Patient Education - Endocrine Encyclopedia
Endocrine Surgery Encyclopedia
 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.
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.
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.
Normal Values:
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
- Gastrointestinal 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
What the risks are:
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).
Special 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.
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.
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