Diagnosis of Pancreatic Diseases using Endoscopic Ultrasonography ( EUS ) -Emphasizing the significance of Elastography-

The transabdominal ultrasonography (US) is recognized as a useful tool for the diagnosis of pancreatic diseases, it is also true that its essential weakness of “not being able to see through air” becomes a considerable handicap when observing the pancreas, which is for the most part located behind the gastrointestinal organs. Endoscopic ultrasonography (EUS) was developed to minimize the effect of air or residue by enabling observation from inside the gastrointestinal tract. Because EUS enables observation from inside the intestinal tract, it has the advantages of attenuating the abovementioned artifacts while enabling observation by high frequency ultrasonography because the target disease can be observed from the proximal region. EUS is a form of endoscopy but it is essentially ultrasonography. Obviously, taking into consideration the huge developments that have recently been made in ultrasonography, it would be difficult for EUS to survive as a diagnostic method with only its present advantages. This situation has spurred the introduction of new EUS systems. The evolution of EUS in recent years is shown in Table 1. At first, only mechanical radial scanning type EUS was available but electronic scanning Convex/Linear type EUS is now applied clinically. Color Doppler, Power Doppler and FFT analysis are applicable with this method, and it has become possible to make diagnoses of diseases that require evaluation of blood flow. Other huge clinical benefits of EUS include EUS guided fine needle aspiration (EUS-FNA) of the target disease.