How is MRI different from CT? What to give preference to: computed tomography or magnetic resonance MRI and tomography, what is the difference

As you know, in the modern world there is a huge amount of diagnostic tools that allow you to make a diagnosis as soon as possible and with high accuracy. These tools include CT (computed tomography) with MRI (magnetic resonance imaging), which make it possible to look into the depths of the human body and see everything that happens to tissues and internal organs. What are the differences between these methods, when they are required, what contraindications and indications do they have, which one is safer for a person? Let's try to deal with this issue.

Operating principle

Despite the fact that CT and MRI provide the same high-quality three-dimensional image of the studied tissues and organs, the difference between them is huge - they differ both in terms of sensitivity and the principle of operation.

A CT scanner uses x-rays to take pictures. The device makes rotational movements around the subject, taking pictures, which are subsequently processed by a computer.

Magnetic resonance imaging, meanwhile, uses magnetic fields in its work that have a certain effect on hydrogen atoms in the human body, as a result of which the latter line up parallel to the direction of the fields themselves. During the examination, the device sends an impulse perpendicular to the main magnetic field, as a result of which the tissues of the human body enter into resonance, and the cells begin to oscillate. The vibrations are transmitted to the tomograph, which, after recognition and processing, creates multidimensional images.

Difference in readings

It is quite natural that the difference in the principle of operation of the equipment determines its purpose. So, magnetic resonance imaging, as a rule, is prescribed when it is necessary to study the nervous system, soft tissues, joints and muscles. But the skeletal system in the resulting images will be poorly distinguishable. This is explained, first of all, by the fact that bone tissue contains few hydrogen protons and, accordingly, responds poorly to magnetic radiation.


Thus, if it is necessary to study the human skeletal system, it is better to perform computed tomography, which, in addition, will describe the state of hollow organs, for example, the intestines and stomach, as well as the lungs, much better than MRI.

If we talk about diseases, then MRI is best done in the presence of:

  • diseases of the pelvic organs and spine;
  • strokes;
  • diseases of the trachea, blood vessels and esophagus;
  • pathologies of the main vessels of the brain;
  • multiple sclerosis and encephalomyelitis;
  • cystic and tumor processes of the spine;
  • inflammatory processes in the brain and neoplasms in it;
  • inflammatory changes in the spinal cord;
  • intervertebral hernias.

As for CT, it is better to use it in the presence of diseases:


The difference in contraindications

Just like most modern diagnostic tools, computed tomography and magnetic resonance imaging have their own contraindications, which have some differences from each other.

So, CT cannot be used to examine:

In addition, CT should not be used frequently.

As for MRI, the number of contraindications to this procedure includes:

What are the benefits

The main advantages of MRI include:

  • high accuracy of research;
  • the possibility of multiple holding;
  • painlessness;
  • the possibility of obtaining three-dimensional images;
  • the ability to save data in the computer's memory;
  • exclusion of the possibility of obtaining erroneous information;
  • no exposure to x-rays.

The main advantages of CT include:

What are the disadvantages

The main disadvantages of MRI include:

  • the impossibility of a qualitative study of hollow organs;
  • the impossibility of research in the presence of metal implants;
  • the duration of the procedure.

The main disadvantages of CT include:

  • the impossibility of obtaining information about the functional state of the studied tissues and organs;
  • the presence of harmful radiation;
  • limitation on the number of procedures per year;
  • the impossibility of conducting research in pregnant women and children.

Summarizing the above, we can say that CT and MRI are completely self-sufficient methods that have significant differences from each other and allow obtaining comprehensive information about the studied tissues and organs of the human body - the spine, pelvic organs, chest, bone tissues, etc. Thus, in some cases it is worth preferring MRI, in others - CT, in the third - MRI and CT together.

And, of course, the answer to the question of which is better, MRI or CT simply does not exist.

With the advent of the 21st century, medicine has risen to a very high level of progress, having mastered many types of complete examination of the human body. Today, high-tech methods such as CT and MRI are used for these purposes. Read about here.
But often, the patient has a natural question, what is the difference between these types of diagnostics and which one is safer, more effective and preferable. Let's try to understand this dilemma by comparing both methods.

What is CT?

CT (computed tomography) - the principle of diagnosing the body, with which it is possible to obtain clear and detailed images of the necessary internal organs. The examination is carried out using x-rays, or more simply, rays.

In many healthcare institutions in Russia, it is X-ray CT that is the most popular and primary type of examination of human organs.

It is worth noting that this diagnostic method appeared in the world not so long ago, but quickly took a leading position and was recognized by all experts, which makes it possible not to doubt its quality.

CT scan was developed in 1972 two scientists Godfrey Hounsfield and Allan Cormack, who received the Nobel Prize for their discovery.

The principle of operation of CT

Computed tomography does not take much time, its principle of operation is quite simple. During the examination, the patient is placed on a special table, synchronized with a scanner resembling a large ring. The scanner rotates and passes rays through parts of the body.

During this process, a picture of the studied organ in a section is displayed on the doctor's monitor. After that, a picture is taken, which can be printed and studied in more detail. The whole procedure usually takes 5 to 20 minutes. during which a person should lie in a calm state, without making sudden movements.

How to prepare for CT:

  • in the evening do not eat solid food;
  • do not drink alcohol the day before the procedure;
  • consult a doctor in advance;
  • remove clothing.

The tomography process itself is usually carried out by a specialist radiologist, who then issues a conclusion. However, a decoding of the diagnosis can only be obtained from a radiologist, as well as a general practitioner or surgeon.

When is CT used?

X-ray computed tomography helps to see almost any internal organ and part of the body, identifying disorders or pathologies in them.

With the help of CT, you can examine:

  1. limbs- will determine violations in the hands, shoulders, knees, etc.
  2. spleen- will show irregularities in functioning or size.
  3. Liver- detect tumors and bleeding of the liver.
  4. chest- helps to find diseases of the heart, lungs, esophagus and aorta.
  5. abdominal cavity- examine the esophagus system, determine cysts, tumors, bleeding, inflammation.
  6. Bladder- It is mainly used to identify kidney stones and urinary tract obstruction.
  7. Pancreas and gallbladder- will find stones or indicate obstruction of the bile ducts.
  8. adrenal glands- you can determine the tumor or changes in size.
  9. Pelvic area.
  10. Spine.

Among other things, CT is able to study such complex parts of our body as blood vessels, blood flow, but, most importantly, X-rays are used to determine tumors and the stage of cancer, showing the spread of metastases.

Contraindications

In almost any case, before you go to see the radiologist and agree to a CT scan, need to consult with a therapist. After all, although this diagnostic is used everywhere, it has some contraindications.

Complications after CT scan:

  1. Allergic reaction.
  2. Health problems in people with diabetes.
  3. Slight risk of failure of implanted medical devices.
  4. Panic when suffering from fear of closed spaces.

With caution and only with the permission of a doctor, the CT procedure should be performed by pregnant women, allergy sufferers, diabetics, asthmatics, and claustrophobia.

There is an opinion that CT, due to radiation harmful to humans, causes cancer, especially in those people who are susceptible to this disease. However, this version is still disputed and does not have a definite answer.

What is an MRI?

MRI (magnetic resonance imaging) - helps doctors get inside the human body, seeing this or that part of the body, in order to determine violations in it or to establish a disease associated with the pathology of a particular organ.

Tomography excludes physical interference in the body, but with the help of a unique research technology - nuclear magnetic resonance - it allows you to very clearly see even microscopic disorders in both organs and tissues of the human body.

MRI was developed around the same time as CT. The world heard about a new type of diagnostics in 1973, however, it was built on completely different principles than computed tomography, but it was also an effective and safer examination tool.

How MRI works

Magnetic resonance imaging is a rather complicated process of examining the body. He can take from 30 minutes to 2 hours. During the procedure, the patient is placed on a special table, which is then pushed into the scanner-capsule.

The powerful magnet and RF coil inside the structure of the scanner will cause the person to resonate or emit weak radio signals which are collected by the scanner. According to the emitted signals, the doctor will be able to determine whether the organ is healthy or has abnormalities. Then these signals are processed by a powerful computer, issuing image of the desired organ - tomogram.

Preparation for an MRI includes:

  • do not eat solid food in the evening;
  • before the procedure, remove all jewelry and accessories;
  • remove patches;
  • inform the doctor if there are implants in the body;
  • if part of the clothes is left, you need to empty the pockets.

MRI is not the most pleasant procedure, during which, most often, the patient is placed on his back and pushed into the capsule. Sometimes, it is necessary to fasten the patient with belts so that he is motionless - this is a very important point. In addition, the tomograph makes various noises that are not very pleasant for a person; in some clinics, headphones with music or ear plugs are issued. During the test, the patient may be asked to hold their breath, close their eyes, or not move.

There is another MRI scanner, the so-called lightweight version, which is suitable for people suffering from claustrophobia - the fear of closed spaces. This is an open view scanner where the patient is not placed in a capsule. But this type of diagnostics is not so common in Russia, and therefore it is quite difficult to find a clinic with such equipment. In addition, the quality of the tomogram (image) will most likely not be as good.

When is MRI used?

MRI may not be used in all cases, as some complications can only be determined by a CT scanner with x-rays. However, the most popular diagnoses with which patients come to the doctor are quite simple to identify using the magnetic resonance method.

MRI diagnostics allows you to examine:

  1. Brain- bruises, changes in cerebral fluid, tumors.
  2. All parts of the spine– pathology of the spine, trauma.
  3. joints- infections and lesions.
  4. Vessels- pathologies.
  5. Abdomen- Ulcers, bleeding, tumors.
  6. Liver– inflammation, bleeding, stones
  7. Rib cage- heart disease, cardiovascular disease, changes in the respiratory organs.
  8. Bladder- stones, obstruction.

MRI can also detect such a terrible disease as a malignant tumor. At the same time, the device will show the first symptoms when cancer is just beginning to develop in the body.

Answer to the question: - read here.

Contraindications

Until now, the effect of the magnetic field used in MRI on humans has not been fully studied. It is only known that this magnet is very powerful. In this connection, doctors do not recommend MRI, for example, for people with metal implants in the body.

In addition, there are such contraindications as:

  • iron tattoo pigments;
  • Permanent makeup;
  • medical plasters on the body;
  • claustrophobia;
  • pacemakers and other medical implants;
  • dental crowns.

Allergy sufferers, people with heart failure, hearing loss and pregnant women should also consult their doctor before taking an MRI capsule.

Distinctive features of CT and MRI

Computed and magnetic resonance imaging to date have equally reached their peak of perfection. These are high-tech methods of flat examination of the human body, used in almost all medical institutions. Both methods allow diagnosing almost all parts of the body., organs and tissues, as well as display high-quality images of the examined area.

However MRI and CT have completely different methods of influencing the human body. The equipment used for both types is radically different in principle of operation, device and structure. Patients are increasingly choosing a computer method, while doctors recommend magnetic resonance.

Their fundamental difference:

  • MRI is based on the work of a magnetic field, and CT is based on x-rays;
  • MRI determines the chemical composition of the examined part, and CT sees the physical state;
  • MRI examines predominantly soft tissues, and CT examines the skeleton;
  • MRI is performed in a closed capsule, where the person is completely placed, and with CT, only the necessary part of the body is placed in a closed area;
  • MRI is a time-consuming procedure, and CT is done much faster;

It is believed that MRI is a safer procedure for the body, which excludes radiation by rays, therefore, magnetic examination can be performed more often than a computer one. However, even here a controversial issue arises, because the effect of a magnetic field on a person has not been fully studied by medicine.

Advantages and disadvantages of MRI and CT

Patients, choosing a diagnostic method for themselves, often pay attention only to the advantages of the procedure: its low cost, availability of the device in the nearest clinic, quick results. But it is worth paying attention to the shortcomings, which in the end can give an inaccurate result and lead to complications.

Advantages of CT:

  • fast;
  • inexpensive;
  • excellent examination of bone structures;
  • high quality image of the skeleton;
  • comfort of the procedure.

Disadvantages of CT:

  • difficult to determine the early stage of cancer;
  • soft tissues are difficult to see;
  • radiation from x-rays;
  • contraindications during pregnancy.

Advantages of MRI:

  • excellent examination of soft tissues;
  • the availability of the procedure, which is done in almost all clinics;
  • impact on the body not by radiation, but by radio waves;
  • detection of a tumor at an early stage;
  • the image is not only transverse, but also longitudinal sections.

Disadvantages of MRI:

  • inability to detect certain bone pathologies;
  • the procedure takes too long;
  • high cost;
  • the impossibility of examining people, for example, with claustrophobia.

Which is better: CT or MRI?

It is impossible to answer this question unequivocally., because in medical practice there are many cases when patients had to do two research methods at once in order to identify all the shortcomings of the body. This suggests that one type of diagnostic can both replace another and supplement it. So, when detecting cancer, two methods can be used at once - one will show the number of metastases, the other - the tumor itself.

Both the patient himself, depending on his personal preferences, and the attending physician, who will surely determine which scan will be most effective in a particular case, can choose between MRI and CT.

Modern diagnostic methods make it possible to identify various pathologies and disorders in the functioning of organs and systems at the very beginning of their development. Today it is impossible to imagine the development of modern medicine without the use of such types of examinations as and.

They are non-invasive methods for diagnosing various disorders and diseases in the human body, and it is often quite problematic for the patient to decide which one to give preference to. In fact, if it is necessary to examine the patient, MRI and CT are often prescribed, but there is a difference between them and it is quite significant.

Medical practice shows what is prescribed for the diagnosis of changes of a different nature occurring in soft tissues. In addition, thanks to this research method, it is possible to visualize the spinal cord and brain, as well as other internal organs.

The advantage of this diagnostic method is the fact that MRI allows you to obtain a high-quality image, which cannot be said about procedures such as X-ray examination, computed tomography and ultrasound.

Thanks to early MRI, it is possible to detect the progression in the human body of such complex and dangerous pathologies as:

  • musculoskeletal disorders
  • oncological diseases
  • neurological disorder

Especially often used to examine the central nervous system and. Thanks to this research method, a specialist is able to assess the structure of organs, diagnose existing diseases and malignant neoplasms. MRI is widely used in such branches of medicine as:

  • urology
  • oncology
  • angiology

MRI is widely used not only for the study of internal organs and tissues, but also for non-invasive study of the work of internal organs. Thanks to this procedure, the following studies can be carried out:

  • speed current measurement
  • blood flow assessment
  • determination of the level of diffusions in tissues
  • control of cortical activation

This means that with the help of magnetic resonance imaging, it is possible to assess several aspects of a person's state of health in one session.

Features of MRI

The MRI procedure is considered completely painless, and in order to obtain accurate and reliable results, it is recommended that certain rules be followed. During the study, the patient is on the table in a horizontal position and is gradually moved into a narrow tube.

A strong magnetic field is created inside such a device, depending on which organ is being examined. To obtain accurate and informative images, the patient must be in a stationary position during the examination, since the slightest movement can distort the result.

The procedure itself is not accompanied by any painful sensations, and only a strong noise that is generated during the operation of the medical device can cause discomfort. In order to reduce noise, a person is offered to use special headphones.

MRI is a diagnostic procedure that does not require any rigorous preparation.

The patient can lead a normal life before the study, do not limit himself to food and drink, and take the necessary medications.The only thing to remember is that if you need to examine the bladder, you must first fill it with a sufficient amount of fluid. In the event that it involves examining the patient's head, it is recommended to refuse to apply various cosmetic preparations and makeup to the skin.

This need is due to the fact that any cosmetics can adversely affect the quality of the image and thereby reduce the accuracy of the study. Before the MRI, the patient must take with him all the previous results of the examination and be sure to show them to the specialist. This will allow the doctor to assess the entire clinical picture of the patient and track the dynamics of changes in his state of health.


In fact, MRI has long established itself positively in medical practice. This method of research combines safety for health, painlessness and high information content of the images obtained.

This procedure is a non-invasive diagnostic method, which completely eliminates the need for surgical intervention.

There is a division of MRI diagnostics into several types, taking into account the examined part of the body:

  • widely used in the field of neurology and neurosurgery. With the help of this diagnostic method, it is possible to identify with high accuracy various disorders and abnormalities localized in the brain area. MRI can be performed immediately before surgery, which allows you to determine specific areas of intervention and its extent.
  • often performed in urology and gynecology for the diagnosis of various female diseases. This type of study is used in men to identify and examine organs such as the penis and testicles.
  • helps to diagnose various types of pathologies of the spinal cord and spine. Thanks to this diagnostic method, it is possible to accurately determine the focus and size of spinal injury, malignant neoplasm and intervertebral hernia.
  • used in the field of orthopedics, traumatology and surgery. Using this procedure, a specialist can easily assess the condition of ligaments, tendons, acne and joint capsules.
  • MRI of the abdominal cavity provides data on the state of all organs. Thanks to such a study, it is possible to diagnose various pathologies at the very beginning of their development.

In addition, an MRI of the whole body can be performed by a specialist, and this is most often practiced in the field of oncology. This diagnostic method is assigned to those patients who want to get a complete clinical picture of their health in just one procedure.

Contraindications for MRI

Despite the effectiveness of this procedure, not all patients can resort to it.

There are a number of contraindications for MRI:

  • the presence of a pacemaker and metal implants in a patient
  • period
  • claustrophobia
  • the presence of non-ferromagnetic implants and prostheses
  • insulin pumps

In addition, a relative contraindication to MRI may be the presence of tattoos on the patient's body, which are made using various dyes.

The procedure is carried out in a rather narrow space and patients with claustrophobia may experience great discomfort. To obtain accurate and informative results, a long stay of the patient in a stationary state is necessary, therefore, if it is necessary to conduct a study in childhood, anesthesia can be used.

CT: description and types

Computed tomography is currently considered the leading method for diagnosing various organs and systems.

Such a procedure can be carried out as a method of primary diagnosis, and also used as a clarifying technique to confirm the diagnosis with the help of a clinical examination.

CT is prescribed for research:

  • chest
  • organs of the urinary system
  • gallbladder and ducts
  • limbs
  • adrenal glands

In some cases, computed tomography is prescribed to control the correctness of medical procedures. In patients with oncological diseases, this diagnostic method makes it possible to determine the stage of a cancerous tumor, because it can be used to see the area of ​​\u200b\u200bdistribution of metastases.

Useful video - What is better MRI or CT:

Before the CT scan, the patient needs to undress to underwear and get rid of jewelry. During the procedure, the person is positioned on a table that slowly slides through a part of the tomograph in the form of a ring. This part of the drug rotates around the part of the body that is being examined and takes the appropriate pictures.

During the CT scan, you must be in a stationary state, and the device may make an unpleasant noise.

During the procedure, it can be used, which is injected into the patient's body intravenously or through a catheter. In some cases, when examining the abdominal cavity, the contrast agent is offered simply to drink.

Contraindications for CT

In fact, there are no absolute contraindications for CT. Such a procedure can be prescribed to a patient of any age, and even if the patient is on mechanical ventilation.

In the event that there is a need for CT during pregnancy or in childhood, then it is necessary to carefully weigh the pros and cons. The fact is that CT is accompanied by an insignificant radiation load on the body, and the consequences of such exposure have not yet been sufficiently studied.

Often the procedure is carried out with the introduction of a contrast agent into the human body, which allows you to get more accurate information about the state of the organ under study. In fact, such a contrast agent can provoke the development of an allergic reaction in a patient, so its introduction into the body must be justified. In the event that it is necessary to conduct a CT scan with just such a substance, then antiallergic actions are preliminarily performed by a specialist.


The main difference between MRI and CT is the principle of operation of tomographs. is based on the work of a magnetic field and on measuring the responses of a hydrogen atom under its influence. If it is necessary to carry out computed tomography, the principle of operation lies in x-ray radiation.

CT can produce a three-dimensional image, but this procedure can be dangerous for the patient's health. MRI is considered a completely harmless research method that can be used even during pregnancy.

CT and MRI are widely used to diagnose various types of pathologies, as well as to confirm existing diagnoses.

The difference between the two types of such diagnostics lies only in the cost of the procedure and in the side effects that occur after a CT scan. It is for this reason that when choosing a diagnostic method, you should carefully weigh all the nuances and choose between the price of research and safety. MRI is considered a safer procedure, but at the same time, CT is more affordable.

Before identifying the difference between MRI and CT, it is necessary to understand what these two types of diagnostics are.

CT (computed tomography) is a sequential scan, both of individual areas of the body, and completely (general scan) by means of X-ray irradiation. There are two types of scanning - with a substance (contrast) and ordinary, without the involvement of additional substances and equipment. The procedure is carried out using a capsule, spiral tomograph, the number of spirals (4, 8, 16, 64) directly affects the object of diagnosis (heart, intestines, brain).

MRI (Magnetic Resonance Scanning) is the best diagnostic tool for monitoring soft tissue. In the description of the diagnostic method, the answer to the first question is immediately found: “What is the difference?” - X-ray radiation is not used, a picture of the state of the body is obtained through a magnetic field and the position of radio frequencies. During the procedure, a person is placed in a special capsular, closed tunnel, in which he is scanned.

What is the difference between CT and MRI:

What is the difference between CT and MRI - contraindications

As with any examination method, MRI and CT have their own number of contraindications that prohibit the procedure.

When is it better to refuse magnetic resonance therapy:

If there is a need to undergo a CT examination, no doctor will refuse you, because the technique has no contraindications. It is prohibited only in rare, purely individual cases.

The second difference is the difference in contraindications or their complete absence in CT (except for pregnancy and allergy to contrast).

Difference in preparation between CT and MRI

Before CT, you must strictly refuse to take food and liquids (3-4 hours in advance). The exception is the study of the digestive tract.

Before an MRI, it is always necessary not to eat for 3-4 hours. Before the actual procedure, it is necessary to remove metal objects and removable implants for diagnostic accuracy and safety for the patient.

What is the difference between CT and MRI - how to prepare for the diagnosis.

Conducting CT and MRI referral procedures

While visiting the MRI diagnostic room, you take off things that are harmful for diagnostics, you may undress to the waist. Lie down on the retractable table of the apparatus and you are loaded into the tunnel.

The examination is quite long (25-40 minutes), there is little space inside, so it is better for those suffering from claustrophobia to refrain. The device has a built-in video transmitter and a special microphone for communication with the doctor. The results are ready in a day, you can pick them up yourself, or your doctor will have them. Sometimes an injection of a special solution (5-15 ml) is required to highlight the organ (MRI with contrast).

Before CT there is no rigid framework regarding implants, prostheses. The patient lies on a mechanical couch, which is directed to the tomograph in different ways. There is a lot of space left, so bouts of claustrophobia are excluded. The duration of the procedure is a maximum of 10 minutes. Results are obtained almost immediately.

If we talk about the specifics of the methods, the main differences between them are: the speed of the examination (CT takes less time), the speed of obtaining the result, the amount of free space (especially important for those suffering from claustrophobia) and the type of equipment.

Disadvantages of MRI and CT - where to look for their weaknesses?

Modern medicine is quite developed, but there is no such diagnostic in the world that is 100% perfect, each is endowed with its own advantages and disadvantages.

Errors of MRI diagnostics:

  • A large list of contraindications, the impossibility of carrying out in the presence of any artificial material in the body (false teeth, pacemaker, limb prosthesis, piercing).
  • The duration of the procedure (25-40 minutes).

The negative side of CT diagnostics:

  • The use of X-rays, although not very harmful, is irradiation.
  • Inability to study the entire spine (requires too high a dose of radiation).
  • It is strictly contraindicated for pregnant women.

The next difference is that MRI is harmless, but contraindications may prevent the appointment of the procedure, it lasts longer than CT. And computed tomography is not suitable for the spine and is not completely harmless.

Difference between CT and MRI appointments

For a comparative analysis, it is important to know which diseases can be detected by each of the methods.

Indications for computed tomography:

  • Violation of the musculoskeletal system and diseases of the joints. Helps to identify arthrosis, arthritis, ankylosing spondylitis, osteochondrosis and more. Despite the fact that it is impossible to completely scan the spine. The technique remains one of the most accurate, the first when a violation of the bone apparatus is detected.
  • Tumors, growths, bone deformation.
  • Injuries, damage to the human skeletal body - fractures, cracks in the bones, dislocations, deviations due to mechanical impact - are detected after receiving the results.
  • Changes in the structure, work of blood vessels at the atherosclerotic level.
  • When examining the soft tissues of the respiratory apparatus, the gastrointestinal tract and the genital, urinary organs, a contrast study is performed.

When is magnetic resonance therapy needed:

  • If tumors, cysts, growths of soft tissues (muscles, organs, adipose tissue) are suspected, the procedure is prescribed only after the initial examination and preliminary results of ultrasound examination.
  • To control the state, the quality of the brain (not only physical factors, but also mental ones). For example, in people with schizophrenia, there is a strong activity in the area of ​​​​the brain responsible for hearing and vision - this indicates hallucinations.
  • To detect disorders of the spinal cord.
  • To detect pathologies of the soft cartilage of the vertebrae and intervertebral discs.

This difference indicates the exclusivity of each of the methods - they are very different and each of them is required for certain pathologies.

How is CT different from MRI - which is better?

A difficult question, because each of the diagnostics is good in its “business”. So which is better MRI or CT?

MRI provides more accurate results in diseases and is recommended if:

CT will be more effective when:

  • Mechanical damage, trauma to the brain and cranium.
  • Damage to the bone apparatus, its deformation due to mechanical impact.
  • Study of the vascular system, heart.
  • Purulent diseases - sinusitis, otitis.
  • Pathologies in the abdominal cavity.
  • Negative changes in the respiratory organs - bronchi, lungs.
  • Cancer, degenerative changes in the chest and its organs.

If a full-fledged study of soft, connective, adipose tissues is required, then it is better to choose MRI.

It is harmless to the body and does not charge the body with a small dose of radiation, like computed tomography. An excellent replacement for contrast CT, if individual intolerance, contraindications are detected.

CT has a more intense effect on the body, but if you want to examine the musculoskeletal system, respiratory system, abdominal cavity, it becomes a choice.

It is impossible to say that it is better, but they are different. These are two completely different research methods, which differ in the type of contraindications, indications, method of exposure. According to the characteristics of these diagnostics, as well as the anamnesis, the doctor decides which type of examination will be effective in your case. The main thing is to be regularly examined and monitor your health.

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CT differs from MRI in terms of how it works. At the discretion of the doctor, one or another procedure may be prescribed. Depending on which area of ​​the body should be examined, the diagnostic method is also selected. Also, in many respects, the diagnostic method depends on how many times in a short period of time it will be necessary to conduct an examination. Each of the methods has its own advantages and disadvantages. It is useful to know them for a patient who must undergo a diagnostic examination using a computer or magnetic resonance tomograph.

Both methods are highly informative and allow you to very accurately determine the presence or absence of pathological processes. There is a fundamental difference in the principle of operation of the devices, and because of this, the possibility of scanning the body with the help of these two devices is different. Today, X-ray, CT, MRI are used as the most accurate diagnostic methods.

Computed tomography - CT

Computed tomography is performed using x-rays and, like x-rays, is accompanied by irradiation of the body. Passing through the body, with such a study, the rays make it possible to obtain not a two-dimensional image (unlike an x-ray), but a three-dimensional one, which is much more convenient for diagnosis. Radiation when scanning the body comes from a special ring-shaped circuit located in the capsule of the device in which the patient is located.

In fact, during a CT scan, a series of sequential x-rays (exposure to such rays is harmful) of the affected area is performed. They are performed in different projections, due to which it is possible to obtain an accurate three-dimensional image of the area being examined. All images are combined and turned into a single picture. Of great importance is the fact that the doctor can look at all the images separately and, due to this, study the sections, which, depending on the device settings, can be as thin as 1 mm, and then also a three-dimensional image.

Thus, during a CT scan, the patient receives a certain dose of radiation, as with an x-ray, which is why the procedure cannot be called completely safe.

Magnetic resonance imaging - MRI

Magnetic resonance imaging also provides a three-dimensional image and a series of images that can be viewed separately. Unlike CT, the machine does not use X-rays and the patient does not receive any radiation dose. Electromagnetic waves are used to scan the body. Different tissues give different responses to their impact, and therefore an image is formed. A special receiver in the device captures the reflection of waves from tissues and forms an image. The doctor has the opportunity to enlarge, when necessary, the picture on the screen of the device and see the layer-by-layer sections of the organ of interest. The projection of the images is different, which is necessary for a full examination of the area under study.

Differences in the principle of operation of tomographs give the doctor the opportunity, when detecting pathologies in a particular area of ​​the body, to choose the method that in a particular situation can provide more complete information: CT or MRI.

Indications

Indications for conducting a survey using one method or another are different. Computed tomography reveals changes in the bones, as well as cysts, stones and tumor formations. MRI also shows, in addition to these disorders, also various pathologies of soft tissues, vascular and nerve pathways, articular cartilage.

Indications for MRI Indications for CT
Soft tissue tumors and suspicion of their presence Bone damage, including jaw and teeth
Determination of the state of nerve fibers in the internal organs, as well as the brain and spinal cord Determination of the degree of damage to the joints in injuries and chronic diseases
Determination of the state of the membranes of the spinal cord and brain Identification of diseases of the spine, including intervertebral hernias, osteoporosis and scoliosis
The study of the state of the brain after a stroke and in multiple sclerosis Determining the degree of brain damage in tumor diseases and injuries
Determination of the condition of muscles and ligaments Determination of the state of the chest organs
Determination of the condition of the joints Definition of neoplasms in the thyroid gland
Inflammatory and necrotic processes in organ tissues and bone tissues Determination of changes in hollow organs
MRI of the lungs can be performed when establishing the presence of a tumor process even at the very beginning of its development. Determination of the presence of stones in the gallbladder and genitourinary system

In some cases, a computer or magnetic resonance tomograph can be used with an equal share of information content. Thus, depending on the equipment of the medical institution, the examination can be carried out using one or another type of equipment for scanning the state of the body.

Contraindications

Both scanning methods have some contraindications for use. In some cases, when the implementation of one method of research is not desirable or prohibited, the option of conducting a second one may be considered.

Contraindications for CT Contraindications for MRI
Pregnancy The presence of metallic elements in the body
Breastfeeding (if the procedure is performed, breastfeeding must be interrupted for 48 hours after the examination so that the child does not receive a dose of radiation) The presence of implanted electronic correctors of the work of internal organs and systems
Children's age (the only exceptions are cases when there is no other way to determine the patient's condition, and the benefits of diagnosis outweigh the risks of the procedure) Presence of an insulin pump
Patient weight over 200 kg First trimester of pregnancy
Nervous excitement in which the patient cannot remain still during the scan Weight over 130 kg
Frequent use Inability to stay still for as long as necessary for the procedure
Plaster cast at the site of examination Claustrophobia

In the contrast-enhanced procedure, the contraindications for both procedures are the same. This is due to the fact that the contrast agent has limitations for use. It should not be administered in the presence of severe renal and hepatic insufficiency, as well as in case of allergy to contrast.

If it is not known whether there is an intolerance to the agent, then a test for an allergy to a contrast agent is preliminarily performed. Several types of contrast can be used and, as a rule, it is possible to choose a tool that suits a particular patient.

How often can I scan

CT is performed using x-rays, and therefore frequent repetition of the procedure is not allowed. As a rule, it should not be carried out more than 1 time per year. If there is a cancer that requires regular monitoring, the minimum interval between examinations is 2.5 months. In this case, it is better to use MRI, in which there is no negative effect on the body of radiation, which is important for preventing complications. The procedure is not only safer, but completely harmless. MRI can be performed an unlimited number of times, and if necessary, even several scans in 1 day.

When using scanning with contrast, there are also no restrictions on the frequency of the procedure. The only thing to consider is the break between repeated injections of the drug. It is desirable to withstand at least 2 days to reduce the burden on the kidneys. The contrast agent does not cause harm to health. If it is used for CT, then all the limitations are directly related to the X-ray exposure, and not to the effect of the contrast on the body.

Is it possible to have an MRI and a CT scan on the same day?

The principle of impact on the body during examination using computed tomography and magnetic tomography is different, and therefore, when they are combined, the body does not receive an overload. If necessary, both types of tomography can be performed on the same day without fear for health. It's completely safe.

The difference between methods in the study of the brain

Brain scanning is necessary for many disorders, including strokes, circulatory disorders and tumor processes. If you need to take pictures frequently to monitor the condition, then MRI should be preferred, since it does not pose a danger if it is often repeated. Which method will be chosen depends entirely on the equipment of the clinic and the patient's contraindications and restrictions to the procedure.

According to CT and MRI, when studying the brain, they receive equally accurate results, and therefore there will be no differences in diagnosis. Both types of research will show tumors, vascular disorders and foci of inflammation. Additionally, MRI can also determine the density of brain tissue.

An important feature of magnetic resonance imaging is the ability to detect the focus of an ischemic disorder as early as 20 minutes before an acute condition of the patient develops. Because of this, if a pathology is suspected, it is an MRI that is performed.

What is best for lung scanning

If there is a suspicion that the fragments of the ribs have affected the lungs during the injury, then a CT scan is indicated, since this procedure will most accurately demonstrate the presence of bone fragments. The same scan is used for injuries to rule out or detect bleeding. Since computed tomography is performed especially quickly, it is the most optimal in emergency conditions. Also, the procedure allows you to very accurately determine the presence of metastases; CT of the lungs also shows secondary cancerous tumors.

MRI of the lungs is more often prescribed for tumor and inflammatory processes. Examination shows such changes in soft tissues very clearly and allows you to track the dynamics of their development without the risk of excessive exposure of the body.

Differences in the effect of tomographs on the body allow you to get maximum information.

What is optimal in the study of the abdominal cavity

There are no strong differences in the information content of the methods. The exception is that CT better determines the density of the tissues of the abdominal organs, and it is also possible to quickly establish the presence of solid formations and objects, bone fragments and bleeding. In case of traumatic injuries of the abdomen, CT is recommended, since the speed of the procedure makes it possible to identify dangerous violations in the shortest possible time.

MRI provides the most accurate information about the condition of soft tissues and the presence of inflammatory processes in the abdominal cavity. Because of this, the procedure is more often performed when examining the condition, pancreas, liver, spleen, intestines, etc.

What is more informative for diseases of the joints

In case of joint damage, including the hip joint, both CT and MRI are prescribed. Patients are naturally interested in which method is more informative and reliable. In case of disorders in the joints, magnetic resonance imaging is most often performed, which allows you to get maximum information about all tissues, including soft ones, inflammation of which is often accompanied by joint diseases.
In case of injuries or chronic pathologies, MRI can determine the condition of even nerve fibers, tendons, ligaments and blood vessels.

CT of the joints is used for injuries when the presence of damage to the bones or their heads that form the joint is suspected. During this procedure, bleeding into the joint cavity and the presence of bone fragments are quickly detected. Also, this study is carried out for diseases and injuries of the joints, if there are contraindications for magnetic resonance imaging.

If it is necessary to regularly monitor changes in the joint, then only MRI is used, since X-ray overload of the body poses a great threat. For children with problems with the joints, only an MRI is performed.

Which scan is best

Each of the methods is highly informative. The choice of which examination will be carried out depends on the contraindications and which tissues should be examined first. If there are suspicions of problems with the skeletal systems, the doctor chooses CT, and with soft ones - MRI. It cannot be said that one diagnostic procedure is better and the other is worse. Each method is more effective for obtaining certain information. More dangerous to health is CT, but if the examination is carried out correctly, x-rays will not cause negative consequences.

Where is it done and how much does the procedure cost?

The cost of the examination depends on the scanning area and what generation of equipment is used (the difference in price depending on the type of device can be quite large). The clinic in which the procedure is performed also matters. In state medical institutions, you can undergo a CT scan for 3-4 thousand rubles, and an MRI costs from 4 to 9 thousand rubles, depending on the organ being examined. The most expensive is a brain scan.

CT scan

Magnetic resonance imaging

The choice of diagnostic method remains with the attending physician. Both MRI and CT should only be done for medical purposes.

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