Abdominal CT scan
Abdominal CT scan Definition An abdominal CT scan involves X-ray images of the abdomen from many angles. The X-ray beams are detected by the scanner and analyzed by a computer. The computer reconstructs the data into a picture of the body area being scanned. These images can be viewed on a monitor or reproduced as photographs. Why the Test is Performed An abdominal CT is a noninvasive way for a health care provider to evaluate a patient's internal organs and tissues. There are many reasons for this -*test*-('") to be ordered. Some common uses are for the evaluation of tumors, infections, kidney stones, or appendicitis. How the Test is Performed The CT scanner is a free-standing machine with a large hole in the center. The patient lies on a narrow table that slides into the hole. In most cases the patient will be on his or her back with arms raised above his head. Patients who have difficulty with enclosed spaces such as those found with some MRI scanners do not usually have a problem with this type of -*test*-('"). A dye may be injected into a peripheral vein to better evaluate certain diseases and organs. The radiologist will decide if this is necessary. Tell the technician or radiologist if you have any allergies or have had difficulty with prior CT scans. It is very important that the patient remains still throughout the exam and holds his or her breath when asked. This will allow for better images. The actual scan time is usually about two minutes, although the entire procedure usually takes much longer. How to Prepare for the Test Tell the health care provider if you have any allergies or have had difficulty with prior CT scans. You may be advised to fast for 4 to 6 hours if contrast dye or sedation is to be used. You will be given a hospital gown to wear during the procedure. You may be asked to sign a consent form. How the Test Will Feel The X-rays are painless. The primary discomfort may be from the need to lie still on the table. If a dye is needed to increase the contrast between different tissues or organs, it is administered by injection into a vein. The injection may sting and the site may be tender to the touch for several minutes. Dye injections may cause a warm sensation, a metallic taste and, in a few cases, hives. Very rarely more severe contrast reactions can occur. Risks CT scans and other X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. CT scans provide low levels of radiation. During pregnancy, an abdominal CT scan is usually not recommended, because there is some evidence of risk to the fetus. The most common dye used is iodine based. A person who is allergic to iodine may experience nausea, sneezing, vomiting, itching, or hives. Rarely, the dye may cause anaphylaxis (a life-threatening allergic response). Considerations A CT scan provides a better picture of internal organs than conventional X-rays. The benefits of an abdominal CT scan usually far outweigh the risks of radiation exposure. What Abnormal Results Mean The CT scan may show the following: * Abdominal aortic aneurysm * Abscesses * Acute bilateral obstructive uropathy * Acute cholecystitis * Acute unilateral obstructive uropathy * Addison's disease * Amebic liver abscess * Appendicitis * Bilateral hydronephrosis * Bowel wall thickening * Carcinoma of the renal pelvis or ureter * Cholangiocarcinoma * Choledocholithiasis * Cholelithiasis * Chronic bilateral obstructive uropathy * Chronic cholecystitis * Chronic pancreatitis * Chronic unilateral obstructive uropathy * Complicated UTI (pyelonephritis) * Cystinuria * Cysts * Echinococcus * Enlarged lymph nodes * Enlarged organs * Gastroin-*test*-('")inal or bowel obstruction * Glucagonoma * Hairy cell leukemia * Hepatocellular carcinoma * Histoplasmosis; disseminated * Hodgkin's lymphoma * Islet of Langerhans' tumor * Multiple endocrine neoplasia (MEN) II * Nephrocalcinosis * Nephrolithiasis * Non-Hodgkin's lymphoma * Ovarian cancer * Pancreatic abscess * Pancreatic carcinoma * Pancreatic pseudocyst * Pancreatitis * Pheochromocytoma * Primary hyperaldosteronism * Pyelonephritis; acute * Pyogenic liver abscess * Renal cell carcinoma * Retroperitoneal fibrosis * Sclerosing cholangitis * Spontaneous retroperitoneal hemorrhage * Stones (bladder, kidney, liver, gall bladder) * Testicular cancer * Tumors * Unilateral hydronephrosis * Ureterocele * Wilms' tumor * Wilson's disease * Zollinger-Ellison syndrome Additional conditions under which the -*test*-('") may be performed include the following: * Acute renal failure * Alcoholic liver disease (hepatitis/cirrhosis) * Atheroembolic renal disease * Chronic glomerulonephritis * Chronic renal failure * Cushing's syndrome * Cushing's syndrome caused by adrenal tumor * Injury of the kidney and ureter * Medullary cystic disease * Multiple endocrine neoplasia (MEN) I * Polycystic kidney disease * Reflux nephropathy * Renal artery stenosis * Renal vein thrombosis * Skin lesion of histoplasmosis Review Date: 1/24/2005 Reviewed By: Jeffrey J. Brown, M.D., F.A.C.R., Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO. Review Provided by VeriMed Healthcare Network. A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2006A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited. adam.com
Abdominal CT scan Definition An abdominal CT scan involves X-ray images of the abdomen from many angles. The X-ray beams are detected by the scanner and analyzed by a computer. The computer reconstructs the data into a picture of the body area being scanned. These images can be viewed on a monitor or reproduced as photographs. Why the Test is Performed An abdominal CT is a noninvasive way for a health care provider to evaluate a patient's internal organs and tissues. There are many reasons for this -*test*-('") to be ordered. Some common uses are for the evaluation of tumors, infections, kidney stones, or appendicitis. How the Test is Performed The CT scanner is a free-standing machine with a large hole in the center. The patient lies on a narrow table that slides into the hole. In most cases the patient will be on his or her back with arms raised above his head. Patients who have difficulty with enclosed spaces such as those found with some MRI scanners do not usually have a problem with this type of -*test*-('"). A dye may be injected into a peripheral vein to better evaluate certain diseases and organs. The radiologist will decide if this is necessary. Tell the technician or radiologist if you have any allergies or have had difficulty with prior CT scans. It is very important that the patient remains still throughout the exam and holds his or her breath when asked. This will allow for better images. The actual scan time is usually about two minutes, although the entire procedure usually takes much longer. How to Prepare for the Test Tell the health care provider if you have any allergies or have had difficulty with prior CT scans. You may be advised to fast for 4 to 6 hours if contrast dye or sedation is to be used. You will be given a hospital gown to wear during the procedure. You may be asked to sign a consent form. How the Test Will Feel The X-rays are painless. The primary discomfort may be from the need to lie still on the table. If a dye is needed to increase the contrast between different tissues or organs, it is administered by injection into a vein. The injection may sting and the site may be tender to the touch for several minutes. Dye injections may cause a warm sensation, a metallic taste and, in a few cases, hives. Very rarely more severe contrast reactions can occur. Risks CT scans and other X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. CT scans provide low levels of radiation. During pregnancy, an abdominal CT scan is usually not recommended, because there is some evidence of risk to the fetus. The most common dye used is iodine based. A person who is allergic to iodine may experience nausea, sneezing, vomiting, itching, or hives. Rarely, the dye may cause anaphylaxis (a life-threatening allergic response). Considerations A CT scan provides a better picture of internal organs than conventional X-rays. The benefits of an abdominal CT scan usually far outweigh the risks of radiation exposure. What Abnormal Results Mean The CT scan may show the following: * Abdominal aortic aneurysm * Abscesses * Acute bilateral obstructive uropathy * Acute cholecystitis * Acute unilateral obstructive uropathy * Addison's disease * Amebic liver abscess * Appendicitis * Bilateral hydronephrosis * Bowel wall thickening * Carcinoma of the renal pelvis or ureter * Cholangiocarcinoma * Choledocholithiasis * Cholelithiasis * Chronic bilateral obstructive uropathy * Chronic cholecystitis * Chronic pancreatitis * Chronic unilateral obstructive uropathy * Complicated UTI (pyelonephritis) * Cystinuria * Cysts * Echinococcus * Enlarged lymph nodes * Enlarged organs * Gastroin-*test*-('")inal or bowel obstruction * Glucagonoma * Hairy cell leukemia * Hepatocellular carcinoma * Histoplasmosis; disseminated * Hodgkin's lymphoma * Islet of Langerhans' tumor * Multiple endocrine neoplasia (MEN) II * Nephrocalcinosis * Nephrolithiasis * Non-Hodgkin's lymphoma * Ovarian cancer * Pancreatic abscess * Pancreatic carcinoma * Pancreatic pseudocyst * Pancreatitis * Pheochromocytoma * Primary hyperaldosteronism * Pyelonephritis; acute * Pyogenic liver abscess * Renal cell carcinoma * Retroperitoneal fibrosis * Sclerosing cholangitis * Spontaneous retroperitoneal hemorrhage * Stones (bladder, kidney, liver, gall bladder) * Testicular cancer * Tumors * Unilateral hydronephrosis * Ureterocele * Wilms' tumor * Wilson's disease * Zollinger-Ellison syndrome Additional conditions under which the -*test*-('") may be performed include the following: * Acute renal failure * Alcoholic liver disease (hepatitis/cirrhosis) * Atheroembolic renal disease * Chronic glomerulonephritis * Chronic renal failure * Cushing's syndrome * Cushing's syndrome caused by adrenal tumor * Injury of the kidney and ureter * Medullary cystic disease * Multiple endocrine neoplasia (MEN) I * Polycystic kidney disease * Reflux nephropathy * Renal artery stenosis * Renal vein thrombosis * Skin lesion of histoplasmosis Review Date: 1/24/2005 Reviewed By: Jeffrey J. Brown, M.D., F.A.C.R., Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO. Review Provided by VeriMed Healthcare Network. A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2006A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited. adam.com