcoidosis

Objective

To explore the significance of neck ultrasound (NUS) combined with contrast-enhanced ultrasound (CEUS) in the diagnosis of sarcoidosis.

Methods

88 patients with evidence of intrathoracic lymphadenopathy and suspected sarcoidosis with enlarged cervical lymph nodes underwent NUS, CEUS, fine-needle aspiration and core needle biopsy when technically feasible were retrospectively analyzed in this study. Seven characteristics such as enhanced mode (EM), resolution time, color Doppler flow imaging (CDFI), fading time, peaking state-uniformity, strengthen the area and symmetry were considered to perform the logistic regression model.

Results

Of 88 patients included in this study, sarcoidosis was accounted in 20 cases, tuberculosis in 23 cases, malignancy in 22 cases and inflammatory lymph node in 23 cases. There were statistically significant differences in symmetry, lymphatic hilum, homogeneity, CDFI pattern and elasticity score between the sarcoidosis and non-sarcoidosis groups via NUS. Similarly, we also acknowledged a statistically significant differences in EM, homogeneity, presence or absence of necrosis between the sarcoidosis and non-sarcoidosis groups via CEUS to further group the non-sarcoidosis into tuberculosis, malignancy or inflammatory disorder. The percentage correction of prediction was 90% (18/20).

Conclusion

NUS combined with CEUS has characteristic features in sarcoidosis with cervical lymph node involvement, which is helpful for its diagnosis and differential diagnosis. The binary classification model of NUS combined with CEUS features can help differentiate sarcoidosis from non-sarcoidosis groups.

Feasibility of endoscopic ultrasonography using a 60-MHz ultrasound miniature probe in the upper gastrointestinal tract

PURPOSE

The use of higher frequencies in ultrasound allows for a more detailed image. This study aimed to investigate the feasibility of delineating the gastrointestinal wall using a 60-MHz miniature ultrasound probe.

METHODS

A phantom study was performed using a multipurpose ultrasonic phantom model, and the depth of imaging was evaluated using 60-MHz and 20-MHz miniature probes and 7.5-MHz conventional convex-type endoscopic ultrasonography. A total of 25 visualized areas from a total of 16 specimens from 16 patients were enrolled. The structures of the layers of the esophagus, stomach, and duodenum were evaluated using a 60-MHz probe and a pathological specimen created from endoscopically or surgically resected specimens.

RESULTS

The 60-MHz probe was able to render to a depth of 2 mm and visualize the esophagus, stomach, and duodenum in five layers, respectively, within the depiction range. The depiction ranges of the 20-MHz probe and 7.5-MHz conventional endoscopic ultrasonography were 5 mm and 60 mm, respectively. The 60-MHz probe visualized the muscularis mucosae as the fourth layer in the esophagus, the fourth layer in the stomach, and the second layer in the duodenum. Muscularis mucosae were delineated in almost all cases, except in two cases where the layered structure disappeared.

CONCLUSION

The 60-MHz probe provided good visualization of the muscularis mucosae and structure of the layers down to the submucosa, which improves the ability to diagnose the depth of early cancer invasion of the upper gastrointestinal tract, leading to more appropriate treatments.

Imaging diagnosis of autoimmune pancreatitis using endoscopic ultrasonography

The diagnosis of autoimmune pancreatitis (AIP) is challenging and should be achieved through the comprehensive evaluation of clinical, radiological, serological, and pathological evidence, as there is currently no single reliable diagnostic modality. Endoscopic ultrasonography (EUS) can reveal pancreatic parenchymal and ductal features in much more detail than any other existing imaging modality. In this article, we focused on three applications of EUS, i.e., conventional EUS imaging, EUS elastography (EUS-EG), and contrast-enhanced harmonic EUS (CEH-EUS), for the diagnosis of AIP. Diffuse hypoechoic areas, diffuse enlargement, bile duct wall thickening, and peripancreatic hypoechoic margins on conventional EUS are characteristic features of AIP, and the frequencies of these findings are significantly higher in AIP than in pancreatic cancer (PC). EUS-EG of the pancreatic parenchyma in AIP showed homogenous stiffness and that the elasticity of the pancreas may change after steroid therapy. CEH-EUS revealed focal or diffuse iso-enhancement in most AIP cases and hypo-enhancement in most PC cases. However, some AIP cases show a contrast enhancement pattern similar to that of PC. It should be noted that EUS findings of AIP may differ depending on its stage or disease activity. Differentiation from PC has become an increasingly important issue in the process of diagnosing AIP, and EUS, including elastography and contrast enhancement, could be a promising imaging modality for this purpose.

Role of EUS in detection of liver metastasis not seen by computed tomography or magnetic resonance imaging during staging of pancreatic, gastrointestinal, and thoracic malignancies

Background and Objectives:

Liver metastases might not be detected by computed tomography (CT) and magnetic resonance imaging (MRI) due to their small size, but they can be detected by EUS. Furthermore, EUS-FNA has a significant impact on improving the diagnostic accuracy of EUS. The purpose of this study was to assess the feasibility of EUS in detection of occult small hepatic focal lesions at the time of primary tumor staging, not seen by CT or MRI.

Methods:

This prospective study included 730 patients who underwent EUS for staging or sampling of gastrointestinal, pancreatic, or thoracic malignancy. The liver was examined thoroughly for detection of occult lesions. CT or MRI was done within 1 week of EUS examination.

Results:

EUS examination of the liver detected focal lesions in 150 patients (20.5%) and metastases in 118 patients (16.2%); meanwhile, CT and MRI detected focal lesions in 99 patients (13.6%) and metastases in 82 patients (11.2%). EUS missed focal lesions in 7 patients, 6 of which were liver metastases (1.0% and 0.8%, respectively), while CT and MRI missed focal lesions in 58 patients, 42 of which were metastases (7.9% and 5.8%, respectively), which were detected by EUS.

Conclusion:

Thorough dedicated EUS examination of the liver is a feasible useful tool for detection of small hepatic lesions missed by CT and MRI. It is not considered an extra financial burden to the patient or health-care system because those patients are indicated for EUS examination for evaluation of their original lesion in the first place. Furthermore, EUS-FNA can add another advantage in diagnosing the etiology of such lesions.

Recent Advances in Endosonography-Elastography: Literature Review

Ultrasonographic elastography is a modality used to visualize the elastic properties of tissues. Technological advances in ultrasound equipment have supported the evaluation of elastography (EG) in endosonography (EUS). Currently, the usefulness of not only EUS-strain elastography (EUS-SE) but also EUS-shear wave elastography (EUS-SWE) has been reported. We reviewed the literature on the usefulness of EUS-EG for various diseases such as chronic pancreatitis, pancreatic solid lesion, autoimmune pancreatitis, lymph node, and gastrointestinal and subepithelial lesions. The importance of this new diagnostic parameter, "tissue elasticity" in clinical practice might be applied not only to the diagnosis of liver fibrosis but also to the elucidation of the pathogeneses of various gastrointestinal diseases, including pancreatic diseases, and to the evaluation of therapeutic effects. The most important feature of EUS-EG is that it is a non-invasive modality. This is an advantage not found in EUS-guided fine needle aspiration (EUS-FNA), which has made remarkable progress in the field of diagnostics in recent years. Further development of artificial intelligence (AI) is expected to improve the diagnostic performance of EUS-EG. Future research on EUS-EG is anticipated.

Utility of multiphase contrast enhancement patterns on CEH-EUS for the differential diagnosis of IPMN-derived and conventional pancreatic cancer

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is reported as a high-risk factor for pancreatic cancer (PC) that includes IPMN-derived cancers (IPMC) and the development of invasive pancreatic ductal adenocarcinoma (PDAC) concomitant with IPMN. Since invasive IPMC and PDAC exhibit different oncological behaviors, their differentiation is clinically important. We aimed to investigate the use of contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) for the differential diagnosis between invasive IPMC and PDAC.

METHODS

This study involved 183 consecutive patients with PC (invasive IPMC: 42, PDAC concomitant with IPMN: 9, without IPMN: 132) who underwent CEH-EUS preoperatively. While investigating the patterns, enhanced effects in the solid part of the tumor were compared with those in the surrounding pancreatic parenchyma after administration of Sonazoid® and evaluated as hyperenhanced, isoenhanced, or hypoenhanced. We retrospectively compared the enhanced pattern of CEH-EUS by using multiphasic analysis and clinicopathological factors between invasive IPMC and PDAC.

RESULTS

In multiphase evaluations at 20, 40 and 60 s in CEH-EUS, 75.2% (106/141) of PDACs were hypoenhanced (-) at ≥2 of the 3 time points, with significant differences from those of invasive IPMC (P < 0.001). The solid tumor diameter was significantly larger in PDAC than in invasive IPMC, and the tumor stage and preoperative serum carbohydrate antigen 19-9 level were higher. After propensity score matching of stage and solid tumor diameter, contrast enhancement patterns were significantly more persistent in invasive IPMC than in PDAC (P = 0.0013).

CONCLUSIONS

Multiphase evaluation using CEH-EUS is a useful method for differentiating between invasive IPMC and PDAC.

EUS in Pediatrics: A Multicenter Experience and Review

Background/Aim: Endoscopic ultrasound (EUS) is a well-established tool used in the evaluation and treatment of a wide range of pathologies in adult medicine. EUS in pediatrics has been shown to be safe and technically effective, and its use continues to evolve. This article aims to describe the EUS experience at our tertiary-care centers with regard to safety, technical success, and its impact in clinical management. We also discuss the current and developing diagnostic and therapeutic uses for EUS in pediatrics such as in pancreaticobiliary disease, congenital anomalies, eosinophilic esophagitis, inflammatory bowel disease, and liver disease. Methods: This is a retrospective review of EUS performed by two pediatric gastroenterologists trained as endosonographers between April 2017 and November 2020. Patient demographics, procedure indication, procedure characteristics, technical success, and complications were collected. Literature review was performed to describe current and future uses of EUS in pediatrics. Results: Ninety-eight EUS were performed with 15 (15.3%) including fine needle aspiration/biopsy and 9 (9.2%) cases being therapeutic. Most common indications include choledocholithiasis (n = 31, 31.6%), pancreatic fluid collections (n = 18, 18.4%), chronic and acute recurrent pancreatitis (n = 14, 14.3%), and acute pancreatitis characterization (n = 13, 13.3%). Notable indications of pancreatic mass (n = 6, 6.1%) and luminal lesions/strictures (n = 6, 6.1%) were less common. Complications were limited with one instance of questionable GI bleeding after cystgastrostomy creation. Ninety-eight of 98 (100%) cases were technically successful. Conclusion/Discussion: EUS has been shown to be performed safely and successfully in the pediatric population by pediatric endosonographers. This study and review support its use in pediatric practice and demonstrate the wide variety of indications for EUS such as pancreatic cystgastrostomy, celiac plexus neurolysis, and evaluation of chronic pancreatitis. This literature review also demonstrates areas of potential development for EUS within the practice of pediatric gastroenterology.

Utility of quantitative contrast-enhanced ultrasound for the prediction of lymph node metastasis in patients with papillary thyroid carcinoma

OBJECTIVES

The aim of this study was to find the optimal parameters and cutoffs to differentiate metastatic lymph nodes (LNs) from benign LNs in the patients with papillary thyroid carcinoma (PTC) on the quantitative contrast-enhanced ultrasound (CEUS) features.

METHODS

A total of 134 LNs in 105 patients with PTCs were retrospectively enrolled. All LNs were evaluated by conventional ultrasound (US) and CEUS before biopsy or surgery. The diagnostic efficacy of CEUS parameters was analyzed.

RESULTS

Univariate analysis indicated that metastatic LNs more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, ring-enhancing margins, higher PI, larger AUC, longer TTP and DT/2 than benign LNs at pre-operative CEUS (p <  0.001, for all). Multivariate analysis showed that centripetal or asynchronous perfusion (OR = 3.163; 95% CI, 1.721-5.812), hyper-enhancement(OR = 0.371; 95% CI, 0.150-0.917), DT/2 (OR = 7.408; 95% confidence interval CI, 1.496-36.673), and AUC (OR = 8.340; 95% CI, 2.677-25.984) were predictive for the presence of metastatic LNs. The sensitivity and accuracy of the quantitative CEUS were higher than qualitative CEUS (75% vs 55 % and 83.6% vs 76.1 % , respectively).

CONCLUSIONS

Quantitative CEUS parameters can provide more information to distinguish metastatic from benign LNs in PTC patients; In particular, DT/2 and AUC have a higher sensitivity and accuracy in predicting the presence of metastatic LNs and reduce unnecessary sampling of benign LNs.

Meta-analysis of contrast-enhanced ultrasound and contrast-enhanced harmonic endoscopic ultrasound for the diagnosis of gallbladder malignancy

Background

The diagnosis between benign and malignant gallbladder lesions is sometimes difficult. The objective of this study is to assess whether contrast-enhanced ultrasound (CEUS) and contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) can be an accurate method for detecting gallbladder malignancy and to determine which imaging signs can be indicative of malignancy.

Methods

A study search of PubMed, Elsevier, and Sciencedirect was performed in May 2019. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve were used to examine the accuracy of CEUS and CH-EUS.

Results

Twenty-one studies were included in the meta-analysis. The pooled sensitivities of CEUS and CH-EUS were 0.81 (0.75–0.86) and 0.92 (0.86–0.95); the specificities were 0.94 (0.90–0.96) and 0.89 (0.69–0. 97); the DORs were 64 (32–127) and 89 (22–354); and the area under the SROC curves were 0.90 (0.87–0.92) and 0.92 (0.90–0.94). On CEUS, the diagnostic criterion for gallbladder malignancy according to four features were analyzed. Sensitivity and specificity were 0.75 (0.65–0.83) and 0.98 (0.85–1.00) for integrity of gallbladder wall; 0.69 (0.55–0.81) and 0.89 (0.77–0.95) for heterogeneous enhancement; 0.81 (0.71–0.88) and 0.88 (0.76–0.94) for irregular vessels; and 0.81 (0.66–0.91) and 0.75 (0.59–0.86) for washout time within 28 s. On CH-EUS, heterogeneous enhancement could be indicative of malignant lesions with a sensitivity of 0.94 (0.85–0.97); and the specificity was 0.92 (0.71–0.98).

Conclusions

CEUS and CH-EUS are promising and reliable imaging modalities with a high sensitivity and specificity for the diagnosis of gallbladder malignancy. CH-EUS might be more sensitive than CEUS with a higher sensitivity. In addition, irregular tralesional vessels and washout time within 28 s on CEUS and heterogeneous enhancement on CH-EUS are indicative of malignancy. However, larger scale and well-designed studies are warranted to verify our results.

The Roles of Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography in the Evaluation and Treatment of Chronic Pancreatitis in Children: A Position Paper From the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Pancreas Committee

INTRODUCTION

Pediatric chronic pancreatitis is increasingly diagnosed. Endoscopic methods [endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreatography (ERCP)] are useful tools to diagnose and manage chronic pancreatitis. Pediatric knowledge and use of these modalities is limited and warrants dissemination.

METHODS

Literature review of publications relating to use of ERCP and EUS for diagnosis and/or management of chronic pancreatitis with special attention to studies involving 0--18 years old subjects was conducted with summaries generated. Recommendations were developed and voted upon by authors.

RESULTS

Both EUS and ERCP can be used even in small children to assist in diagnosis of chronic pancreatitis in cases where cross-sectional imaging is not sufficient to diagnose or characterize the disease. Children under 15 kg for EUS and 10 kg for ERCP can be technically challenging. These procedures should be done optimally by appropriately trained endoscopists and adult gastroenterology providers with appropriate experience treating children. EUS and ERCP-related risks both include perforation, bleeding and pancreatitis. EUS is the preferred diagnostic modality over ERCP because of lower complication rates overall. Both modalities can be used for management of chronic pancreatitis -related fluid collections. ERCP has successfully been used to manage pancreatic duct stones.

CONCLUSION

EUS and ERCP can be safely used to diagnose chronic pancreatitis in pediatric patients and assist in management of chronic pancreatitis-related complications. Procedure-related risks are similar to those seen in adults, with EUS having a safer risk profile overall. The recent increase in pediatric-trained specialists will improve access of these modalities for children.

Feasibility and usefulness of endoscopic ultrasonography-guided shear-wave measurement for assessment of autoimmune pancreatitis activity: a prospective exploratory study

Purpose

To assess the feasibility and the clinical usefulness of a newly developed endoscopic ultrasonography (EUS) shear-wave elastography technique (EUS shear-wave measurement: EUS-SWM) in the diagnosis and treatment of autoimmune pancreatitis (AIP).

Methods

Tissue elasticity was measured in the pancreas in 160 patients. The success rate of EUS-SWMs, the velocity of the shear wave (Vs, m/s), and the reliability index of the Vs measurement (VsN) were evaluated, and the elasticity (median Vs) was compared between AIP patients (n = 14) and normal controls.

Results

A total of 3837 EUS-SWMs were performed without adverse events. Overall, 97.6% (3743/3837) were successful. The median VsN was 74%. The median Vs values of the pancreas were as follows: 2.22 m/s in the pancreatic head (push position), 2.36 m/s in the head (pull position), 1.99 m/s in the body, and 2.25 m/s in the tail. The median Vs of the AIP group (2.57 m/s) was significantly higher than that of the normal controls (1.89 m/s) (P = 0.0185). The mean Vs significantly decreased from 3.32 m/s to 2.46 m/s after steroid therapy (n = 6) (P = 0.0234).

Conclusion

EUS-SWM is feasible and generates credible results. EUS-SWM was a useful method for assessment of the effect of steroid therapy in AIP patients.

Electronic supplementary material

The online version of this article (10.1007/s10396-019-00944-4) contains supplementary material, which is available to authorized users.

Diagnostic yield of endoscopic ultrasound-guided biopsy of focal liver lesions

Endoscopic ultrasonography (EUS) has become an indispensable method for diagnosis and therapeutic procedures in gastroenterology. As experience with this technique grows, new indications continue to emerge. Due to the vicinity of the transducer to the liver, endoscopic ultrasonography provides detailed images of the liver segments and its vascular and biliary structures. Endosonographers have made an effort to define a clinical role for endoscopic ultrasound in liver diseases; however, not much is known about endoscopic ultrasound guided fine needle aspiration (EUS-FNA) in hepatic focal lesions. This review summarizes the available evidence regarding the usefulness of endoscopic ultrasound-guided fine needle aspiration in patients with focal liver lesions.

Contrast-enhanced ultrasound for the differential diagnosis between benign and metastatic superficial lymph nodes: a meta-analysis

Purpose

Contrast-enhanced ultrasound (CEUS) is a new technique used to distinguish benign from metastatic superficial lymph nodes (LNs) with variable accuracy. The objective of this meta-analysis was to evaluate the accuracy of CEUS for the diagnosis of superficial metastatic LNs.

Methods

A comprehensive literature search of PubMed, Web of Science, Medline, Embase, and the Cochrane Library was performed until April 2018. Nine articles reporting the diagnosis of 436 LNs by CEUS were investigated. The Mantel–Haenszel and DerSimonian–Laird methods were used to analyze pooled sensitivity, specificity, diagnostic OR, positive likelihood ratio (LR), and negative LR, and a summary receiver operating characteristic (SROC) curve was also evaluated.

Results

The pooled sensitivity and specificity of CEUS for the differential diagnosis of benign and metastatic superficial LNs were 0.88 (95% CI, 0.83–0.92) and 0.80 (95% CI, 0.74–0.85), respectively. The pooled positive LR, negative LR, and diagnostic OR were 4.36 (95% CI, 2.38–7.99), 0.17 (95% CI, 0.10–0.31), and 32.75 (95% CI, 11.08–96.84), respectively. SROC area under the curve (AUC) was 0.9288. The subgroup analysis excluding outliers implied that the heterogeneity was almost eliminated, and the pooled sensitivity and specificity were 0.87 (95% CI, 0.81–0.92) and 0.79 (95% CI, 0.71–0.85), respectively. The SROC AUC was 0.8950.

Conclusion

CEUS, a novel imaging modality for the characterization of superficial LNs, shows a high sensitivity and specificity in the diagnosis of superficial metastatic LNs. The different diagnostic standards, contrast agents, and contrast modes contribute to a considerable level of heterogeneity among studies. A uniform standard for distinguishing between benign and metastatic LNs is needed for further clinical application.

Potential role of contrast-enhanced ultrasound for the differentiation of malignant and benign gallbladder lesions in East Asia: A meta-analysis and systematic review

BACKGROUND

The purpose of this study was to systematically review and evaluate the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in differentiating malignant and benign gallbladder lesions.

METHODS

We conducted a comprehensive search on PubMed, Embase, and Cochrane Library for all potential relevant articles published before December 2017. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) and area under the curve (AUC) of summary receiver operating characteristic (SROC) were calculated by Meta-Disc Version 1.4 and STATA 12.0.

RESULTS

Twelve eligible studies were included in our study. A total of 1044 patients were assessed. The pooled sensitivity and specificity were 0.81 (95% confidence interval [CI], 0.77-0.84; inconsistency index [I] = 84.5%) and 0.87 (95% CI, 0.85-0.89; I = 94.4%), respectively. The pooled DOR was 58.84 (95% CI, 32.39-106.88; I = 51.9%). The AUC was 0.9371. According to Deek funnel plot asymmetry test, there was no significant publication bias (P = .31).

CONCLUSIONS

The results yielded from the available evidence suggest that CEUS is a promising and adjuvant imaging technique to conventional ultrasound for the differential diagnosis of benign and malignant gallbladder lesions.

Transabdominal ultrasound elastography of the esophagogastric junction predicts reflux esophagitis

PURPOSE

Abdominal ultrasound (US) can visualize the esophagogastric junction (EGJ) as a hyperechoic area in the dorsal portion of the lateral segment of the liver. We prospectively evaluated the EGJ using US elastography (US-EG) in patients with reflux esophagitis (RE) to examine prediction of distal esophageal function.

METHODS

Of 108 patients undergoing US-EG and esophagogastroduodenoscopy, 102 in whom the EGJ was observed for ≥ 15 s were included. The subjects were divided into a RE group (n = 41, Grade M/A/B:24/13/4 according to modified Los Angeles Classification) and a non-RE group (n = 61). Direct strain elastography (LOGIQ E9, GE Healthcare), which gives a semi-quantitative elasticity index within a region of interest including the lateral segment, was used as a standard for measurement of the change in stiffness (CS) at the EGJ.

RESULTS

The number of CS as determined by US-EG was 6.0 (5.5-6.7) in the RE group and 8.6 (6.6-10.0) in the non-RE group (P < 0.0001). In ROC analysis, the AUC was 0.8415 for diagnosis of RE using the number of CS. At a cut-off of 7.7, the sensitivity, specificity, and accuracy for diagnosis were 92.7, 65.6, and 74.5%, respectively.

CONCLUSION

The presence of RE can be predicted based on US-EG.

Multiphase evaluation of contrast-enhanced endoscopic ultrasonography in the diagnosis of pancreatic solid lesions

BACKGROUND/OBJECTIVES

Time-intensity curve (TIC) under contrast-enhanced EUS (CE-EUS) allows continuous and quantitative evaluation of targeted area in the pancreas. However, TIC is not always available and the procedure is complicated. We aimed to propose a simplified method by evaluating multiple phases of CE-EUS in the diagnosis of pancreatic solid lesions.

METHODS

We retrospectively reviewed 210 patients with pancreatic solid lesions including 142 with pancreatic ductal cancer (PDAC), 31 with pancreatic neuroendocrine neoplasm, 13 with solid pseudopapillary neoplasm and 24 with mass-forming pancreatitis who underwent CE-EUS and achieved final diagnoses. The CE-EUS images were continuously recorded for 60 s, and each image at 20, 40 and 60 s was used for the evaluation. The images were classified into three patterns as hypoechoic, hyperechoic and isoechoic vascular patterns compared with the surrounding pancreas, and the relevance between the multiphase evaluation of CE-EUS and each disease group was investigated.

RESULTS

In PDAC group, majority of the lesions showed hypovascular pattern at 20 or 40 s after injection of contrast medium following early enhancement. The sensitivity, specificity and accuracy of PDAC pattern in the differentiation of PDAC from other lesions was 83.1%, 86.8% and 84.3%, respectively. On histopathological analysis, significant differences were seen in histologic types, infiltration (INF), and neural invasion (ne) between those who showed PDAC pattern and those who didn't.

CONCLUSIONS

Multiphase evaluation of CE-EUS is convenient and useful method for the differentiation of pancreatic solid lesions which can be alternatively used for TIC.

Endoscopic ultrasound in diagnosis of solid pancreatic lesions: Elastography or contrast-enhanced harmonic alone versus the combination

BACKGROUND AND STUDY AIMS

Endoscopic ultrasound (EUS) elastography (EUS-E) and contrast-enhanced harmonic EUS (CH-EUS) are useful methods for the diagnosis of pancreatic lesions. This study aims to compare the accuracy of combined EUS-E and CH-EUS with that of EUS-E or CH-EUS alone in the differential diagnosis of pancreatic solid lesions.

PATIENTS AND METHODS

 One hundred thirty-six patients with solid pancreatic lesions underwent EUS with both EUS-E and CH-EUS were included. Diagnoses were classified as adenocarcinoma, neuroendocrine tumor (NET), and inflammatory pseudotumor in 95, 22, and 19 patients, respectively. EUS records in each case were rearranged into 3 groups: EUS-E, CH-EUS, and combination. Each modality was randomly reviewed by 3 reviewers with different levels of clinical experience. Sensitivity, specificity, and accuracy of each modality according to each diagnosis group were evaluated. For the combined diagnosis populations, the proportions of correct diagnoses among the 3 modalities were compared by using the multivariate logistic regression analysis.

RESULTS

The accuracies of EUS-E, CH-EUS, and the combination of them were 68.4 %, 65.4 %, and 75.7 %, respectively, for adenocarcinoma group; 83.8 %, 82.4 %, and 86.8 % for NET group; 80.1 %, 78.7 %, and 81.6 % for inflammatory pseudotumor group. The multivariate logistic regression analysis for the combined diagnosis populations showed that the proportion of correct diagnoses when EUS-E and CH-EUS were combined was slightly higher than with the other 2 modalities, although the significant differences among them were not observed.

CONCLUSION

EUS-E and CH-EUS combined may improve differential diagnosis of solid pancreatic lesions compared with use of the individual modalities.

New Imaging Techniques for Endoscopic Ultrasonography: Contrast-Enhanced Endoscopic Ultrasonography

Conventional endoscopic ultrasonography (EUS) has limitations in the diagnosis of solid masses. Because most are depicted as a hypoechoic mass, without cytology or biopsy, it can be difficult to distinguish inflammatory masses from malignancy. Recently developed, contrast-enhanced harmonic EUS (CH-EUS) has improved characterization of digestive lesions by depicting microvessels and parenchymal perfusion, particularly for differentiating pancreatic cancer from other pancreatic solid lesions, identifying mural nodules in intraductal papillary mucinous neoplasms, and estimating malignant potential of gastrointestinal stromal tumors. CH-EUS is complementary to EUS-guided fine-needle aspiration for diagnosing pancreatic lesions, staging, and predicting chemotherapy response.

Clinical Value of Contrast-Enhanced Harmonic Endoscopic Ultrasonography in the Differential Diagnosis of Pancreatic and Gallbladder Masses

Background/Aims

Recent studies have revealed that contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) is beneficial in the differential diagnosis of malignant neoplasms of the pancreas and gallbladder from benign masses, in terms of the evaluation of microvasculature and real-time perfusion. In this study, we aimed to prove the clinical value of CEH-EUS in the differential diagnosis of pancreatic and gallbladder masses by direct comparison with that of conventional EUS.

Methods

We reviewed the sonographic images and medical information of 471 patients who underwent conventional EUS and CEH-EUS for the diagnosis of pancreatic and gallbladder masses at a single medical center (Severance Hospital, Seoul, Korea) between March 2010 and March 2016.

Results

The enhancement pattern of CEH-EUS of the pancreatic solid masses showed higher sensitivity and specificity in differentiating pancreatic adenocarcinoma and neuroendocrine tumors (82.0% and 87.9% for pancreatic adenocarcinoma and 81.1% and 90.9% for neuroendocrine tumors, respectively), and the area under the receiver operating characteristic curves was higher than that of conventional EUS. The enhancement texture of CEH-EUS of the gallbladder masses showed a higher sensitivity in differentiating malignant masses than that of conventional EUS; however, the difference between the areas under the receiver operating characteristic curves was not statistically significant.

Conclusions

CEH-EUS can complement conventional EUS in the diagnosis of pancreatic and gallbladder masses, in terms of the limitations of the latter.

Contrast-enhanced endoscopic ultrasound for differential diagnosis of pancreatic cancer: an updated meta-analysis

Aim

We aim to assess the diagnostic value of contrast-enhanced endoscopic ultrasound (CE-EUS) for pancreatic cancer and inflammatory lesions by pooling current evidence.

Materials and Methods

A systematical search of PubMed, Web of Science and the Cochrane Library was performed from inception to January 2016. Two authors independently screened and extracted detailed data from included studies. A random effect model was adopted to estimate the pooled sensitivity, specificity in order to determine the diagnostic ablitity of CE-EUS. Furthermore, we conducted the meta-regression and subgroup analyses to explore possible heterogeneity.

Results

Eighteen eligible studies enrolling 1668 patients were finally included in the study. The pooled sensitivity of CE-EUS for distinguishing pancreatic cancers from solid inflammatory masses was 0.93 (95% CI, 0.91–0.94), and the specificity was 0.88 (95% CI, 0.84–0.90). The area under summary receiver operating characteristic curve yielded 0.97. No publication bias was observed by Deeks’ funnel plot in current meta-analysis.

Conclusions

We provided evidence that CE-EUS is a promising modality for differential diagnosis of pancreatic adenocarcinomas. Further multicenter prospective studies should be carried out to certify its utility.

Gastric plexiform fibromyxoma resected by endoscopic submucosal dissection after observation of chronological changes: A case report

A 66-year-old man was diagnosed with a gastric submucosal tumor. Endoscopic ultrasound (EUS) revealed an iso/hypoechoic mass in the third layer. No malignant cells were detected in a histological examination. Yearly follow-up endoscopy and EUS showed the slow growth of the tumor. Endoscopic submucosal dissection (ESD) was performed and a glistening tumor was resected. The lesion showed a multinodular plexiform growth pattern consisting of spindle cells with an abundant fibromyxoid stroma that was rich in small vessels. The tumor was diagnosed as plexiform fibromyxoma (PF) by immunohistochemistry. Although difficulties are associated with reaching a diagnosis preoperatively, chronological changes on EUS may contribute to the diagnosis of PF. ESD may also be useful in the diagnosis and treatment of PF.

Smart Microbubble Eluting Theranostic Stent for Noninvasive Ultrasound Imaging and Prevention of Restenosis

A pH-responsive microbubble-eluting theranostic stent is developed for real-time ultrasound imaging of stent implanted blood vessels and dissolution of fat-rich plaques to prevent the blocking of blood vessels in rats. This smart theranostic stent can be effectively applied to facilitate noninvasive monitoring and prevent restenosis after stent implantation.

Early detection of pancreatic cancer: impact of high-resolution imaging methods and biomarkers

High-resolution imaging methods (HRIMs) and biomarkers present the second step of pancreatic cancer (PC) diagnostics in at-risk individuals. These include patients with positive risk factors, early symptoms, nonresponders to the initial antidiabetic therapy, patients older than 50 years of age with new-onset unstable diabetes requiring insulin as well as patients with long-term insulin-non-dependent diabetes and recent (up to 6 months) failure of antidiabetic therapy. The procedures should be started without delay and the co-operation between the primary and tertiary medical centers is highly desirable. An early indication of HRIMs and biomarkers is a prerequisite for the diagnosis of a resectable PC. This publication reviews the recent contribution of HRIMs and biomarkers toward an early diagnosis of PC.

The Expanding Role of Contrast-Enhanced Endoscopic Ultrasound in Pancreatobiliary Disease

Since its introduction into clinical practice in the 1980s, endoscopic ultrasound (EUS) has been described as a good imaging modality for the diagnosis of pancreatobiliary diseases. However, differential diagnosis of certain lesions based only on B-mode ultrasound images can be challenging. Clinical use of ultrasound contrast agents has expanded the utility of EUS from that of detection to characterization of pancreatobiliary lesions based on the enhancement features of contrast-enhanced EUS (CE-EUS). Current low mechanical index techniques for CE-EUS using second-generation contrast agents have a number of distinct advantages over conventional diagnostic modalities in evaluating pancreatobiliary lesions, including real-time assessment of perfusion pattern, availability, and the absence of exposure to radiation. This article describes the technical aspects of CE-EUS and reviews the expanding indications in pancreatobiliary diseases and further development of this technique.

New endoscopic ultrasound techniques for digestive tract diseases: A comprehensive review

Endoscopic ultrasound (EUS) is one of the most important modalities for the diagnosis of digestive tract diseases. EUS has been evolving ever since it was introduced. New techniques such as elastography and contrast enhancement have emerged, increasing the accuracy, sensitivity and specificity of EUS for the diagnosis of digestive tract diseases including pancreatic masses and lymphadenopathy. EUS-elastography evaluates tissue elasticity and therefore, can be used to differentiate various lesions. Contrast-enhanced EUS can distinguish benign from malignant pancreatic lesions and lymphadenopathy using the intravenous injection of contrast agents. This review discusses the principles and types of these new techniques, as well as their clinical applications and limitations.

Comparison of the clinical value of multi-band mucosectomy versus endoscopic mucosal resection for the treatment of patients with early-stage esophageal cancer

The present study aimed to compare the clinical value of multi-band mucosectomy (MBM) versus endoscopic mucosal resection (EMR) for the treatment of patients with early-stage esophageal cancer. Between January 2011 and December 2012, 68 patients with early-stage esophageal cancer who underwent MBM and EMR were enrolled into the present study. The curative resection rate, duration of surgery, complications and follow-up records were retrospectively analyzed. Of the 68 patients included, 33 were treated with MBM and 35 with EMR. There was no significant difference in the rate of complete resection between the MBM and EMR groups (P>0.05). The mean duration of surgery in the MBM group was statistically lower than that in the EMR group (P<0.05). There was no statistically significant difference in the intraoperative and post-operative complications between the MBM and EMR groups (P>0.05). Esophageal cancer reoccurred in 2 patients treated with MBM and 1 patient treated with EMR during the follow-up period (range, 3-24 months). Overall, MBM can be considered a better surgical option for the management of patients with early-stage esophageal cancer, as it offers higher histological curative resection rates and improved safety. However, further studies and a larger follow-up period are required to confirm the long-term curative effect.

Clinical evaluation of new diagnostic modalities of endoscopic ultrasound for pancreaticobiliary diseases

Endoscopic ultrasonography (EUS) is currently an integral tool for work-up of pancreaticobiliary neoplasms. Tissue acquisition by EUS is possible with fine-needle aspiration (FNA) cytology and histology. However, FNA still carries some limitations and risks of complications. The use of image-enhanced EUS may improve detection and characterization of pancreaticobiliary neoplasms and complement FNA. The present article aims to provide an overview of the current development of contrast-enhanced imaging and elastography in EUS and their potential application in the diagnosis of pancreaticobiliary diseases.

Current status of tissue harmonic imaging in endoscopic ultrasonography (EUS) and EUS-elastography in pancreatobiliary diseases

Endoscopic ultrasonography (EUS) has high spatial and contrast resolution, and is thought to be one of the most reliable and efficient diagnostic modalities for pancreatobiliary diseases. Recent progress in EUS, especially in the development of the electronic scanning method, has enabled the application of several utilities and software of a high-end transabdominal ultrasound apparatus as an image-enhanced EUS. Tissue harmonic imaging (THI) is a novel US acquisition method that provides better US images by using second harmonic signals. The potential advantages of THI are improved lateral resolution, reduced side lobe artifact and an increased signal-to-noise ratio. EUS-elastography is another novel technique that provides information about the distributed pattern of tissue hardness. Clinical benefits of EUS-elastography for the differential diagnosis of pancreatic tumors and the evaluation of pancreatic fibrosis have been reported. It is necessary to develop a unified and objective method of imaging and analysis to increase the use of EUS-elastography in the future.

Gastric foregut cystic developmental malformation: Case series and literature review

Foregut cystic developmental malformation (FCDM) is a very rare lesion of the alimentary tract, especially in the stomach. We discuss the concepts of gastric duplication cyst, bronchogenic cysts, and FCDM. Nomenclature has been inconsistent and confusing, but, by some definitions, gastric duplication cysts involve gastric mucosa and submucosal glands, bronchogenic cysts involve respiratory mucosa with underlying cartilage and glands, and FCDM lacks gastric mucosa or underlying glands or cartilage but has pseudostratified ciliated columnar epithelium (PCCE). We searched our departmental case files from the past 15 years and identified 12 cases of FCDM in the alimentary tract. We summarize the features of these 12 cases including a report in detail on a 52-year-old man with a submucosal cyst lined with simple PCCE and irregular and stratified circular muscle layers that merged with gastric smooth muscle bundles near the lesser curvature of the gastric cardia. A literature review of cases with this histology yielded 25 cases. We propose the term gastric-FCDM for such cases. Our own series of 12 cases confirms that preoperative recognition of the entity is infrequent and problematic. The rarity of this developmental disorder, as well as a lack of understanding of its embryologic origins, may contribute to missing the diagnosis. Not appreciating the diagnosis preoperatively can lead to an inappropriate surgical approach. In contrast, presurgical recognition of the entity will contribute to a good outcome and reduced risk of complications.

Usefulness of endoscopic ultrasound-guided fine needle aspiration in the diagnosis of hepatic, gallbladder and biliary tract Lesions

Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) of the liver is a safe procedure in the diagnosis and staging of hepatobiliary malignancies with a minimal major complication rate. EUS-FNA is useful for liver lesions poorly accessible to other imaging modalities of the liver. EUS-guided FNA of biliary neoplasia and malignant biliary stricture is superior to the conventional endoscopic brushing and biopsy.

Sudden disappearance of the blood flow in a case of pancreatic acinar cell carcinoma

A 55-year-old man was referred to our hospital for a further examination of a pancreatic cystic tumor with a solid component exhibiting vascularity. A few days later, the patient was admitted with a complaint of sudden severe epigastric pain. Enhanced CT showed the loss of vascularity in the tumor. In particular, contrast-enhanced endoscopic ultrasonography (EUS) clearly demonstrated the disappearance of the blood flow, and a histological examination revealed acinar cell carcinoma with central necrosis. To our knowledge, this is the first case in the literature of acinar cell carcinoma associated with the sudden disappearance of vascularity. In this case, contrast-enhanced harmonic EUS was especially useful for assessing the degree of vascularity.

New approaches to gastric cancer staging: Beyond endoscopic ultrasound, computed tomography and positron emission tomography

Currently, there is no single gold standard modality for staging of gastric cancer and several methods have been used complementarily in the each clinical situation. To make up for the shortcomings of conventional modalities such as endoscopic ultrasound, computed tomography and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography, numerous attempts with new approaches have been made for gastric cancer staging. For T staging, magnifying endoscopy with narrow-band was evaluated to differentiate mucosal cancer from submucosal cancer. Single/double contrast-enhanced ultrasound and diffusion-weighted magnetic resonance imaging were also tried to improve diagnostic accuracy of gastric cancer. For intraoperative staging with sentinel node mapping, indocyanine green infrared and fluorescence imaging was introduced. In addition, to detect micrometastasis, real-time reverse transcription-polymerase chain reaction system with multiple markers was studied. Staging laparoscopy using 5-aminolevulinic acid-mediated photodynamic diagnosis and percutaneous diagnostic peritoneal lavage were also evaluated. However, most studies reporting new staging methods is preliminary and further studies for validation in clinical practice are needed. In this mini-review, we discuss new progress in gastric cancer staging. Especially, we focus on new diagnostic approach to gastric cancer staging beyond the conventional modalities and briefly review the remarkable clinical results of the studies published over the past three years.

Radiofrequency ablation of pancreatic neuroendocrine tumors: a pilot study of feasibility, efficacy, and safety

OBJECTIVE

This study aimed to assess the feasibility, safety, and efficacy of radiofrequency ablation (RFA) of pancreatic neuroendocrine tumors (PNETs).

METHODS

We performed RFA on 10 patients (7 women) aged 38 to 75 years with histologically diagnosed PNETs (secreting in 3 cases) who could not or would not undergo surgical resection. Tumor nodules (diameter, 0.9-2.9 cm; mean [SD], 1.6 [0.5] cm) were located in the head (n = 7) or body (n = 3) of the pancreas. Ultrasound-guided RFA was performed percutaneously (n = 7), endoscopically (n = 1), or intraoperatively (n = 2) using commercially available equipment. Complete ablation was defined as absence of enhancing tissue at the tumor site on contrast-enhanced imaging studies and normalization of previously elevated serum hormone levels.

RESULTS

Complete ablation was achieved with 1 (n = 9) or 2 (n = 1) RFA procedures. All neuroendocrine syndromes regressed within 24 hours of treatment. No recurrences were observed during follow-up (range, 12-60 months; median [SD], 34 [14] months). No deaths occurred. Major complications included acute pancreatitis in 3 patients, 2 of whom developed pancreatic fluid collections that were successfully managed with ultrasound-guided drainage and endoscopy.

CONCLUSIONS

Radiofrequency ablation is a feasible, safe, and effective option for patients with small PNETs who cannot or do not want to undergo surgical resection.

Quantitative analysis of diagnosing pancreatic fibrosis using EUS-elastography (comparison with surgical specimens)

BACKGROUND

An accurate diagnosis of pancreatic fibrosis is clinically important and may have potential for staging chronic pancreatitis. The aim of this study was to diagnose the grade of pancreatic fibrosis through a quantitative analysis of endoscopic ultrasound elastography (EUS-EG).

METHODS

From September 2004 to October 2010, 58 consecutive patients examined by EUS-EG for both pancreatic tumors and their upstream pancreas before pancreatectomy were enrolled. Preoperative EUS-EG images in the upstream pancreas were statistically quantified, and the results were retrospectively compared with postoperative histological fibrosis in the same area. For the quantification of EUS-EG images, 4 parameters (mean, standard deviation, skewness, and kurtosis) were calculated using novel software. Histological fibrosis was graded into 4 categories (normal, mild fibrosis, marked fibrosis, and severe fibrosis) according to a previously reported scoring system.

RESULTS

The fibrosis grade in the upstream pancreas was normal in 24 patients, mild fibrosis in 19, marked fibrosis in 6, and severe fibrosis in 9. Fibrosis grade was significantly correlated with all 4 quantification parameters (mean r = -0.75, standard deviation r = -0.54, skewness r = 0.69, kurtosis r = 0.67). According to the receiver operating characteristic analysis, the mean was the most useful parameter for diagnosing pancreatic fibrosis. Using the mean, the area under the ROC curves for the diagnosis of mild or higher-grade fibrosis, marked or higher-grade fibrosis and severe fibrosis were 0.90, 0.90, and 0.90, respectively.

CONCLUSIONS

An accurate diagnosis of pancreatic fibrosis may be possible by analyzing EUS-EG images.

Contrast-enhanced endoscopic ultrasonography: advance and current status

Endoscopic ultrasonography (EUS) technology has undergone a great deal of progress along with the color and power Doppler imaging, three-dimensional imaging, electronic scanning, tissue harmonic imaging, and elastography, and one of the most important developments is the ability to acquire contrast-enhanced images. The blood flow in small vessels and the parenchymal microvasculature of the target lesion can be observed non-invasively by contrast-enhanced EUS (CE-EUS). Through a hemodynamic analysis, CE-EUS permits the diagnosis of various gastrointestinal diseases and differential diagnoses between benign and malignant tumors. Recently, mechanical innovations and the development of contrast agents have increased the use of CE-EUS in the diagnostic field, as well as for the assessment of the efficacy of therapeutic agents. The advances in and the current status of CE-EUS are discussed in this review.

Contrast-enhanced endoscopic ultrasound

Compared to other imaging modalities, endoscopic ultrasound (EUS) has limitations in terms of image enhancement. However, with the availability of contrast agents in ultrasonography, EUS has evolved. Contrast-enhanced Doppler EUS (CD-EUS) enhances Doppler signals from vessels and is useful for characterizing lesions detected by EUS. Moreover, contrast-enhanced harmonic EUS (CH-EUS) with second-generation ultrasound contrast agents and a broad band transducer allows microvessels and parenchymal perfusion to be visualized. Vascularity can also be quantitatively analyzed during CH-EUS by generating a time-intensity curve. CE-EUS is useful for characterizing pancreatic lesions and can detect pancreatic adenocarcinomas with a sensitivity of 94%and a specificity of 89% as a result of the hypo-enhancement of these lesions. Indeed, CH-EUS is superior to multiple detector-computed tomography in terms of the differential diagnosis of small lesions that are ≤2 cm. CH-EUS complements EUS-guided fine-needle aspiration (EUS-FNA) as it identifies the EUS-FNA target and lesions with false-negative EUS-FNA findings. CH-EUS is also used to estimate the malignant potential of gastrointestinal stromal tumors and helps to differentiate between malignant and benign lymphadenopathy.

Utility of contrast-enhanced harmonic EUS in the diagnosis of malignant gallbladder polyps (with videos)

BACKGROUND

The differential diagnosis between benign and malignant polyps of the gallbladder (GB) is often challenging.

OBJECTIVES

To evaluate whether contrast-enhanced harmonic EUS (CEH-EUS) might be an accurate method for discriminating malignant GB polyps from benign polyps.

DESIGN

Observational study.

SETTING

Tertiary care medical center.

PATIENTS

Ninety-three patients with GB polyps larger than 10 mm in diameter that were detected by conventional EUS underwent CEH-EUS for evaluation of microvasculature.

INTERVENTION

CEH-EUS was performed using a radial echoendoscope and the extended pure harmonic detection mode.

MAIN OUTCOME MEASUREMENTS

The abilities of conventional EUS and CEH-EUS to diagnose malignant polyp were compared. Two blinded reviewers classified the perfusion images into 3 categories: diffuse enhancement, perfusion defect, or nonenhancement. The vessel images were categorized as having a regular spotty vessel, an irregular vessel, or no vessels.

RESULTS

An irregular vessel pattern determined by CEH-EUS aided in the diagnosis of malignant polyps with a sensitivity and specificity of 90.3% and 96.6%, respectively. The presence of perfusion defects, determined by CEH-EUS, was calculated to diagnose malignant polyps with a sensitivity and specificity of 90.3% and 94.9%, respectively. Based on the definitely determined diagnosis, sensitivity and specificity for CEH-EUS were 93.5% and 93.2% versus 90.0% and 91.1% for conventional EUS. In 8 cases, management changed after CEH-EUS.

LIMITATIONS

A tertiary medical center with a limited number of patients.

CONCLUSIONS

The presence of irregular intratumoral vessels or perfusion defects seen on CEH-EUS may be sensitive and accurate predictors of malignant GB polyps. CEH-EUS offers slightly improved diagnostic accuracy compared with EUS.

Should plastic stents be avoided in all unresectable malignant perihilar biliary strictures?

Clinical guidelines of the European Society of Gastrointestinal Endoscopy recommend the insertion of self-expandable metallic stents (SEMS) as opposed to plastic stents (PS) in patients with unresectable malignant perihilar stricture (MHS). However, PS are cheaper and easier to insert into the biliary duct compared to SEMS. Furthermore, PS are removable and easy to move into subsequent drainage procedures. We conducted the present retrospective single-center study to elucidate the predictive factors associated with stent patency period duration in patients with unresectable MHS who would benefit from a long patency period after PS placement. This study included 56 consecutive patients with unresectable MHS who were drained using PS. PS failure occurred in 26 (46.4%) patients. The median patency period was 72 days (95% confidence interval: 29.8-114). The only significant predictive factor associated with the length of the stent patency period was history of previous endoscopic sphincterotomy (EST). Median patency periods with and without previous EST were 28 and 109 days, respectively (P = 0.016). In conclusion, we suggest that conventional biliary drainage with PS is still a suitable option for the treatment of unresectable MHS in patients without previous EST.

Foregut duplication of the stomach diagnosed by endoscopic ultrasound guided fine-needle aspiration cytology: case report and literature review

Gastric duplication cyst (GDC) with a pseudostratified columnar ciliated epithelium is an uncommon malformation supposed to originate from a respiratory diverticulum arising from the ventral foregut. Morphologic appearance of GDCs is variable, depending on the density of their contents. GDCs are often misdiagnosed as solid masses by imaging techniques, and as a consequence they may be wrongly overtreated. We report our case of a 56-year-old man with a 5 cm hypoechoic mass of the gastroesophageal junction, incidentally detected by transabdominal ultrasonography. Neither transabdominal ultrasonography nor magnetic resonance clearly outlined the features of the lesion. The patient underwent endoscopic ultrasound (EUS), which showed a hypoechoic mass arising from the fourth layer of the anterior gastric wall, just below the gastroesophageal junction. According to EUS features, a diagnosis of gastrointestinal stromal tumor was suggested. EUS-guided fine-needle aspiration cytology revealed a diagnosis of GDC with pseudostratified columnar ciliated epithelium. We therefore performed an endoscopically-assisted laparoscopic excision of the cyst.

In conclusion, whenever a subepithelial gastric mass is found in the upper part of the gastric wall, a duplication cyst, although rare, should be considered. In this case, EUS-guided fine-needle aspiration cytology could provide a cytological diagnosis useful to arrange in advance the more adequate surgical treatment.