Читать книгу Pancreatic Tumors - Группа авторов - Страница 12

Before the advent of endoscopic ultrasonography (EUS), percutaneous ultrasonography (US)-guided fine-needle aspiration (FNA) biopsies and computed tomography (CT)-guided FNA biopsies were utilized for obtaining tissue for cytological examination. Beginning in the 1970s, US was the first imaging modality used, with the use of CT reported a few years later [11, 12]. EUS was developed in the 1980s to overcome limitations of transabdominal US imaging of the pancreas caused by intervening gas, bone, and fat, and is currently the most common source of obtaining material from pancreatic lesions. EUS provides excellent visualization of the pancreatic head and uncinate process from the duodenum as well as the body and tail of the pancreas from the stomach. With the advent of curvilinear echo endoscopes, both transgastric and transduodenal EUS-guided FNA (EUS-FNA) biopsies of the pancreas have become a possibility. EUS is superior to percutaneous US and CT scan, especially when the pancreatic tumor is <2–3 cm [13, 14]. In hospitals where CT-guided biopsies and/or endoscopic retrograde cholangiopancreatography (ERCP) brushings are still the standard methods for obtaining tissue for diagnosis of pancreatic lesions, false negative rates of >30% have been reported [15]. Advantages of EUS-FNA over other modalities include the close proximity of the target lesion to the endoscope, sampling under direct ultrasound guidance, and avoidance of overlying bowel [16].