Lesions in the brain on MRI

Toxoplasmosis on MRI of the brain Magnetic resonance imaging is a painless and informative way to study the brain. Layer-by-layer MR scanning allows you to examine in detail all parts of the organ and evaluate their structure. Using certain sequences, it is possible to study in detail the white and gray matter, blood vessels, and ventricular system.

MRI is considered an effective method for identifying focal brain lesions. These include limited areas with a disturbed structure inside the substance of the organ. Such changes are often accompanied by mass effect, swelling, and deformation of the surrounding areas. Lesions in the brain on MRI appear as areas of change in the MR signal. Based on specific features, location, size and degree of influence on surrounding structures, the radiologist can make assumptions about the nature of the pathology. Using the information listed, the doctor makes a diagnosis, makes a prognosis for the patient and selects treatment.

What does a sinus x-ray show?

An x-ray shows the human skull with bone structures, cavities and septa. The method is used at the preparatory stage in surgery.

What can be seen on a sinus x-ray:

Foreign object in the nasal passages.
Inflammatory process, thickening of the mucous membrane of the infected area.
Consequences of injuries to the face and head.
The presence of exudate (mucous, blood, purulent) in the paranasal and frontal cavities.
"Airiness" of the sinuses.
Neoplasms: polyps, tumors, cysts.
Anomalies in the structure of the facial skeleton.

X-rays help to correct the diagnosis in case of fever or headache of unknown etiology.

Briefly about sinusitis

Sinusitis is inflammation of the mucous membrane in the maxillary sinuses. Nathaniel Gaymore was the first to describe these sinuses: the name came from his name. And Leonardo da Vinci was the first to draw the maxillary sinuses.

Essentially, sinusitis is sinusitis caused by various reasons, which are associated with infection in the sinuses and the accumulation of pus in them. It can be rhinogenic, odontogenic, traumatic, allergic.

Rhinogenic occurs due to untreated rhinitis, when the infection penetrates from the nasal cavity into the sinuses. Odontogenic sinusitis develops as a result of infection through a diseased tooth and inflamed tissue around it.

Traumatic rhinitis is a consequence of damage to the nasal septum, maxillary sinus or jaw.

Finally, allergic rhinitis occurs due to allergies to pollen, animal dander, dust mites, medications and other allergens.

Acute sinusitis lasts less than 3 months, recurrent acute sinusitis occurs up to 4 times a year, chronic sinusitis lasts from 3 months or more. An exacerbation of chronic sinusitis is also possible, when new symptoms are added to existing ones.

How is a sinus x-ray performed?

The procedure is not painful and does not require preparation. Receive a referral at an appointment with an otolaryngologist, infectious disease specialist or surgeon.

How to do a sinus x-ray:

The patient removes metal jewelry, glasses, and dentures.
To protect against radiation, he wears a lead apron or vest with a collar.
The laboratory assistant indicates how to position yourself correctly relative to the apparatus. Depending on the required projections, the position is changed at the command of a specialist.
While taking the photo, you should not move and hold your breath.
After development and decoding, the film with the description is given to the patient.

The conclusion is not considered a final diagnosis, but provides clarifying information for the treating specialist.

What do white and black spots mean on MRI images?

Zones of altered MR signal may indicate:

tissue ischemia;
edema;
necrosis;
purulent melting;
tumor transformation;
metastatic lesion;
gliosis;
demyelination;
degeneration, etc.

The radiologist describes the signal intensity, size and location of the lesion. Taking into account the information received, the patient’s complaints and data from previous examinations, the specialist can assume the nature of the pathological changes.

Acute disseminated encephalomyelitis on MRI

Darkening of the sinuses on x-ray

The method is based on the different permeability of hard and soft tissues by electromagnetic waves. Bones block radiation and appear white in the picture. Specialists are interested in blackouts, which determine the nature of the disorder.

Darkening of the sinuses on an x-ray indicates fluid accumulation. This is a sign of inflammation with the release of mucous or purulent secretion. Sometimes, the picture shows thickening of the walls of the mucous membrane lining the sinuses.

New growths stand out as clear dark spots with shadows. Polyps look like peas on a “pedicle”, and cysts have a cavity filled with fluid inside.

Types of lesions on MRI of the head

The color of the resulting image of normal brain structures and pathological changes depends on the program used. When scanning in angio mode, including using contrast, a branched network of arteries and veins appears on the images. Focal changes are of several types; based on their characteristics, the doctor can guess the nature of the foci.

With pathology of the medulla, the properties of the affected foci are disrupted, which is manifested by a sharp change in the MR signal compared to healthy areas. The use of certain sequences (diffusion-weighted, FLAIR, etc.) or contrast allows for more clear visualization of local changes. That is, if a radiologist sees a single lesion on the MRI results, different scanning modes or contrast will be used to study it in more detail.

When comparing changes with healthy areas of the brain, hyper-, hypo- and isointense zones are identified (bright, dark, and the same color as adjacent structures, respectively).

Brain abscess on MRI (indicated by arrow)

Hyperintense lesions

Identification of hyperintense, i.e. foci that clearly stand out on MR scans makes the specialist suspect a brain tumor, including of metastatic origin, hematoma (at a certain moment from the onset of hemorrhage), ischemia, edema, vascular pathologies (cavernomas, arteriovenous malformations, etc.), abscesses , metabolic disorders, etc.

Brain tumor on MRI (indicated by arrow)

Subcortical lesions

Damage to the white matter of the brain is usually characterized as changes in subcortical structures. Subcortical lesions identified by MRI indicate that the damage is localized just under the cortex. If multiple juxtacortical lesions are detected, it makes sense to suspect a demyelinating process (eg, multiple sclerosis). With this pathology, destructive changes occur in various areas of the white matter, including directly under the cerebral cortex. Periventricular and lacunar lesions are usually detected during ischemic processes.

Foci of gliosis

When brain tissue is damaged, compensatory mechanisms are activated. Destroyed cells are replaced by glial structures. The latter ensures the transmission of nerve impulses and is involved in metabolic processes. Due to the structures described, the brain recovers from injuries.

Identification of glial foci indicates previous destruction of the cerebral substance due to:

birth trauma;
hypoxic processes;
hereditary pathologies;
hypertension;
epilepsy;
encephalitis;
intoxication of the body;
sclerotic changes, etc.

By the number and size of altered areas, one can judge the extent of brain damage. Dynamic observation allows you to assess the rate of progression of the pathology. However, by studying the zones of gliosis, it is impossible to accurately determine the cause of the destruction of nerve cells.

Foci of demyelination

Some diseases of the nervous system are accompanied by damage to the glial membrane of the long processes of neurons. As a result of pathological changes, the conduction of impulses is disrupted. This condition is accompanied by neurological symptoms of varying degrees of intensity. Demyelination of nerve fibers can be caused by:

multifocal leukoencephalopathy;
multiple sclerosis;
dissimulating encephalomyelitis;
Marburg's disease, Devic's disease and many others.

Typically, demyelination lesions appear as multiple small areas of hyperintense MR signal located in one or more parts of the brain. Based on the degree of their prevalence, duration and simultaneity of occurrence, the doctor judges the scale of development of the disease.

Focus of demyelination on MRI

Focus of vascular origin

Cerebrovascular insufficiency causes ischemia of the cerebral substance, which leads to changes in the structure and loss of function of the latter. Early diagnosis of vascular pathologies can prevent stroke. Focal changes of discirculatory origin are found in most patients over 50 years of age. Subsequently, such zones can cause degenerative processes in the brain tissue.

Lacunar cerebral infarction on MRI (indicated by arrow)

Cerebral circulation disorders can be suspected by focal changes in the perivascular Virchow-Robin spaces. The latter are small cavities around the cerebral vessels, filled with fluid, through which tissue trophism and immunoregulatory processes occur (blood-brain barrier). The appearance of a hyperintense MR signal indicates expansion of the perivascular spaces, since they are normally not visible.

Sometimes an MRI of the brain reveals multiple lesions in the frontal lobe or in the deep parts of the hemispheres, which may indicate damage to the cerebral vessels. The situation is often clarified by MR scanning in angio mode.

Foci of ischemia on MRI

Foci of ischemia

Cerebral circulation disorders lead to oxygen starvation of tissues, which can provoke necrosis (infarction). Ischemic lesions on T2-weighted sequences appear as areas with moderately hyperintense signal of irregular shape. At a later stage, when performing MRI in T2 VI or FLAIR mode, a single lesion takes on the appearance of a light spot, which indicates a worsening of destructive processes.

X-ray of the sinuses during pregnancy

The radiation dose during the study is 20 μSv and is considered safe even when performed repeatedly for an adult. The fetus is susceptible to ionizing radiation, which causes intrauterine developmental defects. Carrying a child is a contraindication to the procedure.

X-rays of the nasal sinuses during pregnancy and breastfeeding are done exclusively for health reasons. The potential benefit of the research must outweigh the harm to the child. After the procedure, a pregnant woman needs an ultrasound of the fetus, and a nursing woman needs to transfer the baby to artificial nutrition for a day.

A little about the paranasal sinuses

The paranasal sinuses, or sinuses, are located in the bones of the skull. They are lined with mucous membrane and communicate with the nasal cavity. These formations perform many useful functions: they reduce the mass of the skull bones, warm and moisturize the inhaled air, soften blows to the face, participate in the formation of the timbre of the voice, and help to sense changes in environmental pressure.

Humans have four types of paranasal sinuses:

The most famous are the maxillary ones. As the name suggests, they are found in the upper jaw. These sinuses are also called maxillary sinuses, and inflammation in them is called sinusitis.
The frontal sinuses are located in the frontal bone, just above the bridge of the nose. When inflammation develops in them, frontal sinusitis is diagnosed.
Inside the skull, in the thickness of the ethmoid bone, there is a ethmoid labyrinth. Inflammation in its cells is ethmoiditis.
The sphenoid sinus is the only unpaired sinus. It is located in the bone of the same name, which is located deep in the very center of the skull. Only its wings protrude outward. The inflammatory process in the sphenoid sinus is called “sphenoiditis”.

The general term for inflammation in any of the paranasal sinuses is “sinusitis.”

X-ray of the sinuses for children

Pediatricians try to protect preschool children from the harm caused by X-ray radiation to the fragile skeletal system. The procedure is allowed to be performed on patients over 7 years of age.

Before this period, a clear justification for the importance of intervention is necessary - for example, severe facial trauma or severe sinusitis with a risk of inflammation of the meninges.

It is difficult for a young child to sit or stand still during an x-ray. To distract him, they use toys, sedatives, and in emergency cases, anesthesia. At an older age, you can captivate your child with a game in which you should freeze for a short time.

Which is better: radiography or CT of the paranasal sinuses?

Computed tomography is more informative, and it is used when pathological changes cannot be identified and comprehensively studied using radiography. But this is not always necessary. In addition, CT scans are more expensive and involve higher radiation exposure to the body.

Modern digital X-ray machines allow you to obtain very clear, detailed images, which are often enough to establish an accurate diagnosis and prescribe the correct treatment. This is exactly the device that is used in the ProfMedLab clinic. In our clinic, based on the results of the study, you can get a consultation with one of the leading ENT doctors.

How dangerous is the research?

X-ray is a non-invasive and painless procedure. It can also be called relatively safe, since the radiation exposure is minimal. At the same time, of course, x-rays are not a procedure that can be repeated many times in a row. There are certain norms and frequency that must be observed.

Contraindications for

An absolute contraindication for head x-rays is pregnancy. There are also relative restrictions. These are children under 15 years of age, mental illness, serious condition.

Technique

To take an X-ray, the patient must stand up, sit near the X-ray machine, or lie down on its work table. It is important to remain still and not breathe while filming. If you need to take a picture in several projections, the doctor will tell you how to change the position.

X-ray of the skull in 2 projections

To obtain the most detailed and complete information about the condition of the nasal bones, photographs can be taken in two projections - frontal and lateral. In the first case, the patient faces the X-ray machine, in the second - sideways (left or right).