Neuroendgenological methods of research - Causes, symptoms and treatment. MF.

No matter how perfect the topical diagnosis of diseases of the nervous system, no matter how vast experience the clinician has, anatomical verification of the diagnosis is desirable, and often necessary. For the choice of treatment, especially if it is a neurosurgical operation, you need clear ideas about the nature, exact location and size of the pathological process, its relation to the surrounding brain structures, etc. Answers to these questions give radiopaque methods of research that provide visualization of the pathological process. Some of these research methods, such as pneumoencephalography and ventriculography with air, which appeared at the beginning of the 20th century, are now practically not used, giving way to more informative and safe methods, such as computer and MR tomography of the brain and spinal cord.

Craniography.

The skull has a complex anatomical structure, therefore, in addition to the survey images in the direct and lateral projections, special sighting pictures are made. Craniography allows to recognize congenital and acquired deformities of the skull, traumatic bone injuries, primary and secondary tumor processes, some inflammatory changes, fibrotic dysplasia, manifestations of a number of endocrine diseases and other lesions. With craniography, intracranial physiological and pathological calcifications are revealed, which, by their displacement, determine the side of the location of the hemispheric volumetric process.

For topical diagnosis, it is important to identify on the roentgenograms local bone changes caused by the impact of the intracranial pathological process( hyperostosis, usuras, increased development of vascular furrows, etc.).Typical local changes in the Turkish saddle with tumors of the pituitary gland, expansion of the internal auditory canal with neurinomas of the VIII cranial nerve, widening and altering the edges of the optic nerve hole in gliomas, etc.

In the X-ray examination, one can find common signs of hydrocephalus: change in the shape of the skull,foundation, strengthening of the vascular pattern of the bones of the arch. General changes in the skull due to a prolonged increase in intracranial pressure are revealed: secondary changes in the Turkish saddle, shortening and porosity of its back, porosity of the anterior and posterior oblique processes, widening of the entrance to the saddle and deepening of the bottom, changes in the structure of the bones of the arch in the form of so-called finger impressions,cranial sutures.

Spondylography.

Radiographic examination of the spine is usually performed in lateral and direct projections. If necessary, they make sighting X-rays and images in special projections. Spondylography can reveal pathological curvatures of the spine( kyphosis, scoliosis, rotation along the axis), anomalies in the development of the vertebrae. It is the main method of diagnosing traumatic spine injuries, nonspecific and specific( tuberculosis) lesions.

X-ray examination allows to detect various manifestations of vertebral osteochondrosis: narrowing of intervertebral spaces, change of vertebral bodies, posterolateral osteophytes, uncovertebral arthrosis, etc. It is important to establish the size of the spinal canal, especially its sagittal diameter. It is possible to identify the instability of the vertebral segment, the displacement of the vertebrae( spondylolisthesis).

Spondylography makes it possible to detect changes in tumors of the spinal cord and its roots: widening of the intervertebral foramen with neurinoma of the spinal roots, destruction of the vertebral arches with extramedullary tumors, local expansion of the spinal canal. Destruction of vertebral bodies with metastatic tumors is also revealed.

Radiocontrast study of cerebrospinal fluid. Contrast substances used in the X-ray study of cerebrospinal and spinal cord cerebrospinal fluid can be different. Water-soluble substances( croups, dimer-x, amipac), easily mixing with cerebrospinal fluid, give good contrasting( as it were, impressions of the ventricles of the brain and subarachnoid space), but the occlusion level can not always be clearly detected. For these purposes, it is better to use heavy contrast agents, the relative density of which is greater than 1.0( majodil, iodidephenylate).

For contrasting liquor pathways, gases - air, oxygen, helium can be used.

Ventriculography.

Radiocontrast study of the ventricles of the brain is used mainly in the differential diagnosis of occlusal and open( communicating) hydrocephalus. The study begins with a puncture of the anterior or posterior horn of the lateral ventricle. With ventriculography with mayodil, the puncture of the anterior horn of the lateral ventricle is performed in the position of the patient lying down, and the contrast medium( 1.5-2.0 ml) is injected in the sitting position;The head is slightly tilted forward and in the opposite direction. In the absence of blockade of the cerebrospinal fluid, a heavy contrast substance penetrates through the interventricular orifices into the third ventricle, the midbrain waterway, the IV ventricle, the large cistern and the vertebral canal. The presence of an obstacle creates a delay in the contrast medium, which is determined on the radiographs of the skull, made in two projections. Ventriculography should not be performed with tumors, hematomas, abscesses, parasitic cysts of the cerebral hemispheres, as it significantly worsens the condition of patients, giving me scant information.

Pneumoencephalography.

X-ray examination of the ventricles of the brain and subarachnoid space by introducing air into the subarachnoid space in the patient's position sitting through the lumbar puncture. The implementation of this procedure is possible by two methods, significantly different from each other: with excretion and without removal of cerebrospinal fluid. In pneumoencephalography, the first method, trying to achieve a good filling of the ventricles of the brain and subarachnoid space, inject large amounts of air( up to 60-80 ml or more) and, in order not to cause a significant increase in intracranial pressure, the cerebrospinal fluid is withdrawn in parallel. With pneumoencephalography without the removal of the cerebrospinal fluid, air is introduced in a small amount( not exceeding 20-25 ml) slowly and strictly directed into the area of ​​the supposed localization of the pathological process. If there is a need to introduce air into the subarachnoid spaces of the base of the brain( into the cisterns), then during manipulation, the patient's head is thrown back as much as possible. X-ray and tomography of the skull in two projections are performed in the patient's sitting position. This method is called pneumocysternography, respectively. Although ventriculo and pneumoencephalography make it possible to clarify the nature and localization of a number of pathological processes( tumors, consequences of craniocerebral trauma, vascular and inflammatory diseases), they have been practically not used lately, because they are invasive and inferior in their informativeness to computer and magnetic resonance imaging.

Myelography.

Introduction of a contrast medium into the subarachnoid space of the spinal cord with subsequent radiography of the spine provides an opportunity to clarify the nature and localization of the pathological process. Myelography is indicated for tumors of the spinal cord, herniated intervertebral discs, chronic spinal arachnoiditis and other pathological processes that limit the lumen of the spinal canal.

There are myelograms ascending and descending depending on the type and relative density of the contrast medium. With descending myelography with the introduction of majodil into a large cistern, suboccipital puncture is performed, 2-3 ml of cerebrospinal fluid is extracted and an equal amount of majodil is injected. X-ray examination is performed in the patient's position sitting or lying on a table with an elevated head end. In the block of the subarachnoid space of the spinal cord, the contrast stops above the pathological focus( the "rider" symptom).

With ascending myelography, a contrast agent is injected through the lumbar puncture. Radiographic examination of the spine is performed at the lowered head end of the table. In this case, the lower limit of the obstacle to the liquor may be detected.

Air can be used as a contrast agent( pneumomielography) and radioactive inert gas - xenon( isotope myelography).In the latter case, the distribution of xenon in the subarachnoid space is determined using a highly sensitive radio scintillation counter.

In the presence of magnetic resonance imaging, indications for myelography are limited.

Radiocontrast study of blood vessels.

Cerebral angiography.

Contrast substance is injected into the main vessels of the head and makes rapid serial X-ray photography on devices of a special design. Angiographic methods can be conditionally divided into direct ones, in which the puncture of the carotid or vertebral artery is performed, and catheterization, when the contrast substance is introduced into the main vessels of the head through their catheterization through the femoral, axillary or brachial arteries. Cerebral angiography allows us to clarify the nature and localization of the pathological process and is used in the diagnosis of brain tumors, vascular malformations( arterial and arteriovenous arteriovenous arteriovenous aneurysms, arteriovenous anasthenia), some forms of stroke to clarify the indications for surgery, and to monitor the results of a number of surgical interventions.

Angiography is important for the study of collateral blood supply and the determination of the rate of cerebral blood flow. Isolate the arterial, capillary and venous phases of passage of contrast medium along the vessels of the brain. Normally, the contrast leaves the cerebral vascular bed of the brain for 8-9 seconds, but with a sharp increase in intracranial pressure due to a tumor, hematoma, hydrocephalus, cerebral edema, the time of cerebral circulation may extend to 15-20 seconds. With an extreme degree of intracranial hypertension and brain death, there is a stopping of cerebral circulation - contrast material does not enter the vessels of the brain. Acceleration of cerebral blood flow is observed with arteriovenous aneurysms and anastomosis.

Spinal angiography.

Spinal angiography is also performed by catheterization of arteries that supply blood to the spinal cord at different levels. The need for this complex and time-consuming study arises when there is a suspicion of arteriovenous malformation of the spinal cord and some spinal tumors.

any radiation study should be justified, that is, it should be followed by strict indications. The main argument should be the need to obtain important diagnostic information. With the same information, preference should be given to those studies that are not related to the irradiation of the patient or are accompanied by less radiation. With special care approach to the screening( preventive) radiation studies. X-ray examinations are not performed for pregnant women and children under 14 years of age. X-ray studies related to the irradiation of the genitals( studies of the intestines, kidneys, lumbar spine, pelvis, etc.), women in childbearing age are recommended to be conducted during the first week after menstruation. Restriction of the use of X-ray studies during pregnancy is associated with the potential risk of adverse effects of additional radiation on fetal development. Although the vast majority of medical procedures using X-rays do not expose a developing child to critical radiation and a significant risk, in some cases there may be a small probability of a negative effect of X-radiation on the fetus. The risk of an X-ray examination depends on the duration of pregnancy and the type of procedure performed. When examining the head, limbs, chest with the use of special protective aprons for a pregnant woman, as a rule, the child is not exposed to direct exposure to the rays and, therefore, the examination procedure is almost safe for him. Only in rare cases, during pregnancy, there is a need to conduct an X-ray examination of the abdominal or pelvic area, but even in such a situation the doctor can prescribe a special type of examination or, if possible, limit the number of examinations and the area of ​​exposure. Due to the fact that the overwhelming number of X-ray examinations in pregnant women are carried out according to vital indications( the need to eliminate pneumonia or tuberculosis), the risk of carrying out these studies for the mother and the unborn child is always incomparably lower than the possible harm that can befall them from the examination. Procedures using conventional X-rays( conventional X-rays, fluorography, computed tomography) are safe for nursing mothers. X-rays do not affect the composition of breast milk. In the case of nursing mothers, a certain danger is posed only by X-ray examinations, which involve the introduction of radioactive substances. Before such a test, nursing mothers should be informed of lactation to the doctors, as some drugs may enter milk. In order to avoid the impact of radioactive substances on the child's organism, doctors are likely to advise the mother to interrupt the feeding for a short time, depending on the type and amount of radioactive material used. As in the case of pregnant women, an X-ray examination of children is carried out according to vital signs and its risk is almost always lower than the possible risk of the disease, which is being examined.