(BQ) Part 2 book The practice of ultrasound - A step by step guide to abdominal scanning has contents: Stomach, duodenum, and diaphragm, adrenal glands, the systematic ultrasound examination, bladder, prostate, and uterus,... and other contents.
7 Pancreas Organ Boundaries Locate and identify the pancreas Demonstrate the entire pancreas The pancreas is located in the retroperitoneum, bounded on each side by the duodenum and the spleen It lies transversely in the epigastrium, its axis directed at a slight angle from lower right to upper left Locating the pancreas Barriers to scanning The pancreas is often difficult to locate because of its posterior position The main barrier to scanning the pancreas is gas in the stomach and bowel (Fig 7.1) Optimizing the scanning conditions fig 7.1 The pancreas is obscured by the colon (Co), antrum (An), and costal arch (Ri) The pancreas, like the gallbladder, is best examined in the fasted patient In some cases, visualization can be significantly improved by giving the patient an antigas medication You can also apply local transducer pressure to push the gas aside Of course, this should be done only after the other organs have been examined Vision can be substantially improved by filling the stomach with water (500 ml, taken through a straw) (Fig 7.2) Fig 7.2 Locating the pancreas a Using the liver (L) as an acoustic window for locating the pancreas (P) An = antrum, Co = colon b Scanning through the fluid-filled antrum (An) Co = colon Organ identification More than with other upper abdominal organs, identification of the pancreas relies on the use of landmarks Your principal landmarks are the aorta and the splenic vein (Figs 7.3-7.5) Position the transducer for a high upper abdominal transverse scan, and angle the scan slightly upward into the liver Identify the aorta and vena cava Now move the scan plane caudally in small increments In some cases you will have to repeat this pass several times and use both sliding and angling movements of the probe to scan around gas in the stomach and bowel As you scan down the aorta, look for the landmarks shown in (Figs 7.3 and 7.4) Fig 7.3 Aorta (A) and celiac trunk (Tr) When you see this pattern in the transverse scan, you will find the pancreas at a slightly more caudal level 136 Fig 7.4 Aorta (A) plus a transverse section of the superior mesenteric artery (Ams) and a longitudinal section of the splenic vein (VI) When you see this pattern, you will almost always have the pancreas on the monitor It appears as a gently curved structure passing anterior to the splenic vein The ability to define the pancreas and delineate it from its surroundings will vary greatly from case to case b Demonstrate the aorta (A) c Locate the celiac trunk (->) d Identify the splenic vein ( pancreas anterior to it ( ) and the ) Difficulties in identifying the pancreas The series of images shown above were obtained under ideal scanning conditions In most examinations, however, the conditions will be less than ideal and often the pancreas cannot be completely visualized (Figs 7.6-7.8) Fig 7.6 Poor visualization of the pancreas ( ) due to obesity and overlying gas Fig 7.7 Obesity and pancreatic lipomaFig 7.8 The pancreas is completely tosis The superior mesenteric artery ( ) obscured by gas and splenic vein (