After you have checked in for your outpatient procedure, you will be given medication to help you relax for the EUS. During the procedure, the doctor will pass a thin, flexible tube (endoscope) through your mouth and your digestive tract. The tube contains a transducer that produces sound wave that creates an image of surrounding tissue. During the procedure a fine needle aspiration (FNA) may be done on lymph nodes, tumors or other abnormalities that are noted either during the exam or from previous radiology studies, such as a CT scan or MRI. FNA will extract fluid and tissue for analysis, then this sample is sent to pathology to evaluate. FNA will use a second curved device that is placed through a channel in the endoscope. The endoscope is then gradually withdrawn.