Daniela Dumitrescu

Power Doppler endoscopic ultrasonography for the differential diagnosis between pancreatic cancer and pseudotumoral chronic pancreatitis.

Objective. The accuracy of endoscopic ultrasonography (EUS) and EUS‐guided fine‐needle aspiration for the differential diagnosis of pancreatic masses is variable in the literature, being as low as 75% in some studies. The aim of the study was to assess the accuracy of power Doppler EUS for the differential diagnosis between pancreatic cancer and pseudotumoral chronic pancreatitis. Methods. We included 42 consecutive patients with pancreatic tumor masses (27 men and 15 women) examined by EUS between January 2002 and August 2004. Endoscopic ultrasonographic procedures included power Doppler EUS as well as EUS‐guided fine‐needle aspiration in all patients. Final diagnosis of pancreatic cancer was confirmed in 29 patients on the basis of a combination of information provided by imaging tests, follow‐up of at least 6 months, and laparotomy in 18 patients for diagnostic or palliative reasons. Results. Sensitivity and specificity of the absence of power Doppler signals inside the suggestive pancreatic mass were 93% and 77%, respectively, with accuracy of 88%. Moreover, the addition of the information provided by the presence of peripancreatic collaterals improved the sensitivity and specificity to 97% and 92%, with accuracy of 95%. Conclusions. Power Doppler EUS provides useful information for the differential diagnosis of pancreatic masses. The results were in concordance with previous studies that showed a hypovascular pattern of pancreatic carcinoma, as well as the formation of collaterals in advanced cases due to the invasion of the splenic or portal veins. Further studies of dynamic EUS with contrast agents are necessary to better characterize pancreatic masses.

Hybrid ultrasound imaging techniques (fusion imaging)

Visualization of tumor angiogenesis can facilitate non-invasive evaluation of tumor vascular characteristics to supplement the conventional diagnostic imaging goals of depicting tumor location, size, and morphology. Hybrid imaging techniques combine anatomic [ultrasound, computed tomography (CT), and/or magnetic resonance imaging (MRI)] and molecular (single photon emission CT and positron emission tomography) imaging modalities. One example is real-time virtual sonography, which combines ultrasound (grayscale, colour Doppler, or dynamic contrast harmonic imaging) with contrast-enhanced CT/MRI. The benefits of fusion imaging include an increased diagnostic confidence, direct comparison of the lesions using different imaging modalities, more precise monitoring of interventional procedures, and reduced radiation exposure.

EUS-assisted rendezvous stenting of the pancreatic duct for chronic calcifying pancreatitis with multiple pseudocysts.

Introduction: The best choice of endoscopic drainage of pancreatic pseudocysts complicating chronic pancreatitis is currently unknown, with EUS-guided transmural drainage competing with ERCP transpapillary techniques. However, recent studies currently recommend the use of both techniques in complex cases. Case Presentation: We present the case of a 60-year-old male patient with chronic calcifying pancreatitis, with severe ductal obstruction and multiple communicating pancreatic pseudocysts. The patient presented in the emergency department with weight loss, jaundice, steatorrhea and diabetes. Initial imaging evaluation (by transabdominal US, EUS and MRCP) depicted a dilated common bile duct, intrahepatic bile ducts and dilated main pancreatic duct (up to 1 cm) with multiple stones, as well as three pseudocysts at the level of the pancreatic head and one pseudocyst at the level of the pancreatic tail. ERCP with direct cannulation and transpapillary drainage of the bile duct or pancreatic duct was unsuccessful. Consequently, a EUS-assisted rendezvous stenting of the pancreatic duct was done, with the transpapillary placement of a 5-cm stent. Biliary cannulation was also possible with the placement of a double pigtail 9-cm stent in the common bile duct. Subsequent evolution was rapidly favorable with the disappearance of the pancreatic pseudocysts on the control CT after 24 h. Conclusion: Our case clearly showed the benefit of combined draining procedures even in cases of chronic pancreatitis with multiple pseudocysts where surgical drainage was previously deemed necessary.

Imaging tests for accurate diagnosis of acute biliary pancreatitis

Gallstones represent the most frequent aetiology of acute pancreatitis in many statistics all over the world, estimated between 40%-60%. Accurate diagnosis of acute biliary pancreatitis (ABP) is of outmost importance because clearance of lithiasis [gallbladder and common bile duct (CBD)] rules out recurrences. Confirmation of biliary lithiasis is done by imaging. The sensitivity of the ultrasonography (US) in the detection of gallstones is over 95% in uncomplicated cases, but in ABP, sensitivity for gallstone detection is lower, being less than 80% due to the ileus and bowel distension. Sensitivity of transabdominal ultrasonography (TUS) for choledocolithiasis varies between 50%-80%, but the specificity is high, reaching 95%. Diameter of the bile duct may be orientative for diagnosis. Endoscopic ultrasonography (EUS) seems to be a more effective tool to diagnose ABP rather than endoscopic retrograde cholangiopancreatography (ERCP), which should be performed only for therapeutic purposes. As the sensitivity and specificity of computerized tomography are lower as compared to state-of-the-art magnetic resonance cholangiopancreatography (MRCP) or EUS, especially for small stones and small diameter of CBD, the later techniques are nowadays preferred for the evaluation of ABP patients. ERCP has the highest accuracy for the diagnosis of choledocholithiasis and is used as a reference standard in many studies, especially after sphincterotomy and balloon extraction of CBD stones. Laparoscopic ultrasonography is a useful tool for the intraoperative diagnosis of choledocholithiasis. Routine exploration of the CBD in cases of patients scheduled for cholecystectomy after an attack of ABP was not proven useful. A significant rate of the so-called idiopathic pancreatitis is actually caused by microlithiasis and/or biliary sludge. In conclusion, the general algorithm for CBD stone detection starts with anamnesis, serum biochemistry and then TUS, followed by EUS or MRCP. In the end, bile duct microscopic analysis may be performed by bile harvested during ERCP in case of recurrent attacks of ABP and these should be followed by laparoscopic cholecystectomy.

Technique of qualitative and semiquantitative EUS elastography in pancreatic examination

Multiple pathological processes can induce alterations of tissue stiffness.[1] For example, malignant tumors are often stiffer than the surrounding tissue. Manual palpation provides very useful information about the elasticity of tissues. However, the organs located deep in the body cannot be evaluated by manual palpation. Nowadays, it is possible to perform a virtual palpation of the internal organs by applying elastography, which is an emerging set of imaging modalities used to reproduce tissue elasticity.[2] Endoscopic ultrasound (EUS) elastography, described for the first time in 2005, remains an appropriate method for the assessment of pancreaticobiliary diseases.[3,4,5,6,7,8]