Magnetic resonance imaging and computed tomography. What do you need to know?

At first glance, it might seem that magnetic resonance imaging and computed tomography are almost the same examinations. The construction of machines used to carry them out is responsible for this impression. However, there are many more differences between these studies than there are similarities. So what is worth knowing about them?

What are the differences between these examinations?

These imaging examinations use different types of radiation. Magnetic resonance imaging uses the phenomenon of nuclear magnetic resonance using radio waves that are harmless to the human body. In contrast, computed tomography uses X-rays, which may be harmful with prolonged or frequent exposure. For this reason, it is recommended that the CT scan be performed as little as possible. Another significant difference is the technologies used, which affect the final cost of the examination – the more expensive examination is magnetic resonance imaging. The same factor affects the duration of the examination, which in the case of tomography is much shorter. When performing an MRI, the patient may also hear characteristic sounds. The combination of this factor with the duration of the test and limited space can be a challenge for people suffering from claustrophobia.

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What are the similarities?

Both of these tests do not cause any side effects, unless computed tomography is performed frequently, of course. The patient must remain motionless during both computed tomography and magnetic resonance imaging. This task can complicate the timing of an MRI scan. In the case of both tests, the so-called contrast, which is a special fluid that improves the visibility of certain organs. Its use is associated with the risk of discomfort for some time or the occurrence of allergic reactions. It is also worth bearing in mind that the substances used to contrast magnetic resonance images are much less likely to cause them. Contrast in the test is not essential, but it greatly improves the quality of the test.

Which test is the right one for me?

Both computed tomography and magnetic resonance imaging have their advantages and disadvantages, which mean that not every person can submit to them. An important issue in their case is the age limit from which these tests can be performed. The patient's age below 10 is a contraindication to performing computed tomography. In turn, in the case of magnetic resonance imaging, there are no such limitations at all and the examination can be performed even in young children. However, magnetic resonance imaging will not be possible for people with implanted medical devices that contain metal elements - a pacemaker, insulin pump, eye prosthesis, etc. In the case of computed tomography, the main contraindication, apart from age, is pregnancy. As far as the quality of the obtained images is concerned, the magnetic resonance imaging is much better, which is perfect for cases requiring detailed data on the patient's internal organs.

What are the benefits?

When performing both of these tests, you can get a complete picture of your body's internal structures. However, in the case of computed tomography, the acquisition of images is faster and enables the generation of an image of the structure of tissues, organs and the skeleton. MRI, on the other hand, is a skilled imaging tool that helps doctors determine if there are abnormal tissues in a patient's body. In addition, the MRI images are very detailed. It is worth bearing in mind that both tests can complement each other, thus giving a full overview of the patient's health.

Computed tomography or MRI?

A referral for an examination is issued by a doctor most often based on the patient's symptoms. If you need a good-quality picture of the soft tissue or organs to be clearly seen, then an MRI scan should be ordered. On the other hand, if, for further diagnosis, an image is needed that shows the internal organs more generally, then the patient is referred for computed tomography.