This technique has been introduced in the early 1980s (9), just to HKI 272 overcome difficulties in visualization of the pancreas on transabdominal US. It has been for many years a mere imaging modality, but the development of new electronic instruments with linear or sector scanner allowed

the visualization in the echografic field of a needle coming out from the operative channel of the echoendoscope so guiding the needle in the target lesion both within and outside the GI wall. So we witnessed in the early 1990s at the birth of interventional EUS, both Inhibitors,research,lifescience,medical diagnostic and therapeutic. For many years EUS has been advocated as the best available technique for imaging the pancreas and the extra-hepatic biliary tree. High resolution images of the main pancreatic duct and surrounding parenchyma can be achieved and structures as small as 2-3 Inhibitors,research,lifescience,medical mm can be distinguished thanks to the small distance between the transducer and

the gland, that allows to use higher frequency probes, from 7.5 to 20 MHz, with lower penetration depth but more elevated spatial resolution (10). EUS, compared with transabdominal Inhibitors,research,lifescience,medical US, CT and MRI, has a superior parenchymal resolution, that gives reason for the results of several studies establishing the higher sensitivity of EUS (98%) in the diagnosis of PC in comparison to all the other imaging modalities, i.e., US (75%), CT (80%), even with pancreatic protocols, angiography (89%) and so on (11,12). The results of EUS were even better in small tumors, less than 3 cm, where sensitivity of US and CT decreased to only 29% (11). However, the introduction of Inhibitors,research,lifescience,medical multidetector helical CT (MDHCT) has today revolutionized the field of pancreatic imaging and “has created a new dimension of temporal and spatial resolution” reaching a sensitivity of 97-100% and a non-resectability prediction Inhibitors,research,lifescience,medical near to 100% (13). Also MRI, developed in the early 1990s, has known great improvement in technology and softwares in the last ten years, with the addition

of magnetic resonance cholangiopancreatography (MRCP) and MR angiography. The reported sensitivity of MRI ranges from Rolziracetam 83% to 87% with a specificity from 81% to 100%. Given the increasing sensitivity of MDHCT and the high cost of MRI, the latter to date should not be considered the first choice in PC diagnosis and staging, even though MRI may be useful in the detection and characterization of non-contour-deforming pancreatic masses and it is more sensitive than CT in the detection and characterization of small liver metastases and peritoneal and omental metastases (10,14). In the last ten years EUS had to bear the weight of the rapidly evolving technology of radiological imaging modalities and finally also the advent and the evolution of nuclear imaging such as positron emission tomography (PET) (15) and the integrated approach PET/CT, aimed to overcome the major disadvantage of PET scan, that is the limited anatomical information (16).