Abdominal Computer Tomography

Computed tomography of the abdomen (synonyms: CT abdomen; abdominal CT) refers to a radiological examination procedure in which the abdomen (abdominal cavity) with its organs is examined using computed tomography CT).

Indications (areas of application)

  • Tumors in the abdomen (abdominal region) such as gastric carcinoma, pancreatic carcinoma (cancer of the pancreas), liver carcinoma, renal tumors, adrenal tumors.
  • Gynecological tumors such as cervical carcinoma (cervical cancer), ovarian tumors (ovarian tumors) – to exclude metastases (daughter tumors) in the context of staging (tumor stage).
  • Lymphomas in the abdomen due to tumorous changes or systemic lymph node diseases such as Hodgkin’s disease.
  • Changes in blood vessels such as atherosclerosis (arteriosclerosis, hardening of the arteries), aneurysms, aortic dissection (tear of the aortic wall).
  • Acute abdomen – acute abdominal pain associated with defensive tension and can have many causes.
  • Inflammatory processes such as abscesses in the abdomen (abdominal area).
  • Suspected spontaneous or iatrogenic perforation (puncture or perforation) of a hollow organ (sensitivity/percentage of diseased patients in whom the disease is detected by using the test, i.e., a positive test result occurs from 90-95%)

The procedure

Computed tomography is one of the non-invasive, that is, not penetrating into the body, imaging X-ray diagnostic procedures. The body or the body part to be examined is imaged layer by layer with a rapidly rotating X-ray tube. A computer measures the attenuation of the X-rays as they pass through the body and uses this information to determine a detailed image of the part of the body being examined. The principle of CT (computed tomography) is to show the density differences of different tissues. For example, water has a different density than air or bone, which is expressed in different shades of gray. For even better differentiation of the tissue types, the patient can also be administered a contrast medium. This is contrast medium containing iodine. Healthy tissue absorbs contrast medium at a different rate than diseased tissue such as cancer. The examination takes only a few minutes with the most modern equipment, i.e. the scanning process even only a few seconds, so that the patient can hold his breath during the examination process and movement artifacts become impossible. The examination is performed while the patient is lying down. The latest devices use the multislice method, i.e. several slices are taken at the same time. Modern examination devices use a 64-slice method, i.e. 64 slices are taken at the same time. This method can be compared to a Rettig, which is cut in a spiral shape. In this case, however, only one slice is involved, and in the method described above, 64 slices are produced one inside the other as a spiral and processed by the computer. Modern devices also work with a so-called low-dose technique, i.e. only 50% of the radiation is required to produce these precise images with a slice thickness of up to 0.4 mm. New reconstruction algorithms (reconstruction calculation methods) make this precision possible.

Notes on radiation-induced cancer and mortality risk (risk of death) from abdominal CT: according to a model calculation for cancer risk averaged over all persons and all age groups, 1 in 2,000 persons exposed to a single radiation dose of 10 mSv die from cancer.

Computed tomography of the abdomen is now routinely used for many indications because it is a rapid and highly informative diagnostic procedure.