What Tests Should Be Done Before a CT Scan?

If a CT scan is planned without the use of a contrast agent, no laboratory tests are required. However, if contrast-enhanced CT is scheduled, it is important to check the blood creatinine level and glomerular filtration rate, especially in patients over 65 years of age or those with kidney disease. This is essential because iodine-containing contrast agents are eliminated through the kidneys, and their proper function must be confirmed.

Why Is Creatinine Tested Before a CT Scan?

Blood creatinine is an indicator of kidney function. Since contrast agents used in CT scans contain iodine, which is excreted by the kidneys, it is necessary to ensure that the kidneys can effectively remove the excess iodine from the body.

What Creatinine Level Is Acceptable for a CT Scan?

If the CT scan is performed without contrast, the creatinine level can be any value. If a contrast agent is to be administered, the creatinine level should be within the age-adjusted normal range, usually 102–127 µmol/L, depending on the measurement system used by the laboratory.

What Foods Should Be Avoided Before a CT Scan?

There are generally no dietary restrictions. However, for abdominal CT scans, fasting is required for at least 4 hours before the procedure. For examinations of other body regions, no special dietary limitations are necessary.

How Long Does a CT Scan Take?

The procedure begins with a planning scan to determine the patient’s position and define the scanning area. This takes a few minutes. If the examination is performed without contrast, the actual scan lasts only a few seconds and usually requires a single breath-hold. If contrast is used, arterial, venous, and delayed phases may be added, each lasting a few seconds, with intervals ranging from 20 seconds to 10 minutes. Overall, a CT scan without contrast takes about 3 minutes, while a contrast-enhanced CT scan typically takes 15–20 minutes.

How Long Does It Take to Receive CT Results?

The visual data (on a CD or USB flash drive) is usually available within 10–15 minutes. The radiologist’s written report is generally ready within 2–3 hours, although in urgent cases this time may be significantly reduced.

How Often Can a CT Scan Be Performed?

Modern CT scanners use a minimal radiation dose — only a few mSv, compared to the generally accepted annual limit of 50 mSv. The interval between examinations is also important. Several CT scans performed in a short period may carry a higher cumulative dose than studies spaced over several months. In serious conditions such as cancer or multiple trauma, CT scans may be performed as often as clinically necessary.

How Does CT Affect the Body? What Is the Radiation Dose?

CT uses ionizing X-ray radiation, which can affect body cells. However, the scanning process itself lasts only a few seconds. Modern scanners provide a low radiation dose — approximately 2–3 mSv per scanned region, which is considered safe for most patients. The exact dose depends on the body area examined, the patient’s body size, and the length of the scanned region.

What Should Be Done After a CT Scan?

No special measures are needed after a CT scan to “remove radiation.” If contrast was administered, it is recommended to drink more fluids to help the kidneys eliminate the contrast agent more quickly. Breastfeeding women are advised to express breast milk for 24 hours after the procedure and feed the baby with previously stored milk or formula during this period.