What can a CT scan of the brain show? Computed tomography in traumatic brain injury

Brief description of the procedure

Time spending: 5-15 minutes
The need for a contrast agent: as prescribed by the doctor
The need to prepare for the study: No
Presence of contraindications: Yes
Restrictions: available
Conclusion preparation time: up to 1 hour
Children: over 14 years old

What is a brain CT without contrast?

Computed tomography is an X-ray technique for studying the anatomical and functional states of organs and tissues without external interference in their integrity through step-by-step scanning. CT is based on the measurement and further processing by a computer of the difference in the attenuation of X-rays as they pass through tissues.

Unlike classical radiography, brain tomography allows you to get a three-dimensional image of this organ, and the minimum slice thickness during scanning (about 0.5-1.0 mm) makes it possible to obtain complete information about the processes occurring in the brain tissues.

As a result of layer-by-layer scanning of the brain, a series of images is obtained, which can be converted into a spatial model of the organ.

This type of study can be prescribed if the patient has the following symptoms:

ripples in the eyes, vomiting, nausea;

dizziness, loss of consciousness;

chronic or severe pain without any cause or after a head injury;

a sharp deterioration in vision, hearing, orientation, speech;

previous trauma of the skull, which is accompanied by fainting, vomiting, increased intracranial pressure, bleeding disorders or epileptic seizures;

for the first time or re-developed convulsive syndrome, in the second case also with symptoms of fever, persistent pain in the head, changes in mental state and accompanied by an oncological history.

What pathologies are detected by computed tomography of the head without contrast?

Computed tomography of the brain is successfully used to diagnose inflammatory, oncological processes, the consequences of injuries, the presence of foreign bodies in the brain, including metal ones. This method is an alternative to magnetic resonance imaging of the brain - in most cases, non-contrast CT is as informative as MRI. In addition, CT has several advantages: this technique is better suited for detecting fresh hemorrhages on the first day after the incident and the consequences of traumatic brain injuries, which appear on CT images after 6 hours.

Also, computed tomography of the brain can be prescribed to patients with absolute contraindications to MRI.

CT of the head without contrast enhancement has been successfully used to diagnose:

violations of the integrity of the bone tissue of the skull;

displacement of internal structures;

fresh bleeding associated with stroke and trauma;

enlargement of the ventricles of the brain with hydrocephalus and increased intracranial pressure;

anomalies in the development of the skull and brain;

encephalitis;

concussions, bruises, other head injuries;

meningitis;

brain abscesses.

The most common pathologies diagnosed by non-contrast CT

CT is one of the few techniques that can detect ischemic and hemorrhagic strokes at the earliest stages.

Ischemic stroke is an acute violation of the blood circulation of the brain with tissue damage and dysfunction due to difficulty or complete cessation of blood supply to any area of the brain. The most common cause is blockage of the artery by a detached plaque or thrombus.

The main symptoms are:

rare pulse;

weakness, dizziness;

sweating;

numbness in the limbs, often unilateral;

impaired hearing, vision, speech;

violation of the rhythm, depth of breathing;

facial asymmetry;

involuntary urination;

convulsions, partial or complete paralysis of the arms or legs.

Hemorrhagic stroke characterized by rupture of blood vessels and hemorrhage in the brain. This type of stroke usually develops within seconds and can lead to a poor prognosis.

The consequences of hemorrhagic stroke are similar to the consequences of ischemic stroke, but in a more severe form and their degree depends on the localization of the affected area of the brain.

The main consequences of the disease are partial or complete impairment of limb mobility, cerebral edema, pronunciation difficulties, behavioral disorders, perception disorders, loss of the ability to learn, think clearly, etc.

It is with the help of computed tomography that it is possible to distinguish ischemic stroke from hemorrhagic - in the case of the first type of stroke, zones of low density are determined on CT images - blackouts in the brain tissue, with hemorrhage, areas of increased density are visible on the images - white and light. Thus, CT allows timely diagnosis of acute pathology and making a decision on thrombolytic therapy in patients with ischemic stroke.

Also, non-contrast CT of the brain and skull bones can be recommended before surgery, during biopsy, to assess the extent of damage to bone and soft tissues in patients with facial trauma, to identify disorders of the temporal bones of the skull and paranasal sinuses.

Features of conducting and preparing for CT of the head

Computed tomography of the brain does not require special preparations - before the study, you do not need to refuse to drink, eat or take medications.

The procedure itself does not differ from other types of CT - the patient is placed on a movable table of the tomograph, which moves along the rotating ring of the apparatus.

Direct scanning takes only a few seconds, and the duration of the procedure, including paperwork, dressing the patient in special clothes, ranges from 10-15 minutes.

Computed tomography of the brain is a type of X-ray examination that has more opportunities. Namely, as a result of CT of the head, the specialist receives a series of layered images of the organ under study. Due to the detailed image, the tomogram shows even violations of the tissue structure. CT using vascular contrast is called angiography. This method is necessary for the diagnosis of pathologies of intracranial vessels.

Despite all its advantages, computed tomography is not informative in all cases, since it does not display the structures of soft tissues. For their study, it is preferable to conduct magnetic resonance imaging.

The essence of the method

Computed tomography is a type of X-ray examination that gives a three-dimensional and more detailed, detailed image.

This diagnostic technique is based on the use of x-rays. The X-rays generated by the X-ray tube of the tomograph are directed at different angles through the patient's body, as a result of which special sensors capture information about the layer-by-layer scanning of the object, and the computer, processing the data, builds a complete picture.

Compared with radiography, this type of study is much more informative, since it allows you to visualize the structure of an organ at different levels.

Computed tomography has no contraindications inherent in magnetic resonance imaging:

metal implants and prostheses;
artificial pacemaker.

In addition, this type of diagnostics differs from MRI in a shorter amount of time required for the procedure.

What is seen on the tomogram?

The image (tomogram) shows the same structures as in the X-ray image, but, thanks to additional features, such an image more fully displays the organ under study.

The result of computed tomography is a series of images that show in detail the layered structure of the brain.

If contrasting of the vascular bed is used during computed tomography, blood vessels are visualized (this method is called CT angiography). With the help of angiography, the doctor gets the opportunity to see the state of the cerebral vessels:

Arteriography: study of the features of cerebral arteries - their patency, uniformity of the lumen, the presence of parietal thrombi, atherosclerotic plaques, neoplasms, aneurysms and malformations. The method also helps to evaluate microcirculation.
Venography is necessary, if necessary, to assess the outflow of blood through the veins and venous sinuses.

Angiography allows assessing the usefulness of the blood supply to intracranial structures and diagnosing atrophy of the brain substance.

Diagnostic capabilities of the technique

Computed tomography of the head is a very informative research method and is used to diagnose a number of pathological conditions:

Traumatic brain injury. Visualization of the structure of bone tissue using computed tomography allows you to exclude or confirm the presence of fractures of the skull bones. And with the help of vascular contrasting, it shows traumatic intracranial hemorrhages. A tomogram will show and foreign bodies that have fallen inside the skull as a result of an injury.
intracranial hypertension. The examination helps to identify intracranial volumetric processes that are the causes of hypertension syndrome: intracranial hematoma, tumor process. Venography allows you to identify pathological changes that are the cause of impaired venous outflow.
Acute disorders of cerebral circulation. Computed tomography with vascular contrasting reveals the localization of arterial rupture in hemorrhagic stroke and the presence and size of the ischemic focus in cerebral infarction.
In early childhood, CT scans may be prescribed if a birth injury is suspected in a child or to clarify the causes of hydrocephalus.

How to find out the state of the human brain in less than half an hour? Perform computed tomography. The method was developed at the end of the last century. Today, it is prescribed, on average, to every second patient who suffers from severe headaches.

A CT scan of the brain is prescribed for adults and children from three years of age. A prerequisite for a tomography of the head is to be in a state of complete rest throughout the entire period of time while the brain is being scanned. That is why the minimum age of the patient is a relative concept: not all three-year-old children are able to lie quietly for five minutes. Restless babies are given light anesthesia, which immerses the child in a superficial sleep. Not all parents like this, but only computed tomography is able to assess the state of the tumor in dynamics.

It is worth signing up for a CT scan if you suffer from dizziness, the causes of which cannot be established by other methods.

Computed tomography of the head consists in a detailed scanning of this area with a special device. The method is based on X-ray radiation. It is able to penetrate the tissues and organs of the human body, forming a certain pattern on a large film.

The doctor evaluates:

film image;
the speed of passage of x-rays;
the body's response to such an intervention.

The last two points may seem strange: why does the doctor need to know how fast the beam scanned the tissue? The fact is that through a hematoma, a malignant tumor or a benign neoplasm, x-rays pass more slowly. If the body is healthy, then the beam propagates at a speed of up to 300 thousand kilometers per hour - this is the speed of light.

X-ray does not cause any injuries to the body and brain. It is important to understand that this is partly harmful radiation, but minimal exposure occurs during the study. Benefit - disproportionately higher than the possible harm.

The process is voluntary. No one will force a person to go to CT without his consent. For children and disabled citizens, their parents, guardians, legal representatives decide.

Indications and contraindications

Computed tomography of the vessels is prescribed in cases where the attending physician cannot determine the nature of the patient's pain or doubts the diagnosis.

A CT scan of the head and neck is mandatory for:

various injuries and damage to this area;
suspected tumors;
frequent headaches;
convulsions;
hallucinations;
sudden loss of vision;
ban on MRI;
various congenital pathologies;
accumulation of excess internal fluid.

Any problems related to the head and neck should be "passed" through a CT scan. The doctor on the spot will find out what to treat the patient for, whether he needs emergency care, whether he needs to be placed in a hospital for further observation.

If a person regularly has a headache, up to fainting and nausea, it is worth going to the clinic immediately: in the presence of any of these symptoms, a CT scan of the brain is required.

The doctor must inquire whether the citizen agrees to the examination, whether he has doubts, contraindications. It is also best for the patient to find out all the information of interest right in the doctor's office.

It is impossible to postpone the diagnosis for longer than a month, because during this time the tumor can increase two to three times.

Preparation and holding

To do a CT scan of the brain, no special preparation is required. The patient does not need to starve, take medications, or tune in morally. In the process, he will not experience pain, tension, tingling, vibration.

Preparing a patient for a CT scan of the brain includes full information about all the details of the procedure.

Sometimes it is recommended to drink a mild herbal sedative before a CT scan of the brain, it is better to check with the doctor. Taking a sedative half an hour before the procedure will remove excitement and nervousness. Then the results will be more accurate. In one out of three patients who experience severe stress before the study, the results are inaccurate.

In most cases, brain tomography does not require the introduction of a special substance into the blood. It is prescribed if you need to consider small blood vessels inside the skull.

The agent injected into the blood contains iodine, therefore, when it enters the bloodstream, a metallic taste occurs in the mouth. This is a completely normal phenomenon that disappears after 30-60 minutes.

It is forbidden to introduce contrast when:

damage to brain structures;
if the patient is diagnosed with Alzheimer's disease.

How is the procedure

The procedure for examining the brain using CT is no different from carrying out similar manipulations in other parts of the body. The detailed algorithm is presented below:

for a tomography of the head of a citizen, they are invited to a separate room;
ask questions about contraindications;
are asked to remove all metal jewelry;
the patient is laid down on the couch;
the head is fixed with holding devices so that the subject does not have the opportunity to move it, distorting the CT results;
the couch together with the patient is rolled up inside the tomography apparatus, where the analysis takes place;
after it is over, the couch leaves, the person is released and asked to wait outside until the results are deciphered.

How long does a brain CT scan take? Research speed is affected by:

human behavior;
technical characteristics of the CT apparatus;
the scope of the study.

On average, the procedure lasts from 15 to 35 minutes.

Using contrast

In some cases, computed tomography with contrast is prescribed for the study of the brain. In nine cases out of ten, CT scan of the head and blood vessels with contrast makes it possible to identify vascular pathologies inside the skull from the first time.

Contrast-enhanced CT is not performed in children before adolescence to rule out an unusual reaction to a substance. The effect of enhancer drugs on the child's body has not been fully studied.

If a CT scan of the head and neck with contrast enhancement is planned, the doctor talks about this before the study, and not in the process or directly at the door of the office.

What does a CT scan of the brain show without contrast? Any tumors, injuries, hematomas, but does not visualize small vessels, including clogged ones.

In half of the cases, tomography with contrast is used to analyze the pelvic organs; cerebrovascular accidents are successfully diagnosed.

The contrast agent is absolutely harmless to the human body if there is no allergy to it. However, two prohibitions are still present: its introduction is prohibited for children and pregnant women.

What does a CT scan of the brain show?

It can be argued that brain tomography helps to identify all diseases associated with the region of the cranium, with the exception of mental illnesses.

CT is excellent for detecting brain tumors.
Scanning instantly determines the cyst: its presence and location down to the millimeter.
Brain tomography will not show mental illnesses and disorders, since it studies not the functional, but the physical properties of the object under study.

CT angiography of cerebral vessels

Suspicion of the presence of blood clots or head trauma is an unconditional indication for a CT scan of the cerebral vessels. In most cases, contrast is required to make an accurate diagnosis.

You should not be afraid of CT diagnostics of the vessels of the brain and neck - pain is completely excluded. But CT angiography of the vessels will determine the condition of the arteries, veins inside the brain and whether the “gray matter” of the patient is normally supplied with blood.

The doctor prescribes a CT scan of the brain with angiography for children and adults, if the situation requires it: pathologies or malfunctions of the arteries and veins.

The direction for the study is issued by the supervising doctor, and the conclusion is issued by the radiologist. To scan the cranial cavity, the specialist must have:

higher professional education;
license for this type of activity.

Advantages of the method

Modern computed tomography of the brain has the following advantages over other studies:

allowed for people with pacemakers;
passes quickly (within 15-30 minutes);
the procedure is painless;
assigned to children from 3 years;
no special training required;
decoding of the results takes place within an hour (sometimes longer if the case is severe).

Possible risks

Any medical procedure is associated with the risk that the body of a particular patient will show a non-standard reaction. Therefore, allergies, pregnancy, kidney failure, psychological illnesses must be reported to the doctor before a brain tomography is performed.

In the normal course of the study, the effects of CT on the brain are absent.

Is a CT scan of the brain harmful? No, if it is carried out in accordance with the instructions.

Deciphering the results

The results are not provided to the patient immediately after the procedure, but after a while - within 30-60 minutes.

If the CT scan of the brain reveals a norm, then the results will probably be reported immediately.

In private and public clinics, a conclusion on a CT scan of the brain is issued along with a picture in the hands of a person or left in a personal card.

CT scans of the brain should not be exposed to moisture, high temperatures, or direct sunlight.

Price

In private clinics, brain tomography is a paid procedure. It costs from 2 to 5 thousand rubles. It depends on the pricing policy of the medical institution.

In the state polyclinic, computed tomography of tissues and vessels of the brain is not always carried out, as not all medical institutions are equipped with special equipment.

A computer study of the brain allows you to find all pathologies in a short time and establish the exact cause of pain in this area.

Alternatives

Today, computed tomography of the head does not have a 100% alternative. Of all the types of research, perhaps only such a type as MRI can be compared with it. Second on the list is SPECT (single photon emission computed tomography) of the brain.

MSCT

A special place among the types of CT is occupied by spiral computed tomography of tissues and blood vessels of the brain, which is performed according to the same scheme as conventional CT.

What does MSCT of the brain show? With MSCT, unlike traditional CT, X-rays are directed at different angles, which increases the information content of the results and reduces the duration of the procedure. MSCT is indispensable in the diagnosis of strokes. It lasts 5-15 minutes and produces ultra-thin sections.

It is prescribed only for adults, not for children, pregnant and lactating mothers.

PET CT of the brain

Another type of CT scan is positron emission tomography. Its peculiarity lies in the fact that the doctor gets the opportunity to follow the metabolic changes in the tissues inside the head. This has become real only thanks to the technology of PET CT of the brain.

The cost of verification varies from 10 to 40 thousand rubles. It is prescribed in exceptional cases when it is impossible to determine the nature of pain in the head using conventional tomography.

Conclusion

Computed tomography is prescribed for adults and children from the age of three. Not recommended for pregnant and lactating mothers, people suffering from kidney disease. The procedure is painless and safe for the body. Can be done with or without contrast. Prices depend on the type and scope of the study, as well as the region.

CT of the brain is a fairly common examination in diagnostics and is prescribed to study the structures of soft tissues, detect tumors and anomalies, identify inflammatory processes, disorders and damage after injuries. CT of the head has a wide range of indications, since this type of examination in diagnostics is characterized by high accuracy and information content. In case of contraindications for CT, MRI or ultrasound will be an alternative.

What does a CT scan of the head show? Head CT scan is indicated for the following indications:

concussion, swelling, hemorrhage and other consequences of traumatic brain injury;
suspicion of circulatory disorders (stroke);
abscesses, cysts (you can establish the nature of the cysts);
inflammatory processes;
infectious processes (meningitis, encephalitis, encephalopathy);
to detect tumors, benign and malignant neoplasms, metastases (both CT and SCT can be prescribed);
anomalies in the development of structures and the vascular system of the brain;
aneurysm, thrombosis;
hydrocephalus (excessive accumulation of cerebrospinal fluid in the tissues);
convulsions, blurred vision, confusion, dizziness, decreased sensitivity;
research before carrying out operations, postoperative control;
to find out the causes of persistent headaches of an unexplained nature for two or three months;
inability to undergo an MRI (presence of a pacemaker, insulin pump, metal objects in the body).

CT allows you to assess the state and functioning of the brain, to identify the pathological process at any stage of its development. CT shows and provides data on the eyes, facial skeleton, inner ear, air cavities (sinuses) located in the paranasal bones.

CT angiography of the brain

This is a study of blood vessels in the cranial cavity. With a special syringe, a contrast agent is injected into the cubital or subclavian vein, which helps to “color” the vessels in such a way that they appear more clearly and clearly during the scan. In some cases, contrast is injected directly into the arteries.

CT pituitary

A CT scan of the pituitary gland is sent for examination of bones and cavity formations, and. Since it consists of a continuous soft tissue, it is sent for MRI for its study. prescribed in cases of contraindications for MRI. But the results in this case may not always be complete.

CT, as the primary method, is used in those rare cases when symptoms were preceded by severe traumatic brain injury with possible damage to the bones of the inner surface of the skull.

Spiral computed tomography of the brain (SCT)

Today it is the most advanced method of X-ray examination. During the scan, not only the table with the patient moves, but also the X-ray tube with the detectors in it rotates in a spiral. This method allows specialists to obtain more accurate high-quality images, and the examination and exposure time is much less. There are no interferences on the CT scans, which are created by the blood flow in the vessels. SCT does not require patient preparation. These modern types of diagnostics - CT, SCT and MSCT - allow specialists to obtain data that is not available using other types of research. And the latest multispiral devices (MSCT) have made it possible to further reduce the scanning time and increase the number of issued sections.

The principle of operation of CT

CT scan of the brain: photo

The principle of the CT scanner is based on the use of X-rays, but the emitter is different from the X-ray machine. In a CT scanner, a special tube rotates around the patient's body or is stationary at a certain angle to it and creates a conical beam of rays.

The radiation intensity in the tomograph is much less, so the body does not receive residual radiation. The receiving detector of the tomograph receives the rays that have passed through the patient's body. The data obtained during the scan enters the computer, which processes them using special programs. Almost the same programs are used in MRI. In terms of information content, not very much. Both methods of tomography provide data in the form of images, you can get three-dimensional images, highlight certain areas at any depth of the organ. But MRI uses a magnetic field that does not affect tissue, but atomic hydrogen and does not affect the general condition or functioning.

Preparation and conduct of the procedure

There are no specific requirements for the preparation of computed tomography of the brain. It is recommended to refrain from eating and drinking two hours before the examination. For the procedure, you can not take things made of metal, including jewelry, watches, credit cards, wear clothes with metal inserts. If there are implants, then it is required to notify the specialists performing the procedure.

How is a CT scan of the brain done? The examination procedure itself is not complicated. The patient is placed on a movable table, the head is fixed with straps. The table, together with the patient, smoothly moves through the tube of the tomograph apparatus, and the scanner rotates along the human body. During the scan, the patient hears noise and clicks. During the entire time of the examination, you can’t move, you need to lie completely still. Usually, the study is carried out by an X-ray technician, and the radiologist deciphers the pictures and writes the conclusion. Other physicians may be involved. Before the examination, you must remove all jewelry, watches, remove phones and cards, hearing aids. Clothing should be loose and comfortable. During the examination, the patient is alone in the office, and the specialist can talk with him via a two-way communication device. When a contrast examination is performed, a special contrast agent is injected into the vein. The conclusion and pictures can be obtained approximately one hour after the study.

The procedure does not cause pain in the patient, but it can be difficult for some patients to lie still throughout the procedure. Sedatives may be given to calm the patient. With the introduction of contrast agents, the patient may feel warm, as well as a metallic taste in the mouth. Some may feel a headache or stomach pain. All these symptoms should be reported to medical specialists. Head CT is performed very quickly - from 3 minutes, and if contrast is used, then in 15 minutes. Most of the time is spent preparing for the examination. This procedure has a very small number of restrictions to its appointment, and the results can be obtained on the day of its passage.

Contraindications for computed tomography of the brain

As a rule, the limitations are the same for CT of all areas and organs of the human body, including the brain. The only unconditional prohibition for undergoing CT diagnostics is pregnancy in women. Overweight people over 120 kg will not be able to be examined due to the parameters of the device. CT with contrast is contraindicated in nursing mothers, people with kidney and liver diseases, in the presence of diabetes, with an allergy to iodine. Nursing mothers in the case of the procedure, it is not recommended to feed the baby for 1-2 days.

How often can a CT scan of the brain be done? Although this type of tomography is widely used due to its information content and accuracy, it has a radiation load on the body. Therefore, there are certain risks of negative consequences for human health.

The issue of additional CT scans is decided only by doctors, taking into account all medical indications and previous examinations.

Exceptions may be situations when it comes to saving the patient's life and the risk weighs much less than the vital information received. Such indications can be strokes, heart pathologies, rupture of an aneurysm of a vessel, oncology, traumatic brain injuries and damage to internal organs. Therefore, the examination is also prescribed in cases where the average annual exposure rate is exceeded.

Often, the examination is prescribed again and after surgery to monitor the recovery process. In oncology, additional CT procedures are prescribed to monitor the occurrence of tumor recurrences. It should be noted that in medicine there are opportunities to reduce radiation exposure to the body without deteriorating the quality of images: multislice tomography makes it possible to greatly reduce the dose of such radiation and allows the procedure to be performed on children from 7 years of age.
CT scan of the child's brain. not possible without special reason. Still, although the minimum, but the dose of radiation a person receives. With several procedures, the dose exceeds the permissible norm and the child may be at risk for the development of tumor formations. Therefore, in order to prevent harm to the child's body, such a procedure is performed only as prescribed by doctors. For newborns and children under 1 year old, it is better to do a safer procedure - neurosonography. Of course, the benefits of CT scans far outweigh the risks of radiation exposure, and parents also need to be assured by doctors of the safety of tomography.

The advantage of CT for children will be the painlessness of the procedure: the baby is not exposed to the effects associated with damage to the skin (injection, biopsy, surgery). In addition, CT allows you to identify tumor formations, study the state of blood vessels, and also find pathologies that are not visible to other types of examination (for example, radiography).

Head CT with contrast

A simple CT in some cases does not give a complete picture of all brain structures. Therefore, in order to better visualize the examined patient, a contrast agent is injected, which is aimed at enhancing visibility, and highlights certain areas in the brain (where there is an inflammatory process or areas subject to degenerative changes).

CT with contrast of the brain is painless for the patient: the contrast will be taken orally as a conventional medicine or administered intravenously. There are different types of such drugs that individually serve specific diagnostic purposes.

CT with contrast of the brain is prescribed in the following cases:

for a more detailed study of the vascular system
to detect malignant tumors
for the study of neurodegenerative processes (Alzheimer's and Parkinson's diseases)
with brain damage by neuroinfections.

This examination using contrast has a number of its contraindications:

kidney failure
patients with diabetes before the examination will need to stop taking sugar-lowering drugs
the presence of an allergy to contrast agents - it can become an obstacle to undergoing a tomography
lactating mothers will need to stop feeding the baby within 2 days after the examination, and express breast milk.

Also, relative restrictions can serve as: problems with the thyroid gland, leukemia and multiple myeloma, iodine intolerance. Basically, all contrast agents contain iodine. Therefore, if the patient has an allergy to iodine, then this may lead to a refusal to be examined.
Thanks to contrasting, which makes all changes visible and distinguishable, doctors have the opportunity to obtain visualization and assessment of the state of brain structures at the physiological level.

Difference between CT and MRI of the brain

What is the difference between CT and MRI of the brain and which procedure to refer the patient to, is decided by specialists based on medical indications? MRI is indispensable for examining soft tissues or, and for examining bone tissue, sinuses and eye orbits, you need to undergo a CT scan. But no one will give an unambiguous answer about which method is better. In terms of duration, a CT procedure without contrast is faster, with contrast it is the same. In terms of general informativeness, the methods are approximately the same.

Contraindications for each method of examination will also serve as a reason for choosing between them. The requirement for an MRI appointment for a patient will be the absence of metal-containing implants, pacemakers, and insulin pumps in the patient's body. CT is prohibited for pregnant women, diabetics, and patients who underwent radiography shortly before CT. CT scans, for example, are best done for people who are claustrophobic, mentally ill, or seriously ill.

The head CT scanner was first used in 1971. Already in 1979, the developers of the technology received the Nobel Prize in Physiology or Medicine. Now a modern CT device seems to be a complex software and hardware complex. Computed tomography has varieties: spiral CT, multilayer CT, tomography with two radiation sources, with contrast enhancement.

What is computed tomography of the brain - this is a non-invasive medical diagnostic method by which an organ is examined in its layered sections. CT is based on the phenomenon of x-rays. The method can be seen as a digital evolution of radiography.

A beam of x-rays is directed to the organ. But due to the fact that the tissues have a density, these rays are weakened, and some do not pass at all. That is, computed tomography “sees through” thin areas, and does not shine through dense ones. Sensitive detectors are used to register X-rays. On the monitor, after digital processing, doctors receive a layered three-dimensional image of the brain, where you can see the pathological foci: tumors, injuries, cysts, abscesses, hemorrhage.

Existing CT indications:

Chronic fatigue, apathy, irritability, emotional instability, sleep disturbance, decreased concentration, memory impairment and slow thinking.
Periodic and chronic headaches. Loss of consciousness, nausea, vomiting. Headaches that are not relieved by painkillers. Acute headache, like a blow to the head, is a direct indication for CT in stroke.
A complex of autonomic disorders: constipation, diarrhea, feelings of lack of air, palpitations, sweating, dizziness, tremors in the limbs, cold hands and fingers.
Traumatic brain injuries: contusion, broken bones, concussion, penetrating trauma
New onset seizures, persistent changes in mental status, history of tumors or seizures.
Chronic alcoholism, drug addiction.
Neurological focal symptoms with loss of neurological function, for example, loss of visual fields, sudden lack of speech, different pupil sizes.

A CT scan is indicated not only in the presence of symptoms, but also as a planned diagnostic and preventive measure for a specific contingent, for example, people working with radiation. Also, a CT examination is prescribed in order to monitor the dynamics and effectiveness of treatment, for example, chemotherapy.

Computed tomography is also used when it is necessary to control the course of a medical or diagnostic operation. For example, a brain biopsy (lifetime tissue sampling) is performed under computed tomography visualization: it is necessary to control and look out for the passage of a puncture needle through the brain.

Computed tomography uses X-rays, and therefore is associated with little harm to the body. Therefore, there are absolute contraindications CT scan (when research cannot be done under any circumstances):

Pregnancy.
Excessive body weight of the patient, due to which he does not fit into the scanning device.

For more detail, contrast is used. It helps to illuminate the vessels of the brain. However, a contrast agent is a pharmacological preparation, for the use of which there are contraindications:

Renal and liver failure.
Having a history of allergies.
Exacerbation or decompensation of diabetes mellitus.
Decompensated heart failure.
Pregnancy.
Unsatisfactory condition of the subject (feeling unwell).
Thyroid disease

The possibility of performing CT with metal crowns is decided by the diagnostician. The presence of foreign bodies of such a structure is fraught with danger: during the study, the crowns can heat up, which can lead to burns or just discomfort. Therefore, always inform your doctor about the presence of metal crowns. However, metal inserts are not a contraindication to the study. When performing a procedure with metal inserts, the output image is distorted: the alloy can reflect the rays. Visualization will turn out to be inaccurate and uninformative.

How is the procedure

Preparation for computed tomography is not required. Before the examination, it is recommended to wear clothes that fit and take off easily and leave metal objects at home - they will be asked to remove them before the procedure.

How is a computed tomography of the brain done in steps:

You will register at the reception.
Enter the CT scanner room. You will be asked to take off your clothes and put on a bathrobe.
You lie back on the table. If they do a CT scan with contrast, they will give you a drug intravenously. They will explain to you that after the administration of the drug, you may experience a feeling of burning, warmth or tingling in the body.
The laboratory assistant will explain what will happen next and what you may feel. He will also say that if something happens, he will hear and see you.
Actually conducting CT: the table moves under the gantry (a rotating mechanism with sensors). The scan starts. During this time, the machine makes a quiet operation noise. When CT is done, you should lie still. You can only move at the command of a laboratory assistant or a doctor.
The last stage: the table moves to its original position. The contrast needle is removed. Get up, get dressed and get out. The entire study takes up to 30 minutes.

CT scans for children are done with anesthesia if the child:

Has not reached the age of 1 year.
He is afraid and does not tolerate closed space.
Shows fear when losing sight of parents.
Has mental disorders and a tendency to convulsive seizures.

Also, CT is done to the child with the parents. They wear X-ray shielded aprons and lie down with their children. Preparation for CT for children is not required.

How often can a CT scan of the brain be done: the procedure should not be performed more than 3 times a year. The intervals between the study should be 5 weeks. Ideally, tomography should be performed once a year: a single procedure is not harmful to the body.

Computed tomography can take place in two ways: with the introduction of a contrast agent and without it. The option without the introduction of an amplifying agent is a classic digital form of radiography. What does a CT scan of the brain without contrast show:

foreign bodies;
consequences of injuries;
volumetric intracranial processes (tumors, cysts, accumulation of blood);
inflammatory diseases;
displacement of brain structures - dislocation syndrome;
mechanical damage to the skull.

With contrast

CT with brain contrast is mainly used in the diagnosis of vascular pathologies. A contrast agent is a special pharmacological preparation that allows you to visualize those parts of the brain that are “transparent” and not visible to X-rays. The contrast agent in the vessels is able to delay radiation, and therefore improves visualization - answering the question what is the difference with and without contrast.

CT of cerebral vessels with contrast uses water-soluble structures containing iodine. They are injected into a vein, with the blood flow they spread through the circulatory system, enhancing the contrast of the vessels. The substance is naturally excreted through the renal system in the urine. To speed up the excretion of the drug, it is recommended to drink plenty of mineral water.

Examination of cerebral vessels with contrast begins with two options:

Manual administration of the drug. It is administered by a nurse or laboratory assistant. The drug is administered by injection: the rate of supply of the active substance is not regulated. The study begins after the contrast has spread through the circulatory system. This type is rarely used and is considered obsolete.
Bolus injection. The substance is injected automatically using an injector syringe. In this way, the rate of contrast injection can be adjusted. The method is mainly used in multislice computed tomography.

CT angiography is the main field of application of the contrast variant of the study. Angiography provides a three-dimensional image of the arteries and veins. In the course of the study, 3D computer modeling and reconstruction technologies are used.

CT angiography requires special training. For example, before the study, the patient's allergic history is studied: the contrast agent is foreign to the body, and it may not respond correctly. Angiography for children and adults is performed in the same way as conventional computed tomography.

With the help of angiography, the following pathologies can be detected:

Blockage of blood vessels by a thrombus.
Dissection of the arteries.
Aneurysm of the arteries, when a portion of the vessel protrudes, a pocket is created, which disrupts local blood flow.
Atherosclerosis of cerebral vessels.

A common side effect is the release of the contrast agent outside the vascular walls into the soft tissues. Because of this, the skin and subcutaneous tissue are damaged.

PKT

CT perfusion is the "gold" standard in the diagnosis of acute cerebrovascular accident. Doctors prescribe perfusion computed tomography to assess the passage of blood through the brain tissues. PCT can be considered as an adjunct to CT angiography. The essence of the method lies in the quantitative measurement of blood flow by assessing the change in X-ray tissue density during the passage of an intravenously administered contrast agent.

The preparation and procedure is the same as for standard contrast computed tomography. With the help of PCT, it is possible to study the state of the medulla and its blood flow in the shortest possible time. The method has no contraindications and can be performed in the patient's condition of any severity.

Perfusion computed tomography in the diagnosis of vascular accidents has the following advantages:

Areas of damage to the blood circulation of the brain are detected almost immediately after the first neurological symptoms of a stroke, which allows you to quickly determine the therapeutic tactics.
The ability to assess the reversibility of organic and functional disorders.
Evaluation of individual characteristics of blood flow in patients.
The possibility of evaluating the effectiveness of thrombolytic therapy.

In addition to studying vascular disorders, perfusion computed tomography is used in the diagnosis of intracranial formations. The technique allows to study the blood flow in tumors, which can noticeably well accumulate a contrast agent. PCT allows to determine the features of tumor hemodynamics, which in turn reveals the nature and histological form of the tumor. This helps to determine the tactics of treatment and the choice of chemotherapy drugs. Knowledge of the blood supply to the tumor and its internal blood flow allows doctors to plan the operation and successfully remove the pathological neoplasm.

Is it bad to do

Is CT harmful to health: computed tomography is a radiation exposure. The annual allowable dose of radiation exposure per year is 150 mSv. If you get a dose less - the body is not damaged, if more - the likelihood of mutations and the development of radiation sickness increases. One study of the brain on computed tomography is equal to 2 mSv. That is, the harm of CT for the body from radiation exposure tends to zero, since this value is far from reaching 150 mSv.

Is contrast-enhanced computed tomography harmful? Pharmaceutical preparations consist of chemical compounds that, when administered, the body can respond with an allergic reaction. They are of 3 types:

Minor side effects. They develop in 5 out of 100 patients. This is dizziness, nausea, sometimes vomiting, headache, burning sensation, hot flashes, pain at the injection site. These side effects are normal and go away on their own.
Moderate side effects. Basically, these are massive swelling of the face, difficulty breathing, lack of air. This condition needs emergency care.
Severe side effects. This includes cardiovascular insufficiency, fainting. This happens more often in people who have a history of allergies to other substances. This is where resuscitation comes into play.

To prevent side effects, allergic tests are usually performed: a light wound is made to the subject, where small doses of the allergen are applied, after which this area is studied - how the skin reacted. Also, to reduce reactions, antihistamines with anti-allergic effects are administered before the procedure. Is it harmful to do a CT scan - the CT scan itself is harmless, but contrast agents can cause damage.

Possible results

A study on computed tomography gives black and white layered images of the organ. A CT scan of the brain is obtained in three projections: frontal, axial and sagittal. The picture shows the brain and its vessels. The doctor studies the spatial arrangement of all structures relative to each other and the presence of pathological foci.

Deciphering CT is a comparison of the norm and pathology. The diagnostician evaluates the contours of the brain, light and dark areas, pathological shadows, foreign bodies. The presence of neoplasms is assessed by indirect and reliable signs. For example, a reliable sign is a displacement of brain structures. Hypodense foci of the brain on CT is an indirect sign of a tumor.

In general, the following phenomena are studied in the picture:

Changes in the structures of the brain.
The presence of neoplasms.
Integrity of the bones of the skull.
Inflammation, swelling of the brain, accumulation of fluid, the presence of cysts.
Changes to the Turkish saddle.
Bridge education.
Pneumatization of the paranasal and frontal sinuses.
Localization of the interhemispheric fissure.
Cortical grooves on the surface of the cerebellum and cerebral hemispheres.
The size and symmetry of the ventricles of the brain.