Combined contrast-enhanced power Doppler and real-time sonoelastography performed during EUS, used in the differential diagnosis of focal pancreatic masses (with videos)

Approach to Pancreatic Head Mass in the Background of Chronic Pancreatitis

Chronic pancreatitis (CP) is a known risk factor for pancreatic cancer. CP may present with an inflammatory mass, and differentiation from pancreatic cancer is often difficult. Clinical suspicion of malignancy dictates a need for further evaluation for underlying pancreatic cancer. Imaging modalities remain the mainstay of evaluation for a mass in background CP; however, they have their shortcomings. Endoscopic ultrasound (EUS) has become the go-to investigation. Adjunct modalities such as contrast-harmonic EUS and EUS elastography, as well as EUS-guided sampling using newer-generation needles are useful in differentiating inflammatory from malignant masses in the pancreas. Paraduodenal pancreatitis and autoimmune pancreatitis often masquerade as pancreatic cancer. In this narrative review, we discuss the various modalities used to differentiate inflammatory from malignant masses of the pancreas.

Approach to Pancreatic Head Mass in the Background of Chronic Pancreatitis

Chronic pancreatitis (CP) is a known risk factor for pancreatic cancer. CP may present with an inflammatory mass, and differentiation from pancreatic cancer is often difficult. Clinical suspicion of malignancy dictates a need for further evaluation for underlying pancreatic cancer. Imaging modalities remain the mainstay of evaluation for a mass in background CP; however, they have their shortcomings. Endoscopic ultrasound (EUS) has become the go-to investigation. Adjunct modalities such as contrast-harmonic EUS and EUS elastography, as well as EUS-guided sampling using newer-generation needles are useful in differentiating inflammatory from malignant masses in the pancreas. Paraduodenal pancreatitis and autoimmune pancreatitis often masquerade as pancreatic cancer. In this narrative review, we discuss the various modalities used to differentiate inflammatory from malignant masses of the pancreas.

Application of B-flow imaging and its enhanced mode in perforator mapping

AIM

To explore the value of B-flow (B-mode blood flow) imaging and its enhanced mode in perforator mapping.

MATERIALS AND METHODS

Before surgery, B-flow imaging, enhanced B-flow imaging, colour Doppler flow imaging (CDFI), and contrast-enhanced ultrasound (CEUS) were used to detect the skin-perforating vessels and small vessels in the fat layer of the donor site. Taking the intra-operative results as the reference standard, the diagnostic consistency and efficiency of the four modes were compared. Statistical analysis was performed using the Friedman M-test, Cochran's Q-test, and the Z-test.

RESULTS

Thirty flaps were excised, with 34 skin-perforating vessels and 25 non-skin-perforating vessels, as confirmed during surgery. In order of the number of skin-perforating vessels detected, the results showed that enhanced B-flow imaging detected more vessels than B-flow imaging and CDFI (all p<0.05), CEUS detected more vessels than B-flow imaging and CDFI (all p<0.05), B-flow imaging detected more vessels than CDFI (p<0.05). All four modes had remarkable and satisfactory diagnostic consistency and effectiveness, but B-flow imaging was the best (sensitivity 100%, specificity 92%, Youden index 0.92). In order of the number of small vessels in the fat layer detected, the results showed that enhanced B-flow imaging detected more vessels than CEUS, B-flow imaging, and CDFI (all p<0.05). CEUS detected more vessels than B-flow imaging and CDFI (all p<0.05).

CONCLUSION

B-flow imaging is an alternative method for perforator mapping. Enhanced B-flow imaging can reveal the microcirculation of flaps.

Pancreatic Cancer in Chronic Pancreatitis: Pathogenesis and Diagnostic Approach

Chronic pancreatitis is one of the main risk factors for pancreatic cancer, but it is a rare event. Inflammation and oncogenes work hand in hand as key promoters of this disease. Tobacco is another co-factor. During alcoholic chronic pancreatitis, the cumulative risk of cancer is estimated at 4% after 15 to 20 years. This cumulative risk is higher in hereditary pancreatitis: 19 and 12% in the case of PRSS1 and SPINK1 mutations, respectively, at an age of 60 years. The diagnosis is difficult due to: (i) clinical symptoms of cancer shared with those of chronic pancreatitis; (ii) the parenchymal and ductal remodeling of chronic pancreatitis rendering imaging analysis difficult; and (iii) differential diagnoses, such as pseudo-tumorous chronic pancreatitis and paraduodenal pancreatitis. Nevertheless, the occurrence of cancer during chronic pancreatitis must be suspected in the case of back pain, weight loss, unbalanced diabetes, and jaundice, despite alcohol withdrawal. Imaging must be systematically reviewed. Endoscopic ultrasound-guided fine-needle biopsy can contribute by targeting suspicious tissue areas with the help of molecular biology (search for KRAS, TP53, CDKN2A, DPC4 mutations). Short-term follow-up of patients is necessary at the clinical and paraclinical levels to try to diagnose cancer at a surgically curable stage. Pancreatic surgery is sometimes necessary if there is any doubt.

Contrast Enhanced EUS for Predicting Solid Pancreatic Neuroendocrine Tumor Grade and Aggressiveness

Pancreatic neuroendocrine tumor (PNET) behavior assessment is a daily challenge for physicians. Modern PNET management varies from a watch-and-wait strategy to surgery depending on tumor aggressiveness. Therefore, the aggressiveness definition plays a pivotal role in the PNET work-up. The aggressiveness of PNETs is mainly based on the dimensions and histological grading, with sometimes a lack of specificity and sensibility. In the last twenty years, EUS has become a cornerstone in the diagnostic phase of PNET management for its high diagnostic yield and the possibility of obtaining a histological specimen. The number of EUS applications in the PNET work-up has been rapidly increasing with new and powerful possibilities. The application of contrast has led to an important step in PNET detection; in recent years, it has been gaining interesting applications in aggressiveness assessment. In this review, we underline the latest experiences and opportunities in the behavior assessment of PNETs using contact-enhanced EUS and contested enhanced harmonic EUS with a particular focus on the future application and possibility that these techniques could provide.

The efficiency of contrast-enhanced endoscopic ultrasound (EUS) combined with EUS elastography for pancreatic cancer diagnosis: a systematic review and meta-analysis

PURPOSE

This study aimed to evaluate the performance characteristics of endoscopic ultrasound (EUS) elastography combined with contrast-enhanced EUS (CE-EUS) for the diagnosis of pancreatic malignancy among solid pancreatic lesions (SPLs).

METHODS

A comprehensive literature search using MEDLINE, Embase, and the Cochrane Library was performed from January 1991 through December 2020. The pooled performance characteristics, including sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (OR), were calculated using Meta-DiSc 1.4.

RESULTS

In total, 430 patients with 282 pancreatic malignancies were included in the metaanalysis. The pooled sensitivity, specificity, LR+, LR-, and diagnostic OR were 84% (95% confidence interval [CI], 80% to 88%), 85% (95% CI, 78% to 90%), 5.31 (95% CI, 2.57 to 10.97), 0.15 (95% CI, 0.07 to 0.34), and 67.72 (95% CI, 12.84 to 357.26) for the combination of CE-EUS and EUS elastography, respectively. In these same studies, the corresponding performance characteristics for EUS elastography were 87% (95% CI, 82% to 90%), 56% (95% CI, 48% to 64%), 2.28 (95% CI, 1.43 to 3.63), 0.12 (95% CI, 0.03 to 0.42), and 22.60 (95% CI, 5.81 to 87.92), respectively. In these same studies, the respective performance characteristics for CE-EUS were 84% (95% CI, 80% to 88%), 78% (95% CI, 70% to 84%), 3.80 (95% CI, 1.92 to 7.53), 0.13 (95% CI, 0.04 to 0.41), and 31.29 (95% CI, 6.12 to 159.87).

CONCLUSION

CE-EUS and EUS elastography are reliable supplemental techniques for the characterization of SPLs and diagnosis of pancreatic malignancies. However, more studies assessing the combined utilization of both procedures are needed.

The expanding role of endoscopic ultrasound elastography

Endoscopic ultrasound (EUS) is an invaluable tool for assessing various GI diseases. However, using just the conventional B-mode EUS imaging may not be sufficient to accurately delineate the lesion's character. Using the principle of stress-induced tissue strain, EUS elastography (EUS-E) can help in the real-time sonographic assessment of the level of tissue stiffness or hardness of any organ of interest during a routine EUS procedure. Thus, EUS-E can better characterize the lesion's nature and highlight the more suspicious areas within an individual lesion. The most commonly studied lesions with EUS-E are the pancreatic lesions, namely, chronic pancreatitis, pancreatic cancer, and lymph nodes. However, EUS-E is gradually expanding its use for lesion characterization of the liver, bile duct, adrenals, gastrointestinal tract, and even therapy response. Moreover, the use of EUS-E along with other image enhancement techniques such as harmonic EUS and contrast-enhanced EUS can improve the accuracy of the diagnosis. However, several technical aspects need to be standardized before EUS-E can be truly used as a tool for "virtual biopsy". This review focuses on the various technical aspects of the use of EUS-E, it is established and expanding indications and an extensive outline of the various studies on EUS-E. We also discuss the current pitfalls and future trends in EUS-E.

Enhanced endoscopic ultrasound imaging for pancreatic lesions: The road to artificial intelligence

Early detection of pancreatic cancer has long eluded clinicians because of its insidious nature and onset. Often metastatic or locally invasive when symptomatic, most patients are deemed inoperable. In those who are symptomatic, multi-modal imaging modalities evaluate and confirm pancreatic ductal adenocarcinoma. In asymptomatic patients, detected pancreatic lesions can be either solid or cystic. The clinical implications of identifying small asymptomatic solid pancreatic lesions (SPLs) of < 2 cm are tantamount to a better outcome. The accurate detection of SPLs undoubtedly promotes higher life expectancy when resected early, driving the development of existing imaging tools while promoting more comprehensive screening programs. An imaging tool that has matured in its reiterations and received many image-enhancing adjuncts is endoscopic ultrasound (EUS). It carries significant importance when risk stratifying cystic lesions and has substantial diagnostic value when combined with fine needle aspiration/biopsy (FNA/FNB). Adjuncts to EUS imaging include contrast-enhanced harmonic EUS and EUS-elastography, both having improved the specificity of FNA and FNB. This review intends to compile all existing enhancement modalities and explore ongoing research around the most promising of all adjuncts in the field of EUS imaging, artificial intelligence.

Role of endoscopic ultrasound elastography in differential diagnosis of pancreatic solid masses

Introduction: Endoscopic ultrasound (EUS) elastography is another technique that measures the stiffness of tissue and adds more diagnostic value to EUS.

Objective: This study aimed to assess the ability of qualitative and quantitative EUS elastography in differentiating malignant from benign solid pancreatic masses.

Methods: This 2-year cross-sectional study enrolled 80 patients with solid pancreatic masses in the department of endoscopy in Alassad University Hospital who underwent conventional and elastography-assisted EUS and then followed for pathology through EUS-guided or CT-guided biopsy or surgery.

Results: Qualitative elastography using a 5-point scoring system was able to recognize malignant pathology (obtained by EUS-guided biopsy, CT-guided biopsy, or surgery) with a sensitivity, specificity, and accuracy rates of 100%, 28.6%, and 81.3%, respectively. A quantitative method using hue histogram had a sensitivity of 71.2%–86.4% and specificity of 71.4%–81% with the best accuracy for histogram mean ratio (area under the curve, 0.867).

Conclusion: EUS elastography is a simple and good alternative method in differentiating malignant from benign pancreatic solid masses.

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.

The Asian Federation of Societies for Ultrasound in Medicine and Biology (AFSUMB) Guidelines for Contrast-Enhanced Endoscopic Ultrasound

The Asian Federation of Societies for Ultrasound in Medicine and Biology aimed to provide information on techniques and indications for contrast-enhanced harmonic endoscopic ultrasound (CH-EUS), and to create statements including the level of recommendation. These statements are based on current scientific evidence reviewed by a Consensus Panel of 15 internationally renowned experts. The reliability of clinical questions was measured by agreement rates after voting. Six statements were made on techniques, including suitable contrast agents for CH-EUS, differences between contrast agents, setting of mechanical index, dual imaging and duration and phases for observation. Thirteen statements were made on indications, including pancreatic solid masses, pancreatic cancer staging, pancreatic cystic lesions and mural nodules, detection of subtle pancreatic lesions, gallbladder sludge and polyps, hepatic lesions, lymph nodes, subepithelial lesions, visceral vascular diseases, guidance of fine needle aspiration and evaluation for local therapy. These international expert consensus guidelines will assist endosonographers in conducting CH-EUS according to evidence-based information.

Estimation of Accuracy of B-Mode Sonography and Elastography in Differentiation of Benign and Malignant Lymph Nodes With Cytology as Reference Standard: A Prospective Study

Purpose: To prospectively estimate the reliability of B-mode ultrasonography and sonoelastography in differentiating benign and malignant cervical lymph nodes with cytological findings as to the reference standard.

Materials and Methods: A total of 50 patients referred for sonography for enlarged cervical lymph nodes were included in the study. They were subjected initially to B-mode ultrasonography and sonoelastography and later underwent fine-needle aspiration cytology (FNAC) in the same sitting. Sensitivity, specificity, and accuracy were compared.

Results: Out of 50 cases, 33 were males, and 17 were females. On B-mode ultrasonography, 15 enlarged cervical lymph nodes were benign-looking and 35 were malignant-looking. When studied on elastography, 12 were benign-looking and 38 showed features of malignancy. However, when studied histopathologically, 18 were benign and 32 were malignant. The sensitivity, specificity, and diagnostic accuracy were compared, and the results were better in sonoelastography than B-mode ultrasonography. When both B-mode and sonoelastography were combined, an increase in the sensitivity for differentiation was achieved. However, a decrease in specificity was noted when both modalities were combined in our study, probably due to a significant number of patients with tuberculous cervical lymphadenopathy.

Conclusion: In countries like India, where granulomatous infection like tuberculosis is prevalent, the combination of sonoelastography with B-mode ultrasonography has decreased specificity in the differentiation of benign and malignant cervical lymph nodes, and histopathology is always needed for the final confirmation of diagnosis. The decreased specificity on elastography is attributed to simultaneous coexisting inflammation and fibrosis in chronic granulomatous lymphadenopathy.

Endoscopic ultrasound elastography for small solid pancreatic lesions with or without main pancreatic duct dilatation

BACKGROUND

/Objectives: Endoscopic ultrasound elastography (EUS-EG) is useful for diagnosis of small solid pancreatic lesions (SPLs), particularly in excluding pancreatic cancer (PC), but its dependence on main pancreatic duct dilatation (MPDD) has not been examined. We aimed to investigate EUS-EG for diagnosis of small SPLs with and without MPDD.

METHODS

Patients with pathologically diagnosed SPLs of ≤20 mm were included and retrospectively analyzed. Using the blue:green ratio, an EUS-EG image was classified as blue-dominant, equivalent, or green-dominant. Using multiple EUS-EG images per patient, a lesion with a greater number of blue-dominant than green-dominant images was classified as stiff, and the others as soft. EUS-EG images in random order were judged by three raters. Considering stiff SPLs as PC, diagnostic performance of EUS-EG was examined for SPLs with and without MPDD.

RESULTS

Of 126 cases analyzed, 65 (52%) were diagnosed as PC, and 63 (50%) had MPDD. A total of 1077 EUS-EG images were examined (kappa coefficient = 0.783). Lesions were classified as stiff in 91 cases and soft in 35 (kappa coefficient = 0.932). The ratio of stiff to soft lesions was significantly higher in PC than in non-PC (62:3 vs. 29:32, P < 0.001). The sensitivity, specificity, and negative predictive value of a stiff lesion with vs. without MPDD for diagnosis of PC were 94%, 23%, and 50% vs. 100%, 60%, and 100%, respectively.

CONCLUSIONS

Using the EUS-EG stiffness classification for small SPLs, PC can be excluded with high confidence and concordance for a soft lesion without MPDD.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Diagnosis of Pancreatic Cancer

Pancreatic cancer has the poorest prognosis among all cancers, and early diagnosis is essential for improving the prognosis. Along with radiologic modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), endoscopic modalities play an important role in the diagnosis of pancreatic cancer. This review evaluates the roles of two of those modalities, endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP), in the diagnosis of pancreatic cancer. EUS can detect pancreatic cancer with higher sensitivity and has excellent sensitivity for the diagnosis of small pancreatic cancer that cannot be detected by other imaging modalities. EUS may be useful for the surveillance of pancreatic cancer in high-risk individuals. Contrast-enhanced EUS and EUS elastography are also useful for differentiating solid pancreatic tumors. In addition, EUS-guided fine needle aspiration shows excellent sensitivity and specificity, even for small pancreatic cancer, and is an essential examination method for the definitive pathological diagnosis and treatment decision strategy. On the other hand, ERCP is invasive and performed less frequently for the purpose of diagnosing pancreatic cancer. However, ERCP is essential in cases that require evaluation of pancreatic duct stricture that may be early pancreatic cancer or those that require differentiation from focal autoimmune pancreatitis.

Contrast-Enhanced EUS for Differential Diagnosis of Pancreatic Masses: A Meta-Analysis

BACKGROUND

Though methods for the diagnosis of pancreatic masses are various, such as ultrasonography (US), computed tomography (CT), endoscopic ultrasonography (EUS), and contrast-enhanced computed tomography (CE-CT), their sensitivity, specificity, and accuracy are not quite satisfying. Contrast-enhanced endoscopic ultrasonography (CE-EUS), as a new technique, has its own unique advantages in diagnosing pancreatic disease. However, its sensitivity, specificity, and accuracy are still controversial.

OBJECTIVE

To evaluate the accuracy of CE-EUS for differential diagnosis between benign and malignant pancreatic mass lesions.

DESIGN

Eighteen relevant articles systemically searched from PubMed, Web of Science, Ovid, Scopus, and MEDLINE were selected. The pooled results were calculated in a fixed effects model.

MAIN OUTCOME MEASUREMENT

The pooled sensitivity, specificity, positive likelihood ratio (LR), negative likelihood ratio, diagnostic odds ratio (OR), and summary receiver operating characteristic (SROC) curve.

RESULTS

The pooled sensitivity, specificity, and diagnostic odds ratio of CE-EUS for the differential diagnosis of pancreatic adenocarcinomas were 0.91 (95% confidence interval (CI), 0.89-0.93), 0.86 (95% CI, 0.83-0.89), and 69.50 (95% CI, 48.89-98.80), respectively. The SROC area under the curve was 0.9545. The subgroup analysis based on excluding the outliers showed that the heterogeneity was eliminated and the pooled sensitivity and specificity were 0.92 (95% CI, 0.90-0.93) and 0.87 (95% CI, 0.84-0.89), respectively. The SROC area under the curve was 0.9569.

CONCLUSION

CE-EUS is a useful method to distinguish pancreatic adenocarcinoma from other pancreatic diseases. Compared with EUS elastography, it has higher specificity. However, it is still not superior to pathological diagnosis for the identification of pancreatic carcinomas.

Impact of endoscopic ultrasonography on diagnosis of pancreatic cancer

Accumulated evidence has revealed that endoscopic ultrasonography (EUS) has had a great impact on the clinical evaluation of pancreatic cancers. EUS can provide high-resolution images of the pancreas with a quality regarded as far surpassing that achieved on transabdominal ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI). EUS is particularly useful for the detection of small pancreatic lesions, while EUS and its related techniques such as contrast-enhanced EUS (CE-EUS), EUS elastography, and EUS-guided fine needle aspiration (EUS-FNA) are also useful in the differential diagnosis of solid or cystic pancreatic lesions and the staging (T-staging, N-staging, and M-staging) of pancreatic cancers. In the diagnosis of pancreatic lesions, CE-EUS and EUS elastography play a complementary role to conventional EUS. When sampling is performed using EUS-FNA, CE-EUS and EUS elastography provide information on the target lesions. Thus, conventional EUS, CE-EUS, EUS elastography, and EUS-FNA are essential in the clinical investigation of pancreatic cancer.

Discriminating chronic pancreatitis from pancreatic cancer: Contrast-enhanced EUS and multidetector computed tomography in direct comparison

BACKGROUND AND OBJECTIVES

To compare the ability of multidetector computed tomography (MDCT) and contrast-enhanced EUS to discriminate chronic pancreatitis (CP) from pancreatic ductal adenocarcinoma (PDAC).

SUBJECTS AND METHODS

A total of 215 patients (age: 62 ± 15 years, sex: f/m 80/135) were included in this retrospective study. All patients were examined by conventional endoscopic B-mode and contrast-enhanced high mechanical index EUS (CEHMI-EUS). CELMI-EUS was performed in 159 patients and endoscopic sonoelastography (ESE) in 210 patients. MDCT was carried out in 131 patients as part of their clinical work-up. Radiological reports were retrospectively analyzed. Final diagnosis was achieved by biopsy and evaluation of cytological specimens collected was performed by EUS-FNA, surgery, or follow-up of 12 months or more in patients with benign findings. In a subgroup of 100 patients, all diagnostic five methods were performed, and head-to-head analysis was performed.

RESULTS

Sensitivity and specificity for MDCT were 89% and 70% and for CEHMI-EUS were 96% and 91%, respectively. Sensitivities and specificities for EUS were 92% and 63% for B-Mode EUS, 96% and 38% for ESE, and 82% and 76% for CELMI-EUS, respectively. In the head-to-head analysis, each modality had shown lower numbers for specificity than shown in the overall group analysis because of high drop-out rate. EUS-FNA for PDAC had a sensitivity of 96% and a specificity of 100%.

CONCLUSIONS

Contrast-enhanced EUS is a reliable tool in discriminating PDAC from CP.

Endoscopic ultrasound elastography in the diagnosis of pancreatic masses: A meta-analysis

BACKGROUND AND AIMS

Endoscopic ultrasound (EUS) elastography is a novel non-invasive technique that can be used for distinguishing benign from malignant pancreatic masses. However, the studies have reported widely varied sensitivities and specificities. A meta-analysis was performed to assess the performance of EUS elastography for the differentiation of benign and malignant pancreatic masses.

METHODS

All the eligible studies were searched by PubMed, Medline, Embase, and the Cochrane Library. Sensitivity, specificity, positive likelihood ratio (LR), negative LR, and area under the curve (AUC) were calculated to examine the accuracy.

RESULTS

A total of nineteen studies which included 1687 patients were analyzed. The pooled sensitivity and specificity for the diagnosis of malignant pancreatic masses were 0.98 (95% confidence interval [CI] 0.96-0.99) and 0.63 (95% CI 0.58-0.69) for qualitative EUS elastography, 0.95 (95% CI 0.93-0.97) and 0.61 (95% CI 0.56-0.66) for quantitative EUS elastography, respectively. The positive and negative LR were 2.60 (95% CI 1.84-3.66) and 0.05 (95% CI 0.02-0.10) for qualitative EUS elastography, 2.64 (95% CI 1.82-3.82) and 0.10 (95% CI 0.06-0.16) for quantitative EUS elastography, respectively. The summary diagnostic odds ratio (DOR) and the AUC were 60.59 (95% CI 28.12-130.56) and 0.91 (Q* = 0.842) for qualitative EUS elastography, 30.09 (95% CI 15.40-58.76) and 0.93 (Q* = 0.860) for quantitative EUS elastography.

CONCLUSIONS

Our meta-analysis shows that both qualitative and quantitative EUS elastography have high accuracy in the detection of malignant pancreatic masses, which could be used as a valuable complementary method to EUS-FNA for the differentiation of pancreatic masses in the future.

Diagnostic accuracy of fine-needle aspiration of solid pancreatic lesions guided by endoscopic ultrasound elastography

BACKGROUND

Real-time elastography (RTE) may increase the diagnostic accuracy of fine-needle aspiration guided by endoscopic ultrasound. The aim of this study was to establish the diagnostic accuracy, sensitivity, and specificity of this combined methodological approach in a cohort of patients with solid pancreatic masses.

METHODS

We reviewed data from 54 patients with solid pancreatic lesions referred to our institution between January 2014 and June 2015. RTE, assessed in terms of strain ratio, was performed both qualitatively and semi-quantitatively, and a 25G needle was inserted into the most suspicious part of the lesion. Sensitivity, specificity, diagnostic accuracy, positive and negative predictive values were calculated.

RESULTS

The median lesion size was 35 mm (interquartile range: 25-43 mm). A diagnosis of adenocarcinoma was confirmed in 85.1% of cases. RTE, with a strain ratio cutoff of 4.21, showed a sensitivity of 86.9%, a specificity of 75%, and diagnostic accuracy of 85.1%. The diagnostic accuracy, sensitivity, and specificity of the combined methodology were 94.4%, 93.4%, and 100%, respectively. The positive predictive value was 100%, the negative predictive value 72.7% and the negative likelihood ratio 6.5. No severe adverse events were registered.

CONCLUSION

The combination of RTE with endoscopic ultrasound-guided fine-needle aspiration appears to be an efficient and safe technique for the characterization of solid pancreatic masses.

Advanced EUS Guided Tissue Acquisition Methods for Pancreatic Cancer

Pancreas cancer is a lethal cancer as the majority patients are diagnosed at an advanced incurable stage. Despite improvements in diagnostic modalities and management strategies, including surgery and chemotherapies, the outcome of pancreas cancer remains poor. Endoscopic ultrasound (EUS) is an important imaging tool for pancreas cancer. For decades, resected pancreas cancer and other cancer specimens have been used to identify tissue biomarkers or genomics for precision therapy; however, only 20% of patients undergo surgery, and thus, this framework is not useful for unresectable pancreas cancer. With advancements in needle technologies, tumor specimens can be obtained at the time of tissue diagnosis. Tumor tissue can be used for development of personalized cancer treatment, such as performing whole exome sequencing and global genomic profiling of pancreas cancer, development of tissue biomarkers, and targeted mutational assays for precise chemotherapy treatment. In this review, we discuss the recent advances in tissue acquisition of pancreas cancer.

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.

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.

Imaging modalities in the diagnosis of pancreatic adenocarcinoma: A systematic review and meta-analysis of sensitivity, specificity and diagnostic accuracy

BACKGROUND

Pancreatic cancer, primarily pancreatic ductal adenocarcinoma (PDAC), accounts for 2.4% of cancer diagnoses and 5.8% of cancer death annually. Early diagnoses can improve 5-year survival in PDAC. The aim of this systematic review was to determine the sensitivity, specificity and diagnostic accuracy values for MRI, CT, PET&PET/CT, EUS and transabdominal ultrasound (TAUS) in the diagnosis of PDAC.

METHODS

A systematic review was undertaken to identify studies reporting sensitivity, specificity and/or diagnostic accuracy for the diagnosis of PDAC with MRI, CT, PET, EUS or TAUS. Proportional meta-analysis was performed for each modality.

RESULTS

A total of 5399 patients, 3567 with PDAC, from 52 studies were included. The sensitivity, specificity and diagnostic accuracy were 93% (95% CI=88-96), 89% (95% CI=82-94) and 90% (95% CI=86-94) for MRI; 90% (95% CI=87-93), 87% (95% CI=79-93) and 89% (95% CI=85-93) for CT; 89% (95% CI=85-93), 70% (95% CI=54-84) and 84% (95% CI=79-89) for PET; 91% (95% CI=87-94), 86% (95% CI=81-91) and 89% (95% CI=87-92) for EUS; and 88% (95% CI=86-90), 94% (95% CI=87-98) and 91% (95% C=87-93) for TAUS.

CONCLUSION

This review concludes all modalities, except for PET, are equivalent within 95% confidence intervals for the diagnosis of PDAC.

A Multidisciplinary Approach to Pancreas Cancer in 2016: A Review

In this article, we review our multidisciplinary approach for patients with pancreatic cancer. Specifically, we review the epidemiology, diagnosis and staging, biliary drainage techniques, selection of patients for surgery, chemotherapy, radiation therapy, and discuss other palliative interventions. The areas of active research investigation and where our knowledge is limited are emphasized.

Differentiation of Pancreatic Masses via Endoscopic Ultrasound Strain Ratio Elastography Using Adjacent Pancreatic Tissue as the Reference

OBJECTIVES

The aims of this study were to evaluate diagnostic value of endoscopic ultrasound strain ratio elastography in patients with focal pancreatic masses and to determine the cutoff value between the pancreatic malignancies and inflammatory pancreatic masses using reference areas different than those used by other investigators.

METHODS

In a prospective single-center study, strain ratio was measured in patients with pancreatic masses. After the diagnosis was established, statistical analysis was used to compare the group with pancreatic malignancies to the one with inflammatory masses.

RESULTS

Strain ratio cutoff of 7.59 provided 100% sensitivity, 95% specificity, and 97% overall accuracy for differentiation of patients with pancreatic malignancies from those with inflammatory masses.

CONCLUSIONS

Our data show high sensitivity and specificity for the calculated strain ratio. Adjacent normal pancreatic tissue is adequate as a reference area based on the inclusion criteria. Diverse cutoff values and standardization of methods in the studies published so far require further investigations, before the implementation of the method in a routine clinical practice becomes possible.

Maximizing the endosonography: The role of contrast harmonics, elastography and confocal endomicroscopy

New technologies in endoscopic ultrasound (EUS) evaluation have been developed because of the need to improve the EUS and EUS-fine needle aspiration (EUS-FNA) diagnostic rate. This paper reviews the principle, indications, main literature results, limitations and future expectations for each of the methods presented. Contrast-enhanced harmonic EUS uses a low mechanical index and highlights slow-flow vascularization. This technique is useful for differentiating solid and cystic pancreatic lesions and assessing biliary neoplasms, submucosal neoplasms and lymph nodes. It is also useful for the discrimination of pancreatic masses based on their qualitative patterns; however, the quantitative assessment needs to be improved. The detection of small solid lesions is better, and the EUS-FNA guidance needs further research. The differentiation of cystic lesions of the pancreas and the identification of the associated malignancy features represent the main indications. Elastography is used to assess tissue hardness based on the measurement of elasticity. Despite its low negative predictive value, elastography might rule out the diagnosis of malignancy for pancreatic masses. Needle confocal laser endomicroscopy offers useful information about cystic lesions of the pancreas and is still under evaluation for use with solid pancreatic lesions of lymph nodes.

The clinical impact of ultrasound contrast agents in EUS: a systematic review according to the levels of evidence

BACKGROUND AND AIMS

The use of contrast-harmonic EUS (CH-EUS) in routine clinical practice is increasing rapidly but is not yet standardized. We present the levels of evidence (LEs) found in the literature to put its clinical outcomes in the appropriate perspective.

METHODS

We conducted a systematic review of the available English-language articles. The LEs were stratified according to the Oxford Centre for Evidence-Based Medicine guidelines.

RESULTS

Overall, 210 articles were included and presented according to different pathologic conditions. For pancreatic solid neoplasms, the pooled sensitivity and specificity in the diagnosis of pancreatic carcinoma were very high (LE 1); quantitative analysis and guidance of FNA were reported as investigational research (LE 2-3). For pancreatic cystic lesions, the identification of neoplastic solid components as hyperenhanced lesions represented a promising application of CH-EUS (LE 2). For lymph nodes, CH-EUS increased the diagnostic yield of B-mode EUS for the detection of malignancy (LE 2). For submucosal tumors, CH-EUS seemed useful for differential diagnosis and risk stratification (LE 2-3). For other applications, differential diagnosis of gallbladder and vascular abnormalities by CH-EUS were reported (LE 2-3).

CONCLUSIONS

The LEs of CH-EUS in the literature have evolved from the initial descriptive studies to multicenter and prospective trials, and even meta-analyses. The differential diagnosis between benign and malignant lesions is the main field of application of CH-EUS. With regard to pancreatic solid neoplasms, the concomitant use of both CH-EUS and EUS-FNA may have additive value in increasing the overall accuracy by overcoming the false-negative results associated with each individual technique. Other applications are promising but still investigational.

Differential diagnosis of solid pancreatic masses: contrast-enhanced harmonic (CEH-EUS), quantitative-elastography (QE-EUS), or both?

BACKGROUND

Contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) and quantitative-elastography endoscopic ultrasound (QE-EUS) are considered useful tools for the evaluation of solid pancreatic tumors (SPT). The aim of our study was to evaluate the diagnostic accuracy of CEH-EUS, QE-EUS, and the combination of both for the differential diagnosis of SPT.

METHODS

Sixty-two consecutive patients (mean age 64.3 years, range 32-89 years, 44 male) who underwent EUS for the evaluation of SPT were prospectively included. EUS was performed with a linear Pentax-EUS and a Hitachi-Preirus processor. The mass (area A) and a reference area B were selected during QE-EUS, and results expressed as B/A (strain ratio). A strain histogram of the mass was also evaluated. Microvascularization of the tumor was evaluated over 2 min during CEH-EUS after intravenous injection of 4.8 mL SonoVue. Final diagnosis was based on histopathology of surgical specimens or EUS-guided tissue acquisition and clinical follow-up in non-operated cases. Diagnostic accuracy of CEH-EUS, QE-EUS, and their combination was calculated.

RESULTS

Median size of the masses was 32 mm (range 12-111). Final diagnosis was pancreatic adenocarcinoma (n = 45), neuroendocrine tumor (n = 3), inflammatory mass (n = 10), pancreatic metastasis (n = 2), autoimmune pancreatitis (n = 1), and a mucinous cystadenocarcinoma (n = 1). Overall accuracies for determination of malignancy using QE-EUS, CEH-EUS, their combination, and EUS-guided tissue acquisition were 98.4% (95% confidence interval (CI): 91.4-99.7), 85.5% (95% CI: 74.7-92.2), 91.9% (95% CI: 82.5-96.5), and 91.5% (95% CI: 83.6-99.5), respectively.

CONCLUSION

The combination of QE-EUS and CEH-EUS is a useful tool for the differential diagnosis of SPT, giving complementary information. However, this combination does not significantly increase the diagnostic accuracy of either of the techniques performed alone.

New endoscopic ultrasonography techniques for pancreaticobiliary diseases

Endoscopic ultrasonography (EUS) is widely used to evaluate pancreaticobiliary diseases, especially pancreatic masses. EUS has a good ability to detect pancreatic masses, but it is not sufficient for the differential diagnosis of various types of lesions. In order to address the limitations of EUS, new techniques have been developed to improve the characterization of the lesions detected by EUS. EUS-guided fine needle aspiration (EUS-FNA) has been used for diagnosing pancreatic tumors. In order to improve the histological diagnostic yield, a EUS-FNA needle with a core trap has recently been developed. Contrast-enhanced harmonic EUS is a new imaging modality that uses an ultrasonographic contrast agent to visualize blood flow in fine vessels. This technique is useful in the diagnosis of pancreatic solid lesions and in confirming the presence of vascularity in mural nodules for cystic lesions. EUS elastography analyzes several different variables to measure tissue elasticity, color patterns, and strain ratio, using analytical techniques such as hue-histogram analysis, and artificial neural networks, which are useful for the diagnosis of chronic pancreatitis and pancreatic cancer.

Contrast-enhanced harmonic endoscopic ultrasonography for assessment of lymph node metastases in pancreatobiliary carcinoma

AIM: To assess the usefulness of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for lymph node metastasis in pancreatobiliary carcinoma.

METHODS: All patients suspected of pancreatobiliary carcinoma with visible lymph nodes after standard EUS between June, 2009 and January, 2012 were enrolled. In the primary analysis, patients with successful EUS-fine needle aspiration (FNA) were included. The lymph nodes were assessed by several standard EUS variables (short and long axis lengths, shape, edge characteristic and echogenicity), color Doppler EUS variable [central intranodal blood vessel (CIV) presence] and CH-EUS variable (heterogeneous/homogeneous enhancement patterns). The diagnostic accuracy relative to EUS-FNA was calculated. In the second analysis, N-stage diagnostic accuracy of CH-EUS was compared with EUS-FNA in patients who underwent surgical resection.

RESULTS: One hundred and nine patients (143 lymph nodes) fulfilled the criteria. The short axis cut-off ≥ 13 mm predicted malignancy with a sensitivity and specificity of 72% and 85%, respectively. These values were 72% and 63% for the long axis cut-off ≥ 20 mm, 62% and 75% for the round shape variable, 81% and 30% for the sharp edge variable, 66% and 61% for the hypoechogenicity variable, 70% and 72% for the CIV-absent variable, and 83% and 91% for the heterogeneous CH-EUS-enhancement variable, respectively. CH-EUS was more accurate than standard and color Doppler EUS, except the short axis cut-off. Notably, three patients excluded because of EUS-FNA failure were correctly N-staged by CH-EUS.

CONCLUSION: CH-EUS complements standard and color Doppler EUS and EUS-FNA for assessment of lymph node metastases.

The role of contrast-enhanced endoscopic ultrasound in pancreatic adenocarcinoma

Contrast-enhanced endoscopic ultrasound (CE-EUS) allows characterization, differentiation, and staging of focal pancreatic masses. The method has a high sensitivity and specificity for the diagnosis of pancreatic adenocarcinoma which is visualized as hypo-enhanced as compared to the rest of the parenchyma while chronic pancreatitis and neuroendocrine tumors are generally either iso-enhanced or hyper-enhanced. The development of contrast-enhanced low mechanical index harmonic imaging techniques used in real time during endoscopic ultrasound (EUS) allowed perfusion imaging and the quantification of intensity of the contrast signal through time-intensity curve analysis. Thus, contrast harmonic imaging-EUS has been used to differentiate pancreatic adenocarcinoma based on lower values of the peak enhancement. Future applications of CE-EUS in pancreatic adenocarcinoma include not only use of targeted contrast agents for early detection, tridimensional and fusion techniques for enhanced staging and resectability assessment but also novel applications of perfusion imaging for monitoring ablative therapy, improved local detection through EUS-guided sampling of portal vein flow or enhanced drug delivery through sonoporation and ultrasound-induced release of the drugs locally.

Endoscopic ultrasound for staging of colonic cancer proximal to the rectum: A systematic review and meta-analysis

Background and Objectives:

Treatment of colonic cancer patients is highly dependent on the depth of tumor invasion (T-stage) as well as the extension of lymph node involvement (N-stage). We aimed to systematically review the accuracy of endoscopic ultrasound (EUS) for staging of colonic cancer proximal to the rectum.

Patients and Methods:

Men and women with colonic adenocarcinomas were included in the study. EUS staging was compared to histopathology as the gold standard. Outcome measures were T- and N-staging accuracies. Articles were searched in PubMed, Web of Science, The Cochrane Library, and EMBASE.

Results:

Six studies were identified comparing EUS staging of colonic cancer to histopathology. The pooled-staging sensitivity and specificity were 0.90 and 0.98 for T1 tumors, 0.67 and 0.96 for T2 tumors, and 0.97 and 0.83 for T3/T4 tumors, respectively. Sensitivity and specificity for N + disease were 0.59 and 0.78, respectively.

Conclusions:

EUS is a feasible method for T-staging of cancers of the colon proximal to the rectum. The accuracy of lymph node staging needs to be verified by prospective multicenter studies including larger patient populations.

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 EUS-fine 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.

Quantitative contrast-enhanced harmonic EUS in differential diagnosis of focal pancreatic masses (with videos)

BACKGROUND

The role of EUS with contrast agents can be expanded through the use of time-intensity curve (TIC) analysis and computer-aided interpretation.

OBJECTIVE

To validate the use of parameters derived from TIC analysis in an artificial neural network (ANN) classification model designed to diagnose pancreatic carcinoma (PC) and chronic pancreatitis (CP).

SETTING

Prospective, multicenter, observational trial-endoscopy units from Romania, Denmark, Germany, and Spain.

PATIENTS

A total of 167 consecutive patients with PC or CP.

INTERVENTIONS

Contrast-enhanced harmonic EUS (CEH-EUS) and EUS-guided FNA (EUS-FNA), TIC analysis, and ANN processing.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, positive and negative predictive values (PPV, NPV) for EUS-FNA, CEH-EUS, and the ANN.

RESULTS

After excluding all of the recordings that did not meet the technical and procedural criteria, 112 cases of PC and 55 cases of CP were included. EUS-FNA was performed in 129 patients, and the diagnosis was confirmed by surgery (n = 15) or follow-up (n = 23) in the remaining cases. Its sensitivity and specificity were 84.82% and 100%, respectively, whereas the PPV and NPV were 100% and 76.63%, respectively. The sensitivity of real-time quantitative assessment of CEH-EUS was 87.5%, specificity 92.72%, PPV 96.07%, and NPV 78.46%. Peak enhancement, wash-in area under the curve, wash-in rate, and the wash-in perfusion index were significantly different between the groups. No significant differences were found between rise time, mean transit time, and time to peak. For the ANN, sensitivity was 94.64%, specificity 94.44%, PPV 97.24%, and NPV 89.47%.

LIMITATIONS

Only PC and CP lesions were included.

CONCLUSION

Parameters obtained through TIC analysis can differentiate between PC and CP cases and can be used in an automated computer-aided diagnostic system with good diagnostic results. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01315548.).

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.

JSUM ultrasound elastography practice guidelines: pancreas

Ultrasound elastography is a relatively new diagnostic technique for measuring the elasticity (hardness) of tissue. Eleven years have passed since the debut of elastography. Various elastography devices are currently being marketed by manufacturers under different names. Pancreatic elastography can be used not only with transabdominal ultrasonography but also with endoscopic ultrasonography, but some types of elastography are difficult to perform for the pancreas. These guidelines aim to classify the various types of elastography into two major categories depending on the differences in the physical quantity (strain, shear wave), and to present the evidence for pancreatic elastography and how to use pancreatic elastography in the present day. But the number of reports on ultrasound elastography for the pancreas is still small, and there are no reports on some elastography devices for the pancreas. Therefore, these guidelines do not recommend methods of imaging and analysis by elastography device.

Neoplasia in chronic pancreatitis: how to maximize the yield of endoscopic ultrasound-guided fine needle aspiration

When performing endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), identifying neoplasia in the setting of chronic pancreatitis can be technically challenging. The morphology of an ill-defined mass on sonography, presence of calcifications or intervening collaterals, reverberation from a biliary stent, low yield of tissue procurement, and interpretative errors in cytopathology can result in both false-negative and false-positive results. Although these challenges cannot be completely eliminated, elastography or contrast-enhanced imaging can aid in differentiating an inflammatory mass from a neoplasm. Also, performing more passes of FNA, procuring core biopsy material, performing rapid onsite evaluation, conducting ancillary pathology studies, and even repeating the procedure on a different day can aid in improving the diagnostic performance of EUS-FNA. This review provides a concise update and offers practical tips to improving the diagnostic yield of EUS-FNA when sampling solid pancreatic mass lesions in the setting of chronic pancreatitis.

Role of endoscopy in the diagnosis of autoimmune pancreatitis and immunoglobulin G4-related sclerosing cholangitis

Autoimmune pancreatitis (AIP) must be differentiated from pancreatic carcinoma, and immunoglobulin (Ig)G4-related sclerosing cholangitis (SC) from cholangiocarcinoma and primary sclerosing cholangitis (PSC). Pancreatographic findings such as a long narrowing of the main pancreatic duct, lack of upstream dilatation, skipped narrowed lesions, and side branches arising from the narrowed portion suggest AIP rather than pancreatic carcinoma. Cholangiographic findings for PSC, including band-like stricture, beaded or pruned-tree appearance, or diverticulum-like outpouching are rarely observed in IgG4-SC patients, whereas dilatation after a long stricture of the bile duct is common in IgG4-SC. Transpapillary biopsy for bile duct stricture is useful to rule out cholangiocarcinoma and to support the diagnosis of IgG4-SC with IgG4-immunostaining. IgG4-immunostaining of biopsy specimens from the major papilla advances a diagnosis of AIP. Contrast-enhanced endoscopic ultrasonography (EUS) and EUS elastography have the potential to predict the histological nature of the lesions. Intraductal ultrasonographic finding of wall thickening in the non-stenotic bile duct on cholangiography is useful for distinguishing IgG4-SC from cholangiocarcinoma. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is widely used to exclude pancreatic carcinoma. To obtain adequate tissue samples for the histological diagnosis of AIP, EUS-Tru-cut biopsy or EUS-FNA using a 19-gauge needle is recommended, but EUS-FNA with a 22-gauge needle can also provide sufficient histological samples with careful sample processing after collection and rapid motion of the FNA needles within the pancreas. Validation of endoscopic imaging criteria and new techniques or devices to increase the diagnostic yield of endoscopic tissue sampling should be developed.

Applications of endoscopic ultrasound in pancreatic cancer

Since the introduction of endoscopic ultrasound guided fine-needle aspiration (EUS-FNA), EUS has assumed a growing role in the diagnosis and management of pancreatic ductal adenocarcinoma (PDAC). The objective of this review is to discuss the various applications of EUS and EUS-FNA in PDAC. Initially, its use for detection, diagnosis and staging will be described. EUS and EUS-FNA are highly accurate modalities for detection and diagnosis of PDAC, this high accuracy, however, is decreased in specific situations particularly in the presence of chronic pancreatitis. Novel techniques such as contrast-enhanced EUS, elastography and analysis of DNA markers such as k-ras mutation analysis in FNA samples are in progress and might improve the accuracy of EUS in the detection of PDAC in this setting and will be addressed. EUS and EUS-FNA have recently evolved from a diagnostic to a therapeutic technique in the management of PDAC. Significant developments in therapeutic EUS have occurred including advances in celiac plexus interventions with direct injection of ganglia and improved pain control, EUS-guided fiducial and brachytherapy seed placement, fine-needle injection of intra-tumoral agents and advances in EUS-guided biliary drainage. The future role of EUS and EUS in management of PDAC is still emerging.

Can elastography replace fine needle aspiration?

Endoscopic ultrasound (EUS) is one of the best diagnostic methods for diseases of the digestive tract and surrounding organs. Whereas EUS-guided fine needle aspiration (FNA) has been very useful for providing histological confirmation for previously hard to reach lesions, elastography is aiming to obtain a “virtual biopsy” by assessing differences in elasticity between the normal and pathological – usually malignant – tissue. A question that arises is whether EUS-elastography has reached a stage where it might successfully supplant the use of EUS-FNA in some of its clinical indications. The main indications of EUS-guided FNA are listed in this article and published data on the usage of elastography in these settings is reviewed for each one. In some of the indications, a plethora of studies have been published, notably for the evaluation of solid pancreatic masses and lymph nodes, while in others there is little relevant data (submucosal masses, left liver lesions, left adrenal masses), or elastography simply is not suitable as a diagnostic means (cystic lesions). Our conclusion is that elastography is not yet ready to replace EUS-FNA in its indications, but should complement it in various settings, especially for the assessment of lymph nodes. It can only be considered an alternative on a case-by-case basis, in situations where FNA is regarded as a contraindication. Furthermore, it could be used in conjunction with other imaging techniques, such as contrast-enhanced EUS, in order to further improve the accuracy of non-invasive EUS assessment, possibly making the case for a more limited or targeted use of EUS-FNA in selected cases.

Yield of Contrast-Enhanced Power Doppler Endoscopic Ultrasonography and Strain Ratio Obtained by EUS-Elastography in the Diagnosis of Focal Pancreatic Solid Lesions

OBJECTIVE

Although endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is the gold standard for diagnosing pancreatic lesions, its negative predictive value is suboptimal. Our aim was to evaluate the yield of contrast-enhanced EUS (CED-EUS) and of strain ratio EUS-elastography (SR-E-EUS) for differentiating pancreatic solid lesions.

METHODS

Forty-seven patients (27 men, 20 women, 70 ± 11 years) were consecutively involved in this single-center, prospective study. They were submitted to EUS, SR-E-EUS, CED-EUS with Sonovue(®), and EUS-FNA. The final diagnosis was based on the histological assessment of EUS-FNA and/or surgical specimens when available, and on follow-up of at least 6 months.

RESULTS

From the 47 focal pancreatic lesions included, 13 (28%) were benign and 34 (72%) malignant. Patients with malignancy were older (70 ± 11 vs. 61 ± 8, P = 0.003), and had larger lesions (34 ± 12 mm vs. 22 ± 11 mm, P = 0.03). Malignant lesions had higher SR-E-EUS (31 ± 32 vs. 8 ± 9, P = 0.001) and more hypovascular pattern (93% vs. 33%, P < 0.001). Logistic regression determined that only hypovascularity (OR = 2.6, 95%CI: 1.5-130, P = 0.02) was independently predictive of malignancy. ROC analysis for SR-E-EUS yielded an optimal cutoff of 8 (AUC 0.91, 95%CI: 0.74-0.98) for the best power distinction for malignancy. There was no significant difference concerning sensitivity (79%, 90%, 93%) and specificity rates (85%, 75%, 67%) of EUS-FNA, SR-E-EUS, and CED-EUS, respectively. By analysis of the inconclusive EUS-FNA subset (9 patients, 19%), SR-E-EUS > 8 and hypovascularity showed sensitivity of 80% and 100%, and specificity of 67% and 67%, respectively.

CONCLUSION

The clinical utility of CED-EUS and SR-E-EUS remains questionable. The accuracies of CED-EUS and SR-E-EUS are similar to EUS-FNA. Hypovascularity was independently predictive of malignancy. Patients with inconclusive EUS-FNA could benefit from CED-EUS due to the high sensitivity of hypovascularity for diagnosing malignancy.

Power Doppler endoscopic ultrasound for the assessment of pancreatic neuroendocrine tumors

OBJECTIVE

Pancreatic neuroendocrine tumors (PNET) represent rare, heterogeneous tumors with clinical, imaging and treatment particularities. The aim of this study was to assess the role of power Doppler endoscopic ultrasound (EUS) in the diagnosis and characterization of PNET.

METHODS

All consecutive patients with PNET assessed by power Doppler EUS in the Research Centre of Gastroenterology and Hepatology Craiova, Romania, in the past 51 months were included in the study. All EUS examinations were performed initially in gray-scale mode, followed by power Doppler mode examinations, before and after contrast-enhancement. Each recorded EUS movie was further subjected to post-processing using a computer-enhanced dynamic analysis using a special plug-in which permitted assessment of vascularity index (EUS-VI).

RESULTS

Based on the analysis of all consecutive malignant focal pancreatic masses diagnosed in the study period, a total number of 131 consecutive patients were included: 14 patients with pancreatic neuroendocrine tumors and 117 patients with pancreatic adenocarcinoma. The sensitivity of the pre-contrast EUS-VI for the diagnosis of PNET was 71.43%, similar to EUS-FNA. After contrast enhancement, the EUS-VI is also higher in PNET (27.07%) as compared to pancreatic adenocarcinoma where it was significantly lower 9.82% (P < 0.001). However, the sensitivity of EUS-VI after contrast enhancement for the diagnosis of PNET was 100%, higher than pre-contrast EUS-VI, with an acceptable specificity (79.49%) and better accuracy (81.68%).

CONCLUSION

Power Doppler EUS represents a useful method in the initial assessment of PNET. Using evaluation of vascularity through EUS-VI, the differentiation between PNET and pancreatic cancer could be possible, especially in the subgroup of patients where EUS-guided fine needle aspiration is falsely negative.

Pancreatic head cancer in patients with chronic pancreatitis

BACKGROUND

Chronic pancreatitis (CP) is a risk factor of pancreatic adenocarcinoma (PA). The discovery of a pancreatic head lesion in CP frequently leads to a pancreaticoduodenectomy (PD) which preceded by a multidisciplinary meeting (MM). The aim of this study was to evaluate the relevance between this indication of PD and the definitive pathological results.

METHODS

Between 2000 and 2010, all patients with CP who underwent PD for suspicion of PA without any histological proof were retrospectively analyzed. The operative decision has always been made at an MM. The definitive pathological finding was retrospectively confronted with the decision made at an MM, and patients were classified in two groups according to this concordance (group 1) or not (group 2). Clinical and biological parameters were analyzed, preoperative imaging were reread, and confronted to pathological findings in order to identify predictive factors of malignant degeneration.

RESULTS

During the study period, five of 18 (group 1) patients with CP had PD were histologically confirmed to have PA, and the other 13 (group 2) did not have PA. The median age was 52.5+/-8.2 years (gender ratio 3.5). The main symptoms were pain (94.4%) and weight loss (72.2%). There was no patient's death. Six (33.3%) patients had a major complication (Clavien-Dindo classification ≥ 3). There was no statistical difference in clinical and biological parameters between the two groups. The rereading of imaging data could not detect efficiently all patients with PA.

CONCLUSIONS

Our results confirmed the difficulty in detecting malignant transformation in patients with CP before surgery and therefore an elevated rate of unnecessary PD was found. A uniform imaging protocol is necessary to avoid PD as a less invasive treatment could be proposed.

Key endoscopic ultrasound features of pancreatic ductal adenocarcinoma smaller than 20 mm

BACKGROUND AND STUDY AIMS. Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis compared with other solid pancreatic tumors. Diagnosis of PDAC in the earliest possible stage is important to improve the prognosis. Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been the gold-standard modality for diagnosing pancreatic lesions, its diagnostic yield is not satisfactory for pancreatic tumors smaller than 20 mm. The purpose of this study was to determine the EUS findings that are useful for differentiating PDAC from other solid pancreatic tumors when the lesions are smaller than 20 mm. PATIENTS AND METHODS. We performed a retrospective review of 126 patients with pancreatic tumors smaller than 20 mm who had undergone EUS. According to the final pathological diagnoses, they were categorized into either the PDAC or non-PDAC group. We, then, compared the EUS findings between the two groups. RESULTS. Among the 126 patients, we diagnosed PDAC in 75 patients and non-PDAC in the remaining patients, including neuroendocrine tumor in 43 patients, intraductal papillary mucinous carcinoma in 3 patients, solid pseudopapillary neoplasm in 2 patients, and inflammatory pseudotumor in 3 patients. Of all EUS findings, three factors were significantly indicative of PDAC: an irregular tumor edge, main pancreatic duct dilation, and tumor location in the pancreatic head. The predicted probability for PDAC was 80%, 92.6%, and 74.1%, respectively. CONCLUSIONS. EUS could be a useful modality for differentiating PDAC from other solid pancreatic tumors, when the diagnostic yield of EUS-FNA is unsatisfactory, even for lesions smaller than 20 mm.

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.

Endoscopic ultrasound elastography for differentiating between pancreatic adenocarcinoma and inflammatory masses: A meta-analysis

AIM: To evaluate the accuracy of endoscopic ultrasound (EUS) elastography for differentiating between pancreatic ductal adenocarcinoma (PDAC) and pancreatic inflammatory masses (PIM).

METHODS: Electronic databases (updated to December 2012) and manual bibliographical searches were carried out. A meta-analysis of all diagnostic clinical trials evaluating the accuracy of EUS elastography in differentiating PDAC from PIM was conducted. Heterogeneity was assessed among the studies. The meta-analysis was performed to evaluate the accuracy of EUS elastography in differentiating PDAC from PIM in homogeneous studies.

RESULTS: Ten studies involving 781 patients were included in the analysis. Significant heterogeneity in sensitivity was observed among the studies (Cochran Q test = 24.16, df = 9, P = 0.0041, I² = 62.8%), while heterogeneity in specificity was not observed (Cochran Q test = 5.93, df = 9, P = 0.7473, I² = 0.0%). The area under the curve under the Sports Rights Owners Coalition was 0.8227. Evaluation of heterogeneity suggested that the different diagnostic standards used in the included studies were the source of heterogeneity. In studies using the color pattern as the diagnostic standard, the pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR and diagnostic OR were 0.99 (0.97-1.00), 0.76 (0.67-0.83), 3.36 (2.39-4.72), 0.03 (0.01-0.07) and 129.96 (47.02-359.16), respectively. In studies using the hue histogram as the diagnostic standard, the pooled sensitivity, specificity, positive LR, negative LR and diagnostic OR were 0.92 (0.89-0.95), 0.68 (0.57-0.78), 2.84 (2.05-3.93), 0.12 (0.08-0.19) and 24.69 (12.81-47.59), respectively.

CONCLUSION: EUS elastography is a valuable method for the differential diagnosis between PDAC and PIM. And a preferable diagnostic standard should be explored and improvements in specificity are required.