MRI for multiple sclerosis: features and interpretation

Talk about multiple sclerosis does not cease in the world of medicine. Many consider it a terrible incurable disease. However, this is not quite true. Yes, this disease really often leads to the development of disability, however, timely diagnosis of multiple sclerosis on MRI will allow you to prescribe an effective treatment on time, which will help achieve a stable remission of the disease.

Multiple sclerosis: what is it?

Multiple sclerosis is a chronic disease of the nervous system of autoimmune origin. Its essence is the development by the body of antibodies against its own cells. The main target is the nerve sheath (myelin), which, when destroyed, leads to a violation of the conduction of a nerve impulse along nerve fibers. The process of demyelination (destruction of the neural membrane) is clearly visible as foci of multiple sclerosis on MRI.

Main reasons

The exact causes of multiple sclerosis have not yet been elucidated. However, scientists were able to identify a number of provoking factors leading to its development:

• hereditary addiction;
• acute inflammatory diseases (viral, bacterial infections);
• chronic stress;
• brain and spinal cord injuries;
• diseases of the endocrine system.

Characteristic symptoms

In order to consult a specialist in time and diagnose "multiple sclerosis" by MRI, you need to know the main clinical manifestations of this disease.

Symptoms are conditionally divided into early and late. Early symptoms may be present not only in multiple sclerosis, but also in many other diseases. These include:

• dizziness;
• constant fatigue, weakness;
• visual impairment in both eyes;
• strange sensations in the extremities: tingling, creeping goosebumps on the skin (the so-called paresthesia).

Late symptoms are more specific and are more likely to prompt a doctor to refer the patient if they suspect multiple sclerosis on MRI:

• paresis and paralysis of the limbs (weakness in the arms and / or legs and their complete immobilization, respectively);
• nasal voice;
• memory problems
• dysphagia - difficulty swallowing food;
• impaired urination and defecation;
• breathing problems until its complete cessation due to paralysis of the diaphragm.

Clinical options

When foci of multiple sclerosis are visible on MRI, their number, frequency of occurrence over a certain period and other characteristics can be compared with the clinical course of the disease.

Therefore, it is necessary to know the main options for the clinical course of multiple sclerosis:

• primary progressive - with a gradual increase in clinical symptoms;
• recurrent - with alternating exacerbations, in which symptoms of the disease are observed, and remissions, when none are absent;
• secondary progressive - a combination of exacerbation and remission is also determined, however, with each new exacerbation, the symptoms worsen.

Multiple sclerosis: is it visible on an MRI?

Magnetic resonance imaging (MRI) is the most specific method for diagnosing multiple sclerosis. When conducting an MRI with multiple sclerosis, specific plaques (foci) of demyelination can be seen, that is, areas where the nerve is devoid of its membrane. Such foci have specific characteristics that make it possible to differentiate multiple sclerosis with other nervous diseases (stroke, discirculatory encephalopathy). And also to distinguish it from other autoimmune processes that affect the nervous system , including systemic lupus erythematosus, granulomatosis.

Diagnosis of this pathology using a magnetic resonance imager should be carried out by a highly qualified specialist who is able to distinguish foci of multiple sclerosis. In addition, you need a high-quality tomograph with high resolution, with which you can even see small foci.

MRI: principle of work

MRI is based on the difference in the concentration of hydrogen ions in water and lipids. The magnetic field that forms in the tomograph is able to capture this difference and create a contrast image on the basis of this. There are two modes of MRI - T1 and T2. They are distinguished by their contrast: the T1 mode depicts the white matter of the brain as light, and the T2 mode as dark. The foci of demyelination during the T1-mode of MRI are called "black holes", since they are darker than the normal white matter surrounding them . And in T2 mode they are bright white.

MRI can also be performed in two ways: without using contrast and with contrast. Contrast magnetic resonance imaging involves the introduction of a special substance into the peripheral vessels. Often this method is used when there is a suspicion of any obstruction in the vessel (thrombus, embolus) to visualize the vessel, its shape, location. However, contrast is also highly effective in the visualization of pathological plaques in multiple sclerosis.

Characteristic signs of foci of multiple sclerosis

In order to make a correct diagnosis in time, it is necessary to know the main signs of multiple sclerosis on MRI. These include:

• propagation in time and space - the number of foci increases when new tomograms are performed, new foci form in places not previously affected;
• swelling of brain tissue around foci of multiple sclerosis;
• characteristic localization of foci: brain stem, cerebellum, cerebral hemispheres, spinal cord, optic nerve;
• demyelination of nerves in the corpus callosum - the formation that connects the two hemispheres of the brain;
• when foci are formed along the radiant crown, a characteristic oval elongated shape is created.

These signs are characteristic both in the diagnosis of multiple sclerosis on MRI without contrast, and in contrast. However, there are characteristics that are visible only with the introduction of a contrast medium.

MRI with contrast: benefits

When imaging foci of multiple sclerosis on MRI with contrast, its accumulation will be characteristic in a ring-like manner around the focal point, which displays the active phase of autoimmune inflammation. That is, one of the advantages is the ability to determine the exacerbation of the disease, which may be asymptomatic.

In addition, MRI with contrast is more effective, since it allows you to see the smallest lesions that are not visible without the introduction of contrast.

With the introduction of contrast, the accuracy of diagnosis increases from 5 to 10 times.

Changes in MRI and a variant of the clinical course

Using MRI, you can not only diagnose multiple sclerosis, determine its stage (exacerbations or remissions), but also establish the duration of the disease and how it proceeds:

• The debut of the disease, that is, its onset, is visible 1 focus, usually large (about 2 cm) with blurry contours, oval or round. When performing several MRIs in dynamics, the reversibility of the demyelination process is visible.
• A remitting course lasting up to 1 year is a lot of foci, one of them is about 2 cm in size.
• Remittent course lasting up to 5 years - the number of foci increases, their size becomes larger or new foci appear with each new exacerbation.
• The primary progressive course - there are few foci, located in the area of ​​the horns of the ventricles, demyelination of corpus callosum neurons is rarely observed.
• Secondary progressive course - after a certain time foci appear, prone to fusion, in the paraventricular zone of the brain.

Diagnostic criteria

To simplify the diagnosis of multiple sclerosis on brain MRI and to systematize clinical data and data obtained using a tomograph, McDonald diagnostic criteria have been developed. Created in 2001, they change every few years, based on the medical experience gained.

Using these criteria, it is possible to quickly diagnose multiple sclerosis and start treatment on time.

The main criteria are presented in the table below.

All of the above signs on MRI with multiple sclerosis are necessary for diagnosis.

Treatment

A knowledge of all the symptoms and criteria for MRI in the diagnosis of multiple sclerosis is necessary for timely treatment, which will help prevent the further progression of this dangerous disease.

For quite a long time, the following two groups of drugs were used for the treatment of multiple sclerosis:

• interferons - this type of drug was used during the period of remission of the disease;
• glucocorticosteroids - drugs that are effective during an exacerbation of the disease, can reduce the autoimmune response of the body.

But over the past decade, scientists have developed new, more effective groups of drugs. First, new generation drugs appeared - biologically active agents - monoclonal antibodies. They are widely used not only in neurology, but also in other areas of modern medicine - in oncology, rheumatology, cardiology. They are really effective in the treatment of multiple sclerosis, and their use is very common in the treatment of this pathology.

Treating Multiple Sclerosis: 2011 Revolution

A real revolution in the treatment of this disease occurred in 2011, when scientists of the United States of America introduced a new drug with a completely different mechanism of action - “Fingolimod”.

What are its main advantages over other drugs for the treatment of multiple sclerosis? The first advantage is its ease of use. "Fingolimod" is the first drug for the treatment of multiple sclerosis with oral use, because all other drugs must be administered intravenously, which gives patients a lot of inconvenience. But the most important thing is how this drug affects the course of the disease. It can significantly reduce the risk of disability and literally stop the progression of the disease.

Fingolimod proved that with timely diagnosis of multiple sclerosis, it is possible to control and achieve stable, prolonged remission.

Thus, timely diagnosis of signs of MRI in multiple sclerosis, and a qualified interpretation of the results can save the patient's life. Indeed, today there are highly effective drugs that can significantly slow down or even stop the progression of the disease, providing the patient with a long and full life.