MRI of brain vessels: what shows?
Chronic disease and the effects of acute critical conditions developed on the background of pathological changes in the vessels are the most common causes of regular monitoring by a neurologist. Vascular diseases occupy a leading position in the structure of organic pathologies of the Central nervous system – 17% of all diseases. By far the most informative and safe method to visualize the structure of the brain is recognized as magnetic resonance imaging (MRI). For MRI of the head vessels have resorted not only to confirm the diagnosis when suspected vascular lesion, but also as an evaluation of the effectiveness of the therapy to make the appropriate adjustments. Thanks to the MRI we can determine the anatomical structure of blood vessels, the presence of abnormal changes in veins, arteries and capillaries, the localization of the lesion, the volumes of cerebral blood flow and the degree of its violation.
Mr angiography is an effective method of research vessels
MRI of cerebral arteries angiography method allows to obtain visual information about the status of blood vessels without using contrast agents. In some severe cases with a questionable diagnosis for a clear visualisation of veins and arteries using a special contrast agent with a magnetizable component.
The importance of MRI for the diagnosis of hydrocephalus (excessive accumulation of cerebrospinal fluid in the cranial cavity) in infants, children from other age periods and adults. The survey results enable to determine the degree of progressive pathology, as well as to visually identify the presence of cerebral malformations – abnormal-weave veins and arteries of the brain. The clinical symptoms of normal pressure hydrocephalus: gradual development of walking disorders, urinary incontinence, dementia, MRI shows the extension of the segments of the ventricular system, the deformation of the branches of arteries, the change in the density of the substance of the brain.
When seizures are advised to immediately resort to imaging to establish a provoking factor, e.g., tumors. Indications for study: multiple sclerosis and Alzheimer’s disease.
If you suspect a brain tumor and other structures of the skull for diagnosis resort to MRI. The primary goal of diagnostic procedures to differentiate the type of tumor that allows to make a reliable prediction, and choose the suitable program of therapy. The results obtained allow neurosurgeons to judge about the localization of the tumor and its structural features. The image is well monitored segments of the vascular system: veins, arteries, capillaries, and lichborne space. In the case of the use of methods of radiation exposure, in particular: irradiation of the broad gamma-ray beams, the CT scan shows the probability of radiation injuries of the brain. Doctor’s task is to constantly monitor the condition of the patient having a brain tumor, and as the priority method of diagnostic survey to recommend the scan.
Indications for MRI examination is the presence of symptoms of infectious and degenerative lesions of the brain. An abscess is diagnosed when there is formed a thin capsule, which looks like a bulk phase round shape with a smooth clear path. When examined in the T2 mode about the presence of an abscess informs the increase of signal in the zone of purulent focus. By MRI can confirm or deny the development:
- tuberculosis infection;
- viral encephalitis;
- parasitic lesions.
Diagnosis of circulatory disorders
Indications for MRI of a variety of circulatory disorders in the brain:
- ischemic stroke;
- intracerebral hemorrhage by the type of hemorrhagic infarction or hematoma;
- hemorrhage in the subarachnoid space;
- epidural and subdural hematomas of unknown origin;
- form of hypertensive encephalopathy;
- thrombosis of the venous system purulent character;
- dementia of the vascular type.
The results of the MRI indicate degenerative lesions in various forms of metabolic encephalopathy: hepatic, uremic, diabetic, pancreatic. It is also recommended to conduct Mr-angiography patients children and adolescents with suspected acute disorders of cerebral blood flow.
The MRI of the veins and arteries of the brain in disorders of blood supply
Ischemic stroke requires confirmation of the diagnosis by CT examination of the veins and arteries, as without such data the likelihood of medical errors exceed 5%. MRI gives information that allows you to differentiate an ischemic stroke from a brain hemorrhage, tumors, traumatic brain injury, multiple sclerosis, dysmetabolic and toxic encephalopathies. When Mr imaging fails to detect even small-sized lesions localized in the brain stem. By Mr-angiography to identify rare forms of stroke, triggered by stratification of the arteries, the contraction or expansion of the lumen, stenosis and thrombosis, anguish of the inner shell.
Indications for study: all cases of transient ischemic attacks to the exclusion of other probable causes that triggered neurological disorders. In the majority of patients with transient ischemic attacks are not detected focal changes of the brain.
A leading research method for symptoms of a brain hemorrhage in the acute period (after one day) – magnetic resonance imaging. MRI-angiography allows to detect the cause of bleeding, such as: arteriovenous malformation. The standard survey about arteriovenous malformations informs the presence of the compact area of heterogeneous signal changes. The doctor can visualize not only the damaged artery, but also to define the area of ischemia, the area of atrophy and the presence of hemorrhage. In hemorrhagic stroke, MRI shows typical signs of resorption of hematoma – formation of cysts.
For the diagnosis of cerebral aneurysms in acute period of subarachnoid hemorrhage preferred Mr angiography, which, owing to its noninvasiveness, high resolution, three-dimensional projection gives a qualitative picture of the blood vessels of the brain and to determine the source of the problem.
Thanks to magnetic resonance imaging a possible diagnosis in the initial phase of the pathology, which is important for timely development of adequate and comprehensive therapeutic strategies.