What is the difference between MRI and CT? Simply explained

MRI and CT are common diagnostic tools in medicine, but they have certain differences. What the methods are used for is explained here.

Difference MRI and CT: MRI diagnosis explained simply

Most patients associate an MRI examination with an unpleasant, lengthy and, above all, noisy examination. Magnetic resonance imaging, or MRI, works by using a magnetic field. During the 15-20 minute examination, the patient lies in a tube. This is how magnetic resonance therapy works:

• The patient is placed on a couch. This couch is then slid into the magnetic resonance scanner. If necessary, the patient is given a so-called contrast medium before the examination, which makes it easier for the doctors to evaluate the image later.
• The examination itself takes between 15 and 20 minutes. During the examination, the patient hears the knocking sounds typical of an MRI scanner.
• With this magnetic field, the tomograph “scans” the body and in particular the patient’s organs layer by layer.
• The diagnostic option MRI is used by doctors especially when organs are to be examined.
• According to experts, one advantage of this technology is that, in contrast to CT examinations, no harmful X-rays are used.

The CT method simply explained

Computed tomography, or CT for short, works in contrast to MRI diagnostics with X-rays. During the examination, the patient is also on a couch and in a machine. However, the duration of the examination is much shorter.

• Contrast media are also sometimes used in CT examinations. After administration, the patient lies down on a couch that is pushed into the CT scanner.

• The machine now carries out the examination using X-ray technology. The difference between this and a conventional X-ray examination is that with a CT the whole body is “scanned”.

• During the examination, which usually only takes a few minutes, the tomograph rotates around the patient to capture every view of the body.

• The cross-sectional images taken are now computer-assisted to form a 3D image.

• Computed tomography offers the advantage of a rapid examination and is therefore often used in emergency medicine. In addition, this form of diagnosis is particularly suitable for imaging the human skeleton.

• The disadvantage of CT is the use of X-rays, which can sometimes have a harmful effect on the human organism.

The harmful effects of X-rays in CT

Although CT offers many benefits, it is important to be aware of the potential harmful effects of X-rays.

• X-ray radiation is a high-energy form of electromagnetic radiation. It penetrates tissue and produces images by being absorbed by the various structures in the body. Although the radiation dose during a CT scan is relatively low, repeated exposure to X-rays over time can pose health risks.

• One of the main concerns with the use of X-rays is the potential damage to genetic material. X-rays are energetic enough to ionise the DNA in cells.
• It is important for doctors and radiologists to weigh the potential risks of X-rays when deciding to have a CT scan. In some cases, the benefits of an accurate diagnosis may outweigh the risks of radiation exposure.