The 13 types of MRI (and their characteristics)

Diagnostic imaging tests are all those techniques that, through the use of electronic devices, allow visualizing the interior of the human body in order to look for signs (or confirm or refute) of the existence of any clinical pathology. These are very reliable and non-invasive techniques that allow obtaining internal information from the body without the need for surgical interventions.

Detect infections in the lungs, determine the presence of benign or malignant tumors, reveal ligament injuries, observe fractured bones, discover disorders at the level of the nervous system, look for signs of heart disease ... These and many other medical diagnostic tests would be impossible without all these techniques.

And in this context, the most important imaging tests are radiographs (X-rays are used), computed tomography (CT), ultrasound, nuclear medicine studies, and of course MRI. Each of them has different applications and nature. But today we will focus on the latter: magnetic resonance imaging.

Thus, in this article and, as always, from the hand of the most prestigious scientific publications, we are going to analyze all the important information about MRI, seeing what it is, how it works, what information it provides, what its risks are (if any), for what cases it is used and, of course, what types exist.

What are MRIs and what are they for?

An MRI is a diagnostic imaging technique that uses magnets and radio waves to obtain visual information from inside a person's body.. Also known as magnetic resonance tomography, it is a non-invasive test based on the properties of magnetism in order to have images that reveal the structure and internal composition of the subject to whom said test is applied.

As we say, it is the diagnostic imaging test based on magnetic properties. Its operation is based on using a large magnet and radio waves, which affect the person to obtain images of their soft tissues. It is a kind of scan in which the person lies on a table that slides into the resonance apparatus, which is shaped like a tunnel.

Magnetic resonances are used to diagnose diseases associated with the abdomen, pelvis and chest, at the same time as it helps to detect the existence of disorders such as ligament, meniscus and tendon ruptures, muscle pathologies, benign and malignant tumors (cancer ), neurological diseases (associated with the brain and spinal cord), etc. In essence, MRI is useful to detect pathologies in the soft tissues of the body, an area where other imaging tests do not respond as well.

In addition, it is a very safe technique (like all diagnostic imaging tests, but this one especially) that does not present risks beyond the fact that the person has some metallic component in the body such as pacemakers, metallic prostheses, implants, surgical staples ... Let us remember that it is based on using very powerful magnets, so the presence of metal on the person can pose a serious safety problem.

In addition, there are times when an MRI may require intravenous inoculation of what is known as contrast, a special dye that is injected in order to obtain clearer images. It is not dangerous, but there are people in whom it can cause allergic reactions that, with few exceptions, are mild.

An MRI lasts between 15 and 60 minutes depending on the area of ​​the body to be inspected and it does not cause any pain (beyond the discomfort of being in the enclosed tube), since a strong magnetic field is simply created and the signals of the radio waves are collected to translate them into images that will be displayed on the monitor. This is what MRI is based on.

What kinds of MRIs are there?

After having defined in a general way what this technique consists of, we already have an idea of ​​how MRI works. But it must be borne in mind that, depending on the pathology that we are looking for, this technique has to be adapted to the needs of each person. And it is that for each case, you will need a power, an inspection area and a specific time. For this reason, it has been important to differentiate the following magnetic resonance techniques. Let's see them.

1. Cervical MRI

Cervical MRI is one that is used to obtain images of the part of the spine that passes through the neck area. Typically a person undergoes this test when they feel severe pain in the neck, arm, or shoulder that does not improve with standard treatment, when neck pain is associated with leg weakness, numbness, or other clinical signs, when there is congenital defects in the spine, when there is an infection that involves the spine or with cases of severe scoliosis, as well as possible tumors in the spine.

2. Abdominal MRI

Abdominal magnetic resonance imaging is one that is used to obtain images of the abdomen area of the patient, obtaining detailed images from various planes of the entire ventral region. Normally a person undergoes this test when there have been abnormal results in blood tests that indicate liver or kidney problems, when there is a swelling of the abdomen of unknown origin or when there are suspicions of the presence of foreign masses in the organs of the region abdominal.

3. Cardiac MRI

Cardiac magnetic resonance imaging is one that is used to obtain images of the heart. It is usually used to diagnose symptoms of heart failure, congenital heart abnormalities, damage to the myocardium (the muscle tissue of the heart) after a heart attack, the presence of tumors in the heart, weakening of the heart muscle, etc.

4. MRI of the chest

Chest MRI is one that is used to obtain images of the thoracic region, that is to say, of the chest. Contrary to what one might think, it is not very effective in inspecting the lungs (a CT scan is better for this), but it is in detecting tumors in the chest, evaluating blood flow, observing the state of blood vessels and of the lymph nodes, clarify the results of CT scans or x-rays that have been done or see if a cancer in this region has spread.

5. MRI of the head

The MRI of the head is one that is used to obtain images of the brain and the nervous tissues associated with it. It is therefore used to diagnose and evaluate neurological pathologies associated with the brain, such as aneurysms, multiple sclerosis, cerebrovascular accidents, congenital anomalies, infections in the nervous system, cancers ...

They are also used to determine the cause of problems such as muscle weakness of unknown origin, changes in behavior, hearing loss, vision problems, headaches, speech difficulties, dementia, etc.

6. Magnetic resonance venography

Magnetic resonance venography is one that is used to obtain images of veins, the blood vessels that carry blood to the heart. It is usually used to diagnose thrombi (blood clots that form in the walls of a healthy blood vessel) and to see how their treatment is progressing.

7. Lumbar MRI

Lumbar MRI is one that is used to obtain images of the lower back area, that is, of the lumbar region. It is usually used in people who experience low back pain that does not go away with conventional treatment or when it is associated with weakness and numbness. It can also be applied when there are problems controlling bladder emptying, herniated discs, birth defects in the spine, etc.

8. Pelvic MRI

Pelvic MRI is one that is used to obtain images of the internal structures between the hip bonesi.e. bladder, reproductive organs, large intestine, intestine thin, prostate and other internal organs and soft tissues. Therefore, it is used when there are signs of pathologies in these structures or to monitor the progress of these diseases.

9. Magnetic resonance angiography

Magnetic resonance angiography is one that is used to obtain images of blood vessels usually. It is normally used to diagnose arterial aneurysms, carotid artery disease, aortic dissections, aortic coarctations, etc.

10. Musculoskeletal MRI

Musculoskeletal MRI is the most common of all and is the one used to detect abnormalities in muscles, tendons, bones, and ligaments of the organism. This includes MRIs of the knee, spine, ankle, hip, shoulder, elbow, wrist, etc.

11. Open MRI

Open MRI is one that it is not done inside the traditional tunnel and that can be contemplated for resonances of concrete parts of the body. If you are a person with claustrophobia, you can ask about the possibility of doing the MRI on one of these machines.

12. High-field magnetic resonance

High-field magnetic resonance imaging is the one with the highest power, thus allowing get better quality and more detailed images. Thus, it is useful to visualize smaller lesions and to inspect, very precisely, the state of internal organs that have previously been operated on. It is normally applied to the neck, head, abdomen, chest, knee and pelvis.

13. Joint MRI

Joint magnetic resonance is that resonance technique that, being also open, is intended for the inspection of upper and lower extremities. That is, it is the one used to obtain images of the knee, ankle, wrist, elbow and foot.