Ultrasonography of the pancreas. 6. Endoscopic imaging

Abstract

EUS is a high-resolution technique for pancreatic imaging. EUS has applictions in detecting and staging pancreatic tumors, EUS guided FNA of the pancreas for tissue diagnosis, and evaluation of chronic pancreatitis as well as EUS guided therapy such as celiac plexus block. This is a review of EUS imaging (EUS) of the pancreas covering technical aspects, clinical indications, advantages, and pitfalls as well as emerging trends in the field.

Italian consensus guidelines for chronic pancreatitis

“…Thanks to the high spatial and contrast resolution of this tomographic technique, CT is able to detect ductal calcium deposits [128][129][130]. Furthermore it localizes pancreatic stones inside the lumen of the main pancreatic duct and/or side branches, within the pancreatic head/body/tail, or diffuse.…”

“…However, transabdominal US is limited by patient body habitus and meteorismus. Furthermore this technique shows a lower spatial and contrast resolution, therefore a negative ultrasound does not exclude the presence of stones [129,130]. Gadolinium-chelates enhanced MR imaging combined with MRCP is a less suitable diagnostic imaging modality for the diagnosis of pancreatic stones, since it does not depict the stones directly but only indirectly as filling defects within the pancreatic duct system.…”

Endoscopic ultrasound and pancreatic applications: what the radiologist needs to know

“…1). In addition, the image quality can be further improved by the removal of air, and instillation of water, into the gut lumen [2,3].…”

“…1). In particular, the linear array endoscope is thought to be technically more difficult for the endoscopist to maneuver, but is of great value during EUSguided FNA, allowing the visualization of the needle along its entire length [2,3]. High frequency probes can also be used which are inserted through the biopsy channel of a regular endoscope.…”

“…Nevertheless, EUS has been shown to be clearly superior to CT in its ability to detect pancreatic cancer, with sensitivities ranging from 96% to 98% [2,12,21,22]. However, given the ability of CT to detect the vast majority of pancreatic cancers in a far less invasive fashion, the primary diagnostic utility of EUS is based upon: (1) the use of EUS in ambiguous cases where a mass is suspected, but cannot be absolutely confirmed on CT, and (2) the ability to perform EUSguided FNA.…”