You are not lying in a "tube." The examination takes place in a "ring" through which the patient can see during the examination. A "tube" is used in MRI. Unlike an MRI examination, a CT examination only takes a few minutes. The scanning unit of the computer tomograph, the gantry, is like a disc approximately 70 cm thick with an opening in the middle through which patients can quickly pass and see through. Even people with claustrophobia have no problems with this. If claustrophobia does occur, a sedative can be administered. This must be prescribed by your family doctor and, if necessary, provided. However, this will impair your ability to drive, so you should not come in your own car in this case. In this rare case, an accompanying person is required.

Contrast agents administered into the bloodstream accumulate in areas with strong blood flow. This makes these structures easier to assess than without contrast agents. These include most tumors, but also inflammatory processes. Conversely, in internal organs with strong blood flow, pathological processes sometimes stand out due to their lower blood flow compared to healthy tissue. In most cases, contrast agents can be used to distinguish between benign and malignant areas. In addition, contrast agents may be given to drink during examinations of the gastrointestinal tract. These agents stain the intestinal loops so that they can be better distinguished from other structures in the abdominal cavity.

Contrast agents administered into the bloodstream accumulate in areas with strong blood flow. This includes most tumors, but also inflammatory processes. In internal organs with strong blood flow, pathological processes sometimes stand out due to their lower blood flow compared to healthy tissue. In most cases, benign and malignant areas can be distinguished from each other using contrast agents. In addition, contrast agents are usually given to drink during examinations of the gastrointestinal tract. It colors the intestinal loops. The contrast agent in the bloodstream is excreted by the kidneys within a few minutes and is completely removed from the body after about 6 hours. Problems can arise if kidney function is impaired. The simplest sign of this is a change in the laboratory value, the creatinine value. This is often requested before the CT scan. The second contrast agent, which is drunk, is absorbed to a small extent, but most of it simply remains in the intestine and is excreted in this way. Contrast agents in other parts of the body are absorbed into the blood or lymph and then excreted via the kidneys. Bile-soluble contrast agents also enter the blood, but are excreted via the liver into the bile ducts and from there into the intestine.

No, most examinations of the spine, skeletal system, joints, teeth, and sinuses, as well as bone density measurements using CT (QCT), do not require contrast agents. However, contrast agents are usually necessary for examinations of the brain, soft tissues of the neck, chest, and abdomen in order to obtain optimal results.

CT scans cannot be performed during pregnancy due to radiation exposure. Alternative examination methods such as ultrasound or, in special cases, MRI can be helpful. Other contraindications only apply to the administration of contrast agents – in such cases, the examination may be performed without contrast agents: Contrast agents should not be administered in most forms of hyperthyroidism, in cases of severe contrast agent intolerance in the patient's medical history, in cases of severe cardiovascular disease, in cases of severe renal dysfunction, and in cases of the bone marrow disease "plasmacytoma."

Please bring a current doctor's letter and your latest blood test results with you. Caffeinated drinks or performance-enhancing substances should be avoided on the day of the examination (if possible, for 24 hours beforehand). Potency-enhancing medications (e.g., Viagra) must be discontinued at least 36 hours before the examination.

Low-dose CT uses a CT technique that requires a significantly reduced radiation dose. In return, the quality of the images is poorer and they appear blurrier. However, such compromises in quality can be accepted in many cases, as the examination is not used in patients with a specific suspicion of malignant neoplasms (cancer), but rather as a screening or early detection measure in patients with a certain probability of such a disease (e.g., to detect lung cancer in long-term smokers). Low-dose computed tomography may also be suitable for monitoring the progression of a known diagnosis. Compared to a standard CT scan of the lungs, the dose can be significantly reduced.