Linear endoscopic ultrasound evaluation of hepatic veins

Liver resection surgery can be associated with significant perioperative mortality and morbidity. Extensive knowledge of the vascular anatomy is essential for successful, uncomplicated liver surgeries. Various imaging techniques like multidetector computed tomographic and magnetic resonance angiography are used to provide information about hepatic vasculature. Linear endoscopic ultrasound(EUS) can offer a detailed evaluation of hepatic veins, help in assessment of liver segments and can offer a possible route for EUS guided vascular endotherapy involving hepatic veins. A standard technique for visualization of hepatic veins by linear EUS has not been described. This review paper describes the normal EUS anatomy of hepatic veins and a standard technique for visualization of hepatic veins from four stations. With practice an imaging of all the hepatic veins is possible from four stations. The imaging from fundus of stomach is the easiest and most convenient method of imaging of hepatic veins. EUS of hepatic vein and the tributaries is an operator dependent technique and in expert hands may give a mapping comparable to computed tomographic and magnetic resonance imaging. EUS of hepatic veins can help in identification of individual sectors and segments of liver. EUS guided interventions involving hepatic veins may require approach from different stations.     

CLINICAL USEFULNESS OF NEWLY DEVELOPED ELECTRONIC 360° RADIAL ENDOSCOPIC ULTRASONOGRAPHY

After the development of the mechanical radial scanning echoendoscope by Olympus Medical Systems (Tokyo, Japan), endoscopic ultrasonography (EUS) has become an indispensable examination in the clinical fields. Although mechanical radial EUS has no Doppler function because of its scanning method, Olympus Medical Systems developed a new electronic 360° radial EUS in 2003. Newly developed electronic radial EUS provides better penetration, fewer artifacts, color Doppler and power Doppler function, and tissue harmonic imaging. Its maneuverability is nearly the same as conventional mechanical radial EUS. With Doppler function it is easy to differentiate solid tumors such as pancreatic cancer, islet tumor etc., and to diagnose vascular invasion. Although there are some problems, electronic radial EUS has a promising future and it is believed that electronic radial EUS will become the standard model for the next generation of EUS equipment in imaging diagnosis.     

ENDOSCOPIC ULTRASOUND STAGING OF PANCREATIC CANCER

The pancreatic cancer tumor remains difficult to cure in its advanced form making early diagnosis and accurate staging essential. There is debate regarding the single best diagnostic or staging modality as well as the best approach in imaging patients with pancreatic cancer. Methods: The recent literature regarding the staging of patients with pancreatic cancer was reviewed. Special attention was directed to comparative trials of imaging modalities that included endoscopic ultrasonography (EUS). Results: EUS accuracy ranges from 78–94% for pancreatic tumor staging and from 64–82% for nodal staging. EUS remains the most sensitive imaging modality for small pancreatic tumors. Conclusion: EUS remains the preferred imaging modality in many patients with pancreatic cancer by virtue of its ability to detect even the smallest lesions, determine the presence of vascular involvement, and acquire tissue of primary tumors, lymph nodes and distant metastases. Continued advances in ultrasound imaging and fine needle aspiration techniques will improve the yield of EUS. Interventional applications of EUS in patients with pancreatic tumors will provide an expanding role for EUS in the future.     

Contrast-enhanced harmonic endoscopic ultrasound imaging: Basic principles,present situation and future perspectives

Over the last decade, the development of stabilised microbubble contrast agents and improvements in available ultrasonic equipment, such as harmonic imaging, have enabled us to display microbubble enhancements on a greyscale with optimal contrast and spatial resolution. Recent technological advances made contrast harmonic technology available for endoscopic ultrasound (EUS) for the first time in 2008. Thus, the evaluation of microcirculation is now feasible with EUS, prompting the evolution of contrast-enhanced EUS from vascular imaging to images of the perfused tissue. Although the relevant experience is still preliminary, several reports have highlighted contrast-enhanced harmonic EUS (CH-EUS) as a promising noninvasive method to visualise and characterise lesions and to differentiate benign from malignant focal lesions. Even if histology remains the gold standard, the combination of CH-EUS and EUS fine needle aspiration (EUS-FNA) can not only render EUS more accurate but may also assist physicians in making decisions when EUS-FNA is inconclusive, increasing the yield of EUS-FNA by guiding the puncture with simultaneous imaging of the vascularity. The development of CH-EUS has also opened up exciting possibilities in other research areas, including monitoring responses to anticancer chemotherapy or to ethanol-induced pancreatic tissue ablation, anticancer therapies based on ultrasound-triggered drug and gene delivery, and therapeutic adjuvants by contrast ultrasound-induced apoptosis. Contrast harmonic imaging is gaining popularity because of its efficacy, simplicity and non-invasive nature, and many expectations are currently resting on this technique. If its potential is confirmed in the near future, contrast harmonic imaging will become a standard practice in EUS.     

Utility of endoscopic ultrasound in the diagnosis of aberrant right subclavian artery

BACKGROUND AND AIMS: Aberrant right subclavian artery (ARSA) is the most common congenital anomaly of the aortic arch occurring in 0.4-2.0% of the general population. Instead of arising from the brachiocephalic artery, the ARSA arises as the last branch from the aortic arch. The aim of this study was to determine the prevalence of ARSA in patients undergoing upper endoscopic ultrasound (EUS) and to describe the EUS characteristics of ARSA. METHODS: A retrospective review was conducted of 7513 upper EUS exams performed from 1 July 2000 to 1 February 2005. RESULTS: In total, 27 (0.36%, 95% CI 0.22-0.50%) of 7513 patients undergoing upper EUS were found to have an ARSA (10 male, 17 female; mean age 58 years, range 23-81 years). Of the 27 patients, 16 had only radial EUS, 10 had radial and linear EUS, and one had only linear EUS. In all 26 patients who underwent radial imaging, a well-defined, anechoic tubular structure was seen originating from the aortic arch and passing between the esophagus and spine. In all 11 patients undergoing linear imaging, the abnormal anatomy was detected and the vascular nature confirmed by Doppler. In one patient, both radial and linear imaging identified unsuspected aneurismal dilatation of the ARSA; a rare condition referred to as Kommerell's diverticulum (KD). None of the other 26 patients had symptoms to suggest an ARSA. Of the 14 patients who had computed tomography (CT) prior to EUS, only four were initially reported to have ARSA. However, later review of the CT scans verified an ARSA in all 14 patients. Of the two patients who underwent a barium swallow, only one had findings suggestive of ARSA. CONCLUSIONS: This report highlights the utility of both radial and linear EUS imaging in identifying previously unsuspected ARSA and associated anomalies. This report also suggests the need for careful review of the CT in patients suspected of having ARSA due to the frequent failure of radiologists to identify, or report, this anomaly when particular focus is not given.     

Endoscopic ultrasound criteria for vascular invasion in the staging of cancer of the head of the pancreas: a blind reevaluation of videotapes

BACKGROUND: It has been claimed in several prospective studies that endoscopic ultrasonography (EUS) is highly accurate in the locoregional staging of pancreatic cancer. However, the value of the EUS criteria for the diagnosis of vascular involvement is less well established. To totally exclude potential bias introduced by the availability of prior information, a completely blinded analysis of videotapes of patients with cancer of the pancreatic head was therefore conducted. METHODS: Videotape sequences of 75 patients with cancer of the head of the pancreas with surgical confirmation or unequivocally positive angiography demonstrating vascular invasion were reevaluated without any clinical data or information from other imaging studies. Involvement of the vascular system (portal vein with confluence, superior mesenteric vein, celiac axis) was assessed on EUS with special emphasis on EUS parameters of the tumor-vessel relationship. RESULTS: The overall sensitivity and specificity of EUS in the diagnosis of venous invasion were 43% and 91%, respectively, when using predetermined parameters (visualization of tumor in the lumen, complete obstruction, or collateral vessels). If the parameter "irregular tumor-vessel relationship" had been added to these criteria, the sensitivity would have risen to 62%, but the specificity would have fallen to 79%. The only vascular system that could be properly visualized by EUS was the portal vein/confluence area. The positive and negative predictive values for the single parameters chosen to diagnose portal venous involvement were as follows: 42% and 33% for irregular tumor-vessel relationship, 36% and 34% for visualization of tumor in the vascular lumen, 80% and 28% for complete vascular obstruction, and 88% and 18% for collateral vessels. CONCLUSIONS: In a completely blinded evaluation of the EUS diagnosis of vascular invasion by cancer of the head of the pancreas it was not possible to find suitable morphologic parameters with clinically useful sensitivity and specificity values (over 80%).     

EUS, PET, and CT scanning for evaluation of pancreatic adenocarcinoma

BACKGROUND: Preoperative diagnosis of pancreatic adenocarcinoma can be difficult. Computed tomography (CT) is the standard, noninvasive imaging method for evaluation of suspected pancreatic adenocarcinoma, but it has limited sensitivity for diagnosis, local staging, and metastases. Endoscopic ultrasound (EUS) and fluoro-deoxyglucose/positron emission tomography (FDG-PET) are imaging methods that may improve diagnostic accuracy. METHODS: Thirty-five patients with presumed resectable pancreatic adenocarcinoma were prospectively evaluated with helical CT, EUS, and FDG-PET. RESULTS: Sensitivity for the detection of pancreatic cancer was higher for EUS (93%) and FDG-PET (87%) than for CT (53%). EUS was more sensitive than CT for local vascular invasion of the portal and superior mesenteric veins. EUS diagnosis of vascular invasion was associated with poor outcome after surgery. EUS-guided, fine-needle aspiration allowed tissue diagnosis in 14 of 21 attempts (67%). FDG-PET diagnosed 7 of 9 cases of proven metastatic disease, 4 of which were missed by CT. Two of three metastatic liver lesions suspected by CT were indeterminate for metastases. FDG-PET confirmed metastases. CONCLUSIONS: EUS and PET improve diagnostic capability in pancreatic adenocarcinoma. EUS is useful in determining local vascular invasion and obtaining tissue diagnosis. FDG-PET is useful in identifying metastatic disease. Both techniques are more sensitive than helical CT for identification of the primary tumor. (Gastrointest Endosc 2000;52:367-71).     

Endoscopic ultrasound in clinical practice

Endoscopic ultrasonography (EUS) is an accurate technique for the diagnosis and staging of benign and malignant lesions in the gastrointestinal tract and the mediastinum. EUS overcomes the limitations of other imaging diagnostic methods and gives the possibility to obtain tissue for histologic diagnosis (EUS guided FNA). The most useful indications of EUS are differentiation of submucosal tumors, staging for neoplasia, examination of the pancreato-biliary system and therapeutics. EUS can distinguish extrinsic compressions from intramural lesions and defines their nature (solid, cystic or vascular) and origin. EUS is useful for local staging of esophageal, gastric, duodenal, and rectal cancer using the TNM (tumor, node, metastases) system, as well as for diagnosing and staging of pancreatic lesions. The addition of EUS-guided FNA has improved the ability to detect malignant lymph node invasion. EUS is also highly sensitive for the diagnosis of choledocholithiasis, avoiding unnecessary danger of diagnostic ERCP. New therapeutic indications of EUS include drainage of pancreatic pseudocysts and abscesses and celiac plexus block and neurolysis. EUS has become an indispensable diagnostic method in gastroenterological everyday practice and should be part of most endoscopy units.     

Preoperative staging and tumor resectability assessment of pancreatic cancer: prospective study comparing endoscopic ultrasonography, helical computed tomography, magnetic resonance imaging, and angiography

OBJECTIVES: The objective of this study was to evaluate prospectively the efficacy of different strategies based on endoscopic ultrasonography (EUS), helical computed tomography (CT), magnetic resonance imaging (MRI), and angiography (A) in the staging and tumor resectability assessment of pancreatic cancer. METHODS: All consecutive patients with pancreatic carcinoma judged fit for laparotomy were studied by EUS, CT, MRI, and A. Results of each of the imaging techniques regarding primary tumor, locoregional extension, lymph-node involvement, vascular invasion, distant metastases, tumor TNM stage, and tumor resectability were compared with the surgical findings. Univariate, logistic regression, decision, and cost minimization analyses were performed. RESULTS: Sixty-two patients with pancreatic cancer were included. Helical CT had the highest accuracy in assessing extent of primary tumor (73%), locoregional extension (74%), vascular invasion (83%), distant metastases (88%), tumor TNM stage (46%), and tumor resectability (83%), whereas EUS had the highest accuracy in assessing tumor size (r = 0.85) and lymph node involvement (65%). The decision analysis demonstrated that the best strategy to assess tumor resectability was based on CT or EUS as initial test, followed by the alternative technique in those potentially resectable cases. Cost minimization analysis favored the sequential strategy in which EUS was used as a confirmatory technique in those patients in whom helical CT suggested resectability of the tumor. CONCLUSIONS: Helical CT and EUS are the most useful individual imaging techniques in the staging of pancreatic cancer. In those cases with potentially resectable tumors a sequential approach consisting of helical CT as an initial test and EUS as a confirmatory technique seems to be the most reliable and cost minimization strategy.     

EUS imaging of the arteria lusoria: case series and review

BACKGROUND: The arteria lusoria is an aberrant right subclavian artery that passes dorsally between the esophagus and spine after branching off from the aortic arch. The role of endoscopic ultrasonography (EUS) in the diagnosis of the arteria lusoria has not been established. The possibility of demonstrating this vascular anomaly with EUS and estimating its prevalence was assessed. METHODS: From December 1991 to September 1998, EUS of the upper gastrointestinal tract was performed in 3334 consecutive patients for various reasons. After imaging of the target organ(s), the echoendoscope was slowly pulled back while imaging the mediastinum proximally to the superior aspect of the aortic arch. In every patient, the area of the aortic arch was carefully inspected and special attention was given to vessels crossing from left to right between the esophagus and spine. RESULTS: During the study period, an arteria lusoria was discovered in 12 of 3334 patients (0.36%: 95% CI [0.16%, 0.56%]). There were 6 men and 6 women; mean age was 64+/-14.7 years. In all 12 patients the arteria lusoria passed between the esophagus and spine. In none of the patients could symptoms be attributed to the presence of this anatomic variant. CONCLUSIONS: An arteria lusoria can be detected with upper gastrointestinal EUS and was found in 0.36% of patients. EUS can accurately demonstrate this vascular anomaly.     

CONTRAST‐ENHANCED ENDOSCOPIC ULTRASONOGRAPHY IN THE DIAGNOSIS OF PANCREATO‐BILIARY DISEASES

In diagnostic imaging, techniques represented by computed tomography (CT) and magnetic resonance imaging (MRI), diagnosis by evaluation of plain images in combination with contrast‐enhanced images is considered important. Recently, the ultrasound contrast media that can be administered from peripheral veins have been developed, and their utility is reported not only for the circulatory organ area but also the digestive organ area, mainly for liver diseases. As for the pancreato‐biliary diseases, there often are the cases that visualization of the diseases itself is not easy by transabdominal ultrasonography, so, the evaluation of contrast‐enhanced ultrasonography remains difficult. In contrast, endoscopic ultrasonography (EUS) is thought to be one of the most valuable modality for those diseases. The mainstream of an operation method of EUS was mechanical radial type, but in late years, endoscopic ultrasonography of an electronic linear method and an electronic radial method have been developed. Because an electronic scan method was adopted, we get possible to apply technology of color Doppler flow imaging and power Doppler flow imaging and harmonic imaging methods to EUS. We would like to outline the usefulness of contrast‐enhanced color/power Doppler EUS and contrast‐enhanced harmonic EUS, moreover, tissue harmonic imaging and three dimensional imaging, on the basis of our experiences.     

The expanding role of endoscopic ultrasound in pancreatic disease

Since endoscopic ultrasound (EUS) was first developed in the 1980s, this technology has emerged as the principal modality for imaging the pancreas. When compared with other imaging techniques, EUS can more accurately image solid lesions of the pancreas and determine vascular involvement that might preclude surgery. Furthermore, EUS-guided fine needle aspiration allows safe and accurate sampling and histological diagnosis of these lesions. EUS also plays a large role in the evaluation of cystic lesions of the pancreas. EUS cyst morphology, as well as fluid analysis obtained by fine needle aspiration, can often be used to diagnose the etiology of these lesions, helping the clinician to more accurately assess the presence or potential for malignancy. EUS can also predict the probability of the presence of chronic pancreatitis, primarily on the basis of histological correlates. The focus of this review is to discuss the role of EUS in these and other commonly encountered pancreatic diseases.     

Pancreatico-biliary endoscopic ultrasound: A systematic review of the levels of evidence, performance and outcomes

Our aim was to record pancreaticobiliary endoscopic ultrasound(EUS) literature of the past 3 decades and evaluate its role based on a critical appraisal of published studies according to levels of evidence(LE).Original research articles(randomized controlled trials,prospective and retrospective studies),meta-analyses,reviews and surveys pertinent to gastrointestinal EUS were included.All articles published until September 2011 were retrieved from PubMed and classified according to specific disease entities,anatomical subdivisions and therapeutic applications of EUS.The North of England evidencebased guidelines were used to determine LE.A total of 1089 pertinent articles were reviewed.Published research focused primarily on solid pancreatic neoplasms,followed by disorders of the extrahepatic biliary tree,pancreatic cystic lesions,therapeutic-interventional EUS,chronic and acute pancreatitis.A uniform observation in all six categories of articles was the predominance of LE Ⅲ studies followed by LE Ⅳ,Ⅱb,Ⅱa,Ⅰb and Ⅰ a,in descending order.EUS remains the most accurate method for detecting small( 3 cm) pancreatic tumors,ampullary neoplasms and small( 4 mm) bile duct stones,and the best test to define vascular invasion in pancreatic and peri-ampullary neoplasms.Detailed EUS imaging,along with biochemical and molecular cyst fluid analysis,improve the differentiation of pancreatic cysts and help predict their malignant potential.Early diagnosis of chronic pancreatitis appears feasible and reliable.Novel imaging techniques(contrast-enhanced EUS,elastography) seem promising for the evaluation of pancreatic cancer and autoimmune pancreatitis.Therapeutic applications currently involve pancreaticobiliary drainage and targeted fine needle injection-guided antitumor therapy.Despite the ongoing development of extra-corporeal imaging modalities,such as computed tomography,magnetic resonance imaging,and positron emission tomography,EUS still holds a leading role in the investigation of the pancreaticobiliary area.The major challenge of EUS evolution is its expanding therapeutic potential towards an effective and minimally invasive management of complex pancreaticobiliary disorders.     

Role of endoscopic ultrasound in the diagnosis of patients with solid pancreatic masses

Endoscopic ultrasound (EUS) is the most sensitive imaging procedure for the detection of small solid pancreatic masses and is accurate in determining vascular invasion of the portal venous system. Even compared to the new CT techniques, EUS provides excellent results in preoperative staging of solid pancreatic tumors. Compared to helical CT techniques, EUS is less accurate in detecting tumor involvement of the superior mesenteric artery. EUS staging and EUS-guided FNA can be performed in a single-step procedure, to establish the diagnosis of cancer. There is no known negative impact of tumor cell seeding due to EUS-guided fine needle aspiration (FNA). Without FNA, EUS and additional methods are not able to reliably distinguish between inflammatory and malignant masses.     

EUS diagnosis of vascular invasion in pancreatic cancer: surgical and histologic correlates

BACKGROUND: Endoscopic ultrasound (EUS) has been compared to intraoperative surgical palpation for diagnosis of vascular invasion by pancreatic cancer. This study compares EUS with vascular resection and histologic evidence of vascular invasion in resected pancreatic masses. METHODS: All patients with solid pancreatic masses who underwent both preoperative EUS and surgery at 1 hospital over a 7 year period were identified. The relationship of pancreatic masses to adjacent vessels was prospectively assessed by EUS. EUS findings were compared to surgical and pathology gold standards. "Vascular adherence" was defined as tumor adherence requiring vascular resection during surgery, and "vascular invasion" as histologic invasion of vessel wall by tumor. RESULTS: 30 of 68 patients were resectable. Among these 30, vascular adherence was present in 8, including 18% of patients with an intact echoplane between tumor and adjacent vessels at EUS, 29% of those with loss of echoplane alone, and 50% of those with additional EUS features of vascular involvement. Vascular invasion was present in 4, including 12% of patients with an intact echoplane, 0% of those with loss of echoplane alone, and 33% of those with additional EUS features. Sensitivity, specificity, PPV, and NPV of EUS were 63%, 64%, 43% and 80% for vascular adherence and 50% 58%, 28% and 82% for vascular invasion. NPV rose to 90% for vascular adherence if only the portal confluence vessels were considered. CONCLUSIONS: EUS has poor sensitivity, specificity, and positive predictive value for diagnosis of venous involvement by pancreatic cancer.     

Detection of occult liver metastases during EUS for staging of malignancies

BACKGROUND: EUS is commonly used in the staging of GI, thoracic, and other malignancies. Studies suggest EUS can detect occult liver metastases, but the frequency with which this occurs is unknown. METHODS: Records were reviewed for all patients seen during a 3-year period who underwent EUS of the upper-GI tract for staging of known or suspected malignancy. Patients were included if there was histopathologic evidence of malignancy, they had undergone noninvasive liver imaging within 6 weeks of EUS, and liver surveillance was specifically mentioned in the report of the EUS procedure. RESULTS: A total of 222 patients were included. Liver lesions were seen in 27 patients, 17 of whom had an abnormal noninvasive liver imaging test. EUS-guided FNA of the liver was performed in 21 patients and was diagnostic of malignancy in 15 (6.8%), 5 of whom (2.3%) had normal noninvasive imaging. In 6 patients, the EUS-guided FNA result was benign. EUS missed liver lesions in 4 patients known to have abnormalities by other imaging modalities. CONCLUSIONS: EUS can detect occult liver metastases in patients in whom noninvasive hepatic imaging studies are normal, although the frequency at which such lesions are detected is low. Liver surveillance during EUS is worthwhile for patients in whom there is another indication for the procedure; but, at present, EUS should not replace traditional imaging modalities.     

The accuracy of EUS and helical CT in the assessment of vascular invasion by peripapillary malignancy

BACKGROUND: The relative accuracy of helical CT and EUS for defining the local resectability of peripapillary malignancies is undefined. METHODS: Fifty-one patients with a peripapillary malignancy and no metastatic disease were prospectively evaluated with helical CT and EUS. Imaging results were compared with surgical staging, and a tumor was defined as resectable when there was no macroscopic or microscopic residual tumor. RESULTS: Nine patients had surgically confirmed locally unresectable disease, which was accurately predicted by EUS in 6 patients (sensitivity 67%) and by helical CT in 3 patients (sensitivity 33%; p = 0.35). When only patients with complete EUS examinations were included, the sensitivities of EUS and helical CT for vascular invasion were 100% and 33% (p = 0.06), respectively. When all patients not undergoing surgery because of imaging evidence of locally unresectable disease were included, the sensitivities were 100% and 62.5% (p = 0.02), respectively. One of 15 patients with a tumor amenable to surgical resection was labeled as unresectable by EUS but subsequently had a local recurrence of the tumor. The specificities of EUS (93%) and helical CT (100%) were similar. CONCLUSION: EUS is more sensitive than helical CT for detecting vascular invasion by peripapillary malignancies and should be added to staging protocols, particularly when findings on helical CT are equivocal.     

Recent advances and novel methods in pancreatic imaging

Traditional imaging studies for evaluating pancreatic disease including abdominal ultrasound (US) and computerized tomography (CT) are widely utilized due to their availability, non-invasiveness, and familiarity to practitioners. The addition of endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) has contributed significantly to the clinician's the ability to safely sample tissue, stage malignancy, evaluate the pancreatic ductal anatomy, and look for subtle parenchymal changes in the setting of chronic pancreatitis. The role of endoscopic retrograde cholangiopancreatography (ERCP) has diminished with the use of these less invasive modalities. Limitations in these conventional techniques include a lack of sensitivity and specificity in diagnosing early chronic pancreatitis, difficulties in differentiating malignancy from chronic or focal pancreatitis, and accuracy of staging pancreatic malignancy, particularly with regard to vascular involvement. Several recent advances in traditional imaging techniques have been described, which may improve our ability to accurately diagnose and stage pancreatic disease. Advances have been made in the standard modalities for imaging the pancreas such as multidetector CT, micro-bubble contrast enhanced ultrasound, and secretin stimulated MRCP. Other novel methods of pancreatic imaging have recently been described including EUS elastography, optical coherence tomography, diffusion weighted MRI, and MR spectroscopy. This article will review the recent advances in both traditional pancreatic imaging modalities as well as some of the emerging technologies for imaging evaluating diseases of the pancreas. As experience and clinical evidence accumulate, the role of these imaging techniques will continue to evolve.     

Endoscopic ultrasound

Indications and the clinical utility of endosonography have evolved as new technology, such as linear array echoendoscopes and EUS-guided fine needle aspiration, has emerged. The most noteworthy of the EUS applications are for cancer staging; including rectal, pancreatic, lung, and esophageal malignancies. There is little doubt that EUS is a powerful tool for cancer imaging, but its clinical impact in patient care and management has yet to be validated in prospective outcome studies. Other imaging modalities such as positron emission tomography (PET), dual-phased helical CT, and MR imaging technology will undoubtedly provide increasingly accurate diagnostic and staging information for gastrointestinal diseases. EUS imaging alone may assume a less significant role in relation to these noninvasive modalities in the future. EUS-guided FNA, as well as therapeutic EUS applications, will likely continue to expand in scope and play an important role in clinical medicine for many years to come.     

Endoscopic ultrasound-guided vascular interventions: An expanding paradigm

Endoscopic ultrasound(EUS) has expanded its arena from a mere diagnostic modality to an essential therapeutic tool in managing gastrointestinal(GI) diseases. The proximity of the GI tract to the vascular structures in the mediastinum and the abdomen has facilitated the growth of EUS in the field of vascular interventions. EUS provides important clinical and anatomical information related to the vessels’ size, appearance and location. Its excellent spatial resolution, use of colour doppler with o...