WHAT IS PANCREAS ULTRASONOGRAPHY (PANCREAS ECHOGRAM, PANCREAS ULTRASOUND) TEST?
Evaluation of pancreatic structure by the creation of an oscilloscopic picture from the echoes of high-frequency sound waves passing over the epigastric area (acoustic imaging). A variation of the technique involves moving the probe intraductally via endoscopic ultrasonography (see Endoscopic ultrasonography—Diagnostic). The time required for the ultrasonic beam to be reflected back to the transducer from differing densities of tissue is converted by a computer to an electrical impulse displayed on an oscilloscopic screen to create a three-dimensional picture of the pancreas. An advantage of this test is that it can help diagnose acute pancreatitis retrospectively. In acute pancreatitis, the pancreas appears larger than normal and is less echogenic than the liver. Oedema may cause compression of the inferior vena cava, and the pancreatic duct may appear enlarged. In chronic pancreatitis, calculi, shadows, strictures, or stenoses may be viewed in the pancreatic duct as well as calcified areas in the body of the pancreas. An abscess may appear as an irregular-shaped, highly echogenic structure with thick walls. Adenocarcinoma may cause the gland to appear enlarged, with an irregular border and absence of normal parenchymal echo pattern. True cysts may be differentiated from pseudocysts by their spherical, sonolucent appearance. Pseudocysts are nonspherical and may contain scattered echoes caused by debris contained within them.