EUS Shear Wave for Solid Pancreatic Lesions.

The diagnosis of pancreas diseases is based on a combination of clinical signs, symptoms, and laboratory tests, but mainly on imaging techniques such as computed tomography (CT) and magnetic resonance (MR). However, CT/MR have variable sensitivity and specificity, with certain disadvantages. Endoscopic ultrasound with elastography is an important resource with higher diagnostic accuracy in assessing solid pancreas lesions. Shear wave velocities of healthy parenchyma, acute, chronic and autoimmune pancreatitis, neoplastic lesions of the pancreas must be evaluated and compared.

The pancreas is a retroperitoneal organ that can cause inflammatory and neoplastic diseases, significantly impacting the quality of life to survival. Acute pancreatitis is one of the most frequent gastrointestinal causes for hospital admission in industrialized countries. Chronic pancreatitis, although lower in incidence, significantly reduces patients' quality of life. Pancreas cancer is one of the neoplastic diseases with high mortality worldwide. Those diseases have been associated with significant morbidity, mortality, and hospitalization costs

The diagnosis of pancreas diseases is based on a combination of clinical signs, symptoms, and laboratory tests, but mainly on imaging techniques such as computed tomography (CT) and magnetic resonance (MR). Imaging provides a significant contribution to the diagnosis of pancreatic diseases and severity estimation or staging for inflammatory and neoplastic lesions, respectively. However, CT/MR have variable sensitivity and specificity, with certain disadvantages.

Endoscopic ultrasound with elastography is an important resource with higher diagnostic accuracy in assessing solid pancreas lesions. Shear wave elastography is a novel technique that can measure tissue elasticity by generating shear waves inside the organ using the acoustic radiation force impulse.

EUS Shear wave velocities of healthy parenchyma and solid pancreas lesions as acute, chronic, autoimmune pancreatitis and neoplasia are under described and must be evaluated and contrasted. Therefore, the present study pursues to estimate the diagnostic accuracy of EUS Shear wave for neoplasia assessment among solid pancreas lesions.

Eligibility Criteria:
Inclusion Criteria:

* Neoplasia group: high suspicion of pancreas neoplasia based on computed tomography and/or nuclear magnetic resonance.
* Inflammatory group: high suspicion of acute or chronic pancreatitis based on computed tomography and/or nuclear magnetic resonance.
* Control group: patients without a history of any type of solid or hematologic malignancy, hepato-pancreato-biliary disease (including fatty liver and pancreas disease), tobacco/alcohol habits, or morbid obesity with bariatric surgery criteria; who require EUS evaluation (e.g., suspicious of a subepithelial lesion in the context of chronic dyspepsia).

Exclusion Criteria:

* Uncontrolled coagulopathy, kidney/liver failure, or any comorbidity with important impact on cardiac risk assessment (NHYA III/IV);
* Impossibility of EUS-guided biopsy (only for neoplasia or inflammatory group);
* Pregnancy or nursing;
* Refuse to participate in the study and/or to sign corresponding informed consent.