Abdominal ultrasonography

Abstract

Abdominal ultrasonography (also called abdominal ultrasound imaging or abdominal sonography) is a form of medical ultrasonography(medical application of ultrasound technology) to visualise abdominal anatomical structures. It uses transmission and reflection of ultrasound waves to visualise internal organs through the abdominal wall (with the help of gel which helps transmission of the sound waves). For this reason, the procedure is also called a transabdominal ultrasound, in contrast with endoscopic ultrasound, the latter combining ultrasound with endoscopy through visualize internal structures from within hollow organs. Abdominal ultrasound examinations are performed by gastroenterologists or certain other specialists in internal medicine, radiologists or sonographerstrained for this procedure. Ultrasound testing helps in the diagnosis of a wide range of diseases and conditions, including stomach problems, gallbladder or pancreas problems, and abdominal pain. During an ultrasound test, high-frequency sound waves, inaudible to the human ear, are transmitted through body tissues using an instrument called a transducer, which transmits the information to a computer that displays the information on a monitor. Ultrasound is used to create images of soft tissue structures, such as the gallbladder, liver, kidneys, pancreas, bladder, and other organs and parts of the body. Ultrasound can also measure the flow of blood in the arteries to detect blockages. Ultrasound testing is safe and easy to perform. Abdominal ultrasound can be used to diagnose abnormalities in various internal organs, such as the kidneys, liver, gallbladder, pancreas, spleen andabdominal aorta. If Doppler imaging is added, the blood flow inside blood vessels can be evaluated as well (for example, to look for renal artery stenosis). Through the abdominal wall, organs inside the pelvis can be seen, such as the as urinary bladder or the ovaries and uterus in women. Because water is an excellent conductor for ultrasound waves, visualizing these structures often requires a well-filled urinary bladder (this means the patients has to drink plenty of water before the examination). Abdominal ultrasound is commonly used in the setting of abdominal pain or an acute abdomen (sudden and/or severe abdominal pain syndrome in which surgical intervention might be necessary), in which it can diagnose appendicitis or cholecystitis. In patients with deranged liver function tests, ultrasound may show increased liver size (hepatomegaly), increased reflectiveness (which might, for example, indicate cholestasis), gallbladder or bile duct diseases, or a tumor in the liver. The same is true for patients with an abnormal kidney functionor pancreatic enzymes (pancreatic amylase and pancreatic lipase), in which ultrasound can be used for additional anatomical information. Ultrasound can also be used if there is suspicion of enlargement of one or more organs, such as used in screening for abdominal aortic aneurysm, investigation for splenomegaly or urinary retention. Ultrasound imaging is useful for detecting stones, for example kidney stones or gallstones, because they create a clearly visible ultrasound shadow behind the stone. Ultrasonography can be used to guide procedures such as treatment for kidney stones with Extracorporeal shock wave lithotripsy, needle biopsies orparacentesis (needle drainage of free fluid inside the abdominal cavity). Ultrasound may be used to detect the following digestive problems: • Cysts or abnormal growths in the liver, spleen, or pancreas • Abnormal enlargement of the spleen • Cancer of the liver or fatty liver • Gallstones or sludge in the gallbladder Generally, no special preparation is needed for an ultrasound. Depending on the type of test, you may need to drink fluid before the ultrasound or you may be asked to fast for several hours before the procedure. During the Ultrasound: you will lie on a padded examination table; a specially trained technologist will perform the test; A small amount of water-soluble gel is applied to the skin over the area to be examined. The gel does not harm your skin and will be wiped off after the test; a wand-like device called a transducer is gently applied against the skin, you may be asked to hold your breath briefly several times; the ultrasound test takes several minutes to complete, a radiologist will interpret the test results. Studies have shown that ultrasound is not hazardous. There are no harmful side effects and there is virtually no discomfort during the test. In addition, ultrasound does not use radiation, as X-ray tests do.