Nowadays, in medicine, such types of research as CT and MRI are used. Both abbreviations for CT and MRI contain the word “tomography”, which can be translated as “slice examination”. Patients ignorant of modern medicine may perceive CT and MRI examinations as very similar procedures, but this is a mistake. Their similarity lies only in the generality of the procedure itself, as well as the application of the principle of layer-by-layer scanning with images displayed on a computer monitor. There is a big difference between CT and MRI. We will try to figure out what is the difference between CT and MRI and how this affects the results of diagnosis.
How is CT different from MRI?
Outwardly, they are the same: mobile tables and a tunnel in which the examined organs or another area of the body are scanned.
But the main difference between CT and MRI is that these studies use completely different physical phenomena.
Computed tomography (CT) is based on the use of x-rays. The scanner rotates around the examined area and displays images on the monitor from different angles. After computer processing, specialists receive a three-dimensional image of the desired area.
Magnetic resonance imaging (MRI) uses a magnetic field. The computer also processes the received information and produces three-dimensional images.
CT or MRI: which is better?
There is no point in discussing which method is better or worse: these are completely different methods that are used in different situations. Each research method has its own indications and. Each method is informative for certain organs and tissues in specific cases. In some cases, and with the complexity of diagnosis, it is even necessary or recommended to use both methods of tomography.
MRI allows you to see soft tissues more clearly, but does not “see” calcium in the bones at all. And CT allows you to study the bone tissue in more detail.
The passage of the MRI procedure is indicated for the study:
- Strokes, multiple sclerosis, inflammation of the brain tissue, brain tumors;
- , trachea, aorta;
- Ligaments, muscle tissue;
- and intervertebral discs;
- .
CT is prescribed for research and study: - Damage to the bones of the base of the skull, temporal bones, paranasal sinuses, facial skeleton, jaws, teeth;
- defeats;
- Organs ;
- Parathyroid and;
- and joints;
- Consequences of trauma.
When choosing a method for diagnosing diseases, the doctor also takes into account the patient's state of health and factors that may interfere with the tomography.
Despite obtaining the same results in both tomography (these are volumetric images), CT is harmful to human health. MRI diagnostics, on the contrary, is completely safe (even for pregnant and lactating women), but, unfortunately, more expensive.
The advantages of magnetic resonance imaging are:
- High accuracy of received information
- Patient safety, including
- The possibility of repeated use of the procedure if necessary, due to its safety
- Acquisition of 3D images
- The probability of getting an error during scanning is almost zero
- No additional contrast is required to study blood flow
- Great information content in the study of lesions of the central nervous system, the study of vertebral hernias.
Advantages of computed tomography:
- Reliable information
- Ability to obtain three-dimensional images of the study area
- Clearer images of the skeletal system
- The possibility of obtaining reliable information in case of internal bleeding, detection of tumors
- Short examination time
- The ability to undergo the procedure in the presence of metal or electronic devices in the body
- Small cost.
Disadvantages of CT and MRI studies
Of course, all types of research have both positive and negative sides.
The disadvantages of MRI include the following indicators:
- It is impossible to fully explore the hollow organs (urinary and gallbladder, lungs)
- It is impossible to carry out the procedure if there are metal objects in the patient's body
- To obtain high quality images, you need to remain still and calm for a long time.
The disadvantages of CT include the following indicators:
- Hazard to human health
- There is no way to get information about the functional state of organs and tissues, only about their structure.
- You can not undergo this tomography for pregnant and lactating mothers, children
- You can not undergo the procedure often
In any case, when visiting the attending doctor, the patient will be prescribed an examination, which is the desired and accurate result. If both methods of examination are assigned to you, then in this case the differences in the methods do not play a fundamental role.
Contraindications for tomography (CT and MRI)
Each of the procedures has contraindications that may interfere if you decide to undergo an examination.
do not prescribe:
- Pregnant women and women while breastfeeding
- Children at an early age
- In case of frequent procedure
- If there is a cast in the examination area
- With renal failure.
Magnetic resonance imaging also has its contraindications: - claustrophobia, schizophrenia
- The presence of a pacemaker, metal implants, clips on vessels, other metal objects in the patient's body
- Pregnancy in the 1st trimester
- Overweight patient (over 110 kg)
- Renal failure (when using contrast agents).
Be sure to consult a doctor before undergoing the study.
CT and MRI are used to diagnose and prescribe treatment for a huge number of diseases. You need to know that the purpose of a particular examination method depends on which part of the human body is to be examined.
Your doctor refers you to one of these studies, perhaps even after a CT scan you were sent to do an MRI? Which is better MRI or CT? MRI is significantly more expensive than CT, perhaps it is better, or is it too expensive for you and you can limit yourself to a simple CT?
Let's see what each procedure is individually.
Computed tomography (CT). This method is based on X-rays. The human body passes through the machine, where it takes a lot of layered pictures. They are processed by a powerful computer with the help of special programs. Thanks to this, the doctor can view the radiograph of the organ of interest in any projection, and even layer-by-layer sections.
Magnetic resonance imaging - this study is in many ways similar to CT: they also transport the human body through the apparatus, get the same sections.
But the principle of operation is different! Harmful x-rays are not used here, but only a magnetic field. In fact, the apparatus is a pipe in which a powerful electromagnet is hidden, which generates a pulsating magnetic field. Hydrogen atoms enter into resonance with the apparatus and send signals that are recorded by sensors.
What is the difference between CT and MTP and which is better
It is impossible to say unequivocally which is better than CT or MRI. Computed tomography is based on x-rays. These rays are blocked by dense tissues (such as bones) and pass freely through soft tissues and fluids. But here you can “cheat” a little by injecting the patient with an intravenous iodine-based contrast agent, which well delays x-rays. Different tissues accumulate contrast in different ways, and as the formation contrasts, one can judge its blood supply. Different X-ray permeability of tissues makes it possible to judge the density and structure of the object. Bones are best visualized on CT, if you are interested in them, then computed tomography will undoubtedly be the best choice.
Magnetic resonance therapy is based on signals received from hydrogen atoms, which are found most in water and fats. Such a study more clearly visualizes various soft tissue formations, makes it possible to judge their contours and boundaries, well shows the vessels, but provides little information about the density and structure of the tissue. MRI is best suited for examining soft tissues, recognizing the tumor process in the early stages, and helping to learn about the state of the body's vessels.
Which study is best for the brain
With computed tomography of the brain, the bones of the skull and pathological dense inclusions in the brain (for example, calcifications) are well visualized.
Head CT is more effective for:
On MRI, you can clearly see the structure of the brain, the outflow of cerebrospinal fluid and blood vessels. Brain MRI is indicated for:
- Suspicion of a tumor process in the brain - a soft pathological formation is clearly visible, it is possible to assess the clarity of its contours.
- Hemorrhage in the brain - blood is a liquid and it is clearly visible, you can assess the extent of the hemorrhage and determine the burst vessel.
- Diseases of the blood vessels, such as malformations, aneurysms, anomalies in the development of blood vessels, since the vessels are best seen on an MRI.
- Multiple sclerosis.
Which study is best for the spine
The spine is made up of the vertebrae, intervertebral discs, and spinal cord. CT is suitable for you if you want to examine the vertebrae in case of spinal injuries, vertebral fractures. In diseases when bone density changes: osteoporosis, osteochondrosis.
An MRI can help you deal with your back pain. The back can hurt if you have a protrusion or intervertebral hernia, or infringement of the roots of the spinal nerves (in this case, the limb can also hurt or go numb), a tumor that compresses the spinal cord. The spinal cord is examined for paralysis, which can occur with inflammatory diseases and trauma.
What to choose CT or MRI for the abdomen
For the abdominal cavity, both methods can be equally informative, for example, with stones in the bile ducts and gallbladder; for various kidney diseases. But CT is preferable for urolithiasis, since kidney stones are dense and absorb X-rays well and are clearly visible, but there is practically no water in them and they can not be seen at all on MRI. Various intra-abdominal bleeding (fresh blood is clearly visible on CT).
MRI is preferable for volumetric formations of the pancreas: cysts, abscesses, tumors, acute and chronic pancreatitis, portal hypertension, postoperative complications: interloop abscesses, adhesive disease, foreign body.
MRI is informative in examining the intestines for any tumors, the cause of obstruction. Also, MRI is necessary for the diagnosis of circulatory disorders in the vessels of the abdominal cavity, organ ischemia, aneurysm and aortic dissection.
What is better to choose for the liver CT or MRI
In the case of liver disease, MRI will be the most successful study. With it, you can clearly visualize neoplasms in the liver and their contours, whether it be an abscess, a cyst or cancer with metastases.
For parenchymal diseases, it helps to assess the size of the liver, the condition of the bile ducts. Find developing portal hypertension.
Also, CT is most informative in the case of diseases associated with the melting of bone tissue (osteoporosis, osteomyelitis), or the growth of bone tissue (osteochondrosis, defarthrosis). The defeat of bone structures by a tumor process. Traumatic damage to the skeleton. Diseases of the abdominal organs, lungs, pelvic organs, only with contrasting.
MRI is the best choice for neoplasms of adipose tissue, muscles, abdominal cavity and pelvic organs. Assessment of the state of the structures of the brain and spinal cord. Conditions of the blood vessels of the whole body. Examination of intervertebral discs and joints.
Contraindications for CT and MRI
You also need to know the contraindications to research that may incline to a different type of diagnosis.
Contraindications for CT:
- Pregnancy.
- Allergy to preparations containing iodine (used for contrast tomography).
Contraindications for MRI:
General contraindications
- Body weight over 150 kg.
- Motor excitation of the patient.
Preparation for procedures
For an MRI, no special preparations are needed, it is only necessary to remove all jewelry and put on clothes without metal elements.
For CT, the following preparations are required. The day before the study, it is necessary to exclude products that increase gas formation (flour products, juices). In the morning before the procedure, an enema is made to cleanse the intestines, and a tampon is inserted into the vagina for women. CT is started with a full bladder.
In both cases, if the patient is afraid to carry out the procedure and cannot lie quietly in the apparatus, he is offered to drink a sedative. For small children and infants, the procedure is carried out under anesthesia, the anesthesiologist watches the patient all the time.
You need to know that neither CT nor MRI can make a diagnosis in isolation, and you don’t need to do tomography just for the sake of “unusual pictures” of your body. The doctor directs all procedures only after a comprehensive examination, history taking, listening to your complaints. The attending physician, together with the radiologist, chooses the optimal tomography, whether it be CT or MRI. Now both methods are quite affordable, you can sign up for them directly from your computer on our website.
To do this, for your convenience, we offer the “order a call” service, and you can also dial our phone number yourself, which is indicated in the upper right corner of the site. Our consultants will help you with the choice of a clinic or a doctor, make an appointment for the date you need, and consult additionally on any questions you may have.
You can also choose a clinic in any major city in Russia, as well as find a doctor based on his rating, reviews, cost. To do this, you first need to select the scope of your disease.
The use of the latest techniques in body diagnostics makes it possible to detect various pathological changes in the functioning of human systems and organs at an early stage. Today it is difficult to imagine the development of medicine without non-invasive methods for diagnosing various kinds of diseases, namely, computed tomography and magnetic resonance imaging. But, faced with the choice of one or another diagnostic technique, it is important to know not only the main differences between MRI and CT, as well as their pros and cons, but it is also necessary to understand under what conditions their use will be appropriate.
Principles of operation and main differences between CT and MRI
For a simple understanding of the main differences between MRI and CT, you first need to understand how they work.
When examining parts of the body using MRI, the patient is affected by both pulsating constant magnetic fields and radio frequency radiation. They are formed by a special apparatus - a tomograph. In a matter of seconds, the device sends a radio frequency pulse to a certain area, which causes the hydrogen atoms in the cells of the body to sway and resonate. Further, special equipment collects the received signals, processes them and outputs a three-dimensional image with the chemical structure of the tissues in this area.
In the case of using the CT technique, the part of the patient being examined is exposed in layers to an X-ray beam, which is sent from a special apparatus. Due to the different density of the tissue, the rays are absorbed differently by them, which is fixed by special devices. They process the received data and then issue a layered image of tissue sections, that is, their physical state.
Which is better, MRI or CT?
Since the method of computed tomography is based on X-rays, the patient is exposed to direct radiation during the study, which is the main disadvantage of CT. New developments of designers made it possible to reduce the radiation dose to a minimum, but still the effect on the patient of radiation remained. This cannot be called a plus.
Unlike CT, when diagnosing the body using MRI, the patient is not affected by any radiation at all, which allows doctors to prescribe it even to pregnant women and children. This is the main difference between MRI and CT. Thanks to him, magnetic resonance imaging has become one of the safest methods for research. This is her absolute plus.
In all other respects, MRI differs from CT only in its scope. After reading the information on the site prokishechnik.ru, one can easily understand that MRI is more preferable for focal and diffuse lesions of various parts of the brain, pathologies of the craniospinal junction and spinal cord, as well as for lesions of human cartilage tissue. CT, in turn, is best in diagnosing diseases of the abdomen, chest, base of the skull, pelvis, in detecting tumors, bleeding, etc. Also on the site “about the intestines” the main pros and cons of magnetic and computed tomography are described in more detail, so that you can easily find out the answer to the eternal question “Which is better? MRI or CT?
MRI is more informative for
- Inflammation of the brain tissue, brain tumors, strokes, multiple sclerosis;
- Diseases of the spine and any lesions of the spinal cord;
- Muscular tissue and articular surfaces;
- Diagnosis of the contents of the pituitary gland, orbit and intracranial nerves;
- Cancer research at different stages;
CT is more informative for
- Diagnosis of circulatory disorders, brain tumors;
- Damage to the teeth, facial skeleton, thyroid and parathyroid glands, as well as jaws;
- Injuries to the bones of the skull, brain and intracranial hematomas;
- Damage to the temporal bones, paranasal sinuses and bones of the base of the skull;
- Diagnosis of otitis, sinusitis and pyramids of the temporal bones;
- For almost all pathologies in the abdomen;
- Atherosclerotic lesions of blood vessels and aneurysms;
- Research on tuberculosis, lung cancer, pneumonia and other chest pathologies;
- Diseases of the spine (herniated discs, osteoporosis, scoliosis, etc.);
- Observation of metal implants, damaged bones and their diseases.
That was a breakthrough in medicine. This made it possible to see internal disturbances in the human body, to find out the state of its organs. But even this excellent method carries some drawbacks. For example, an x-ray can take a picture of some organs, but images of other organs can also be superimposed on them.
And in this case, only an experienced and knowledgeable doctor will be able to decipher the result. Therefore, because of these shortcomings, progress has gone further.
New Methods
Nowadays, there are other ways to diagnose human internal organs, such as CT or MRI. But then a lot of questions arise from this. For example, what diagnostics to choose, what is the difference between CT and MRI? Further in the article we will describe in detail their differences. We will also explain which diagnostics are more suitable for a particular case.
Understanding the difference between CT and MRI
Now many doctors recommend that patients for better diagnosis conduct more thorough examinations, using computed or magnetic resonance imaging. What is this research? How is CT different from MRI? Let's take a closer look:
- CT scan is carried out using the property of X-ray radiation to be absorbed differently by different tissue thicknesses. That is, CT, in general, is identical to X-ray, but the information obtained with its help is processed in a completely different way, and the radiation exposure is much higher.
- produced using a magnetic field. Hydrogen atoms, due to its influence, change their place, and the tomograph captures this effect and processes it into a three-dimensional image.
As you can see, the question - what is the difference between CT and MRI, what is the difference between these two diagnostic devices - immediately receives an answer. The main difference is in the nature of the waves. Magnetic resonance imaging has electromagnetic waves. When they affect different tissues of the organs, due to this, various data are obtained, which are read using the apparatus device. And then all the signals are processed and, as in the CT examination, an image is given on the monitor. Thanks to him, the doctor has the opportunity to see even layer-by-layer sections of organs. In addition, the image can be rotated and, if necessary, enlarge the desired area.
What is the difference between CT and MRI? What tomography is better? Each diagnostic is good and informative. The main difference lies in what pathology can be detected thanks to these methods, and in addition, with the help of which rays this is done.
Scan time difference
Speaking about the difference between CT and MRI, it is worth noting that computed tomography (CT) has a serious radiation effect, and therefore it cannot be used often. But on the other hand, X-ray radiation affects the organs for no more than 10 seconds. So, such a study is best done with those people who suffer from claustrophobia.
Magnetic resonance imaging (MRI) usually lasts from ten minutes or more, depending on the study area. At the same time, you need to remain still. Therefore, MRI is more suitable for people who do not have any serious mental disorders. As for children, when using magnetic resonance imaging, they are given anesthesia.
Based on the foregoing, one can understand how MRI differs from CT. Which is better MRI or CT for you? Only a doctor can answer this question, based on the characteristics of your body.
When is MRI used?
Inexperienced people who suffer from various diseases, turning to their doctor, ask the question of how CT differs from MRI. But since we have already found the answer to it, then we will talk further about which diseases it is best to use MRI, and where - CT.
MRI provides the most complete information when studying soft tissues. Therefore, it is prescribed in cases:
- if a person has formations in muscle tissue, fat cells, in the abdomen and pelvis (this is done to obtain a complete picture after an ultrasound examination);
- with various diseases of the brain and spinal cord;
- when there is a suspicion that there are circulatory disorders in the region of the brain or spinal cord;
- when you need to examine the intervertebral discs or the condition of the tissues of the joint.
When is computed tomography used? She is appointed:
- to study bone tissue in the region of the spine and joints;
- when the bone tissue is affected by tumor formations;
- when the bones of the skeleton were injured;
- with pathologies in the organs of the abdominal cavity, small pelvis, as well as in the lungs;
- with atherosclerotic changes in the vascular system.
Contraindications
Based on what was described above, the doctor will be able to choose the right type of diagnosis for each patient individually. But there are some contraindications that should be taken into account.
These include the following:
- CT is not allowed during pregnancy.
- MRI is not prescribed:
- in the presence of any metal parts implanted in the body;
- with electronic devices present in the tissues (for example, a pacemaker);
- those suffering from claustrophobia;
- with a person weighing more than 150 kg;
- patients with neurological disorders who are not able to stay in one position for a long time.
A small conclusion
The question of which of the two examinations is better to choose is asked by each person who is to undergo internal diagnostics. And in order not to harm your health and get as much useful information as possible, the patient should definitely ask his doctor what is the difference between CT and MRI. And the specialist will help determine what is more suitable for the patient in each case.
The main difference between CT and MRI lies in the different physical phenomena that are used in the devices. In the case of CT, this is X-ray radiation, which gives an idea of physical state of matter, and with MRI - constant and pulsating magnetic fields, as well as radio frequency radiation, which provides information about the distribution of protons (hydrogen atoms), i.e. O chemical the structure of tissues.
In the case of CT, the doctor not only sees tissues, but can study their X-ray density, which changes with diseases; in the case of MRI, the doctor evaluates the images only visually. Quite often, an MRI or CT scan is prescribed by the attending physician, but, as a rule, it would be better if he did this after consulting with a radiation diagnostician: in a number of cases, instead of expensive MRI, you can use cheaper, but no less informative computed tomography.
In general, MRI is better at distinguishing soft tissues. In this case, the bones cannot be seen - there is no resonance from calcium, and the bone tissue on MRI scans is only indirectly visible. It can be stated that today MRI is more informative in diffuse and focal lesions of brain structures, pathology of the spinal cord and craniospinal junction (here CT is not at all informative), and damage to cartilage tissue. CT is preferred for diseases of the chest, abdomen, pelvis. base of the skull. In some cases, to establish the correct diagnosis, it is necessary to resort simultaneously to MRI and CT.
MRI more informative:
- Intolerance to a radiopaque agent when its administration is indicated on CT;
- brain tumor, brain tissue inflammation, stroke, multiple sclerosis;
- All lesions of the spinal cord, diseases of the spine, mainly in young and mature people;
- Orbital contents, pituitary gland, intracranial nerves;
- Articular surfaces, ligamentous apparatus, muscle tissue;
- Staging of cancer (with the introduction of a contrast agent, for example - Gadolinium).
- Acute intracranial hematomas, injuries of the brain and skull bones;
- Brain tumors, cerebrovascular accidents (MSCT);
- Damage to the bones of the base of the skull, paranasal sinuses, temporal bones;
- Damage to the facial skeleton, teeth, jaws, thyroid and parathyroid glands;
- Aneurysms and atherosclerotic lesions of vessels of any localization (MSCT);
- Sinusitis, otitis, damage to the pyramids of the temporal bones;
- Diseases of the spine, including osteoporosis, herniated discs, degenerative and dystrophic diseases of the spine, scoliosis, etc. Contrary to popular belief, computed tomography is much more informative for diagnosing lesions of the vertebrae and discs, however, attending physicians are not able to see changes on computed tomograms and recommend patients more visual for themselves MRI;
- It is preferred for lung cancer, tuberculosis, pneumonia and for clarifying chest radiographs that are difficult to interpret, with pathology of the chest and mediastinum;
- The most sensitive technique for recognizing interstitial changes in the lung tissue, fibrosis and for the search for peripheral lung cancer at the preclinical stage (MSCT);
- With almost the entire spectrum of pathological changes in the abdomen;
- Bone injuries and diseases, examination of patients with metal implants (joints, internal and external fixation devices, etc.);
- Preoperative MSCT with three-phase angiography makes it possible to obtain an optimal anatomical picture in the area of surgical intervention and to recognize most of the pathological processes in the organs of the abdomen and abdominal cavity.
- metal fragments;
- pregnancy;
- Artificial pacemaker;
- Hearing aid or implants in the cochlea;
- metal implants;
- Fixed metal dental bridges and/or crowns;
- Surgical clips, for example, in the area of an aneurysm;
- Surgical braces;
- Side pillar stimulators;
- Kava filters.