MRI of the brain in case of a stroke

Depending on the cause of the stroke, different features can be seen in the MRI. MRI is considered to be more accurate and reliable than CT, since it can detect even very small stroke foci. The only drawbacks are the much higher cost factor and the longer time to complete the image, which is out of the question in an acute emergency.

A distinction can be made between a “hemorrhagic” stroke, i.e. a loss of brain tissue due to bleeding from a torn cerebral vessel, and an “ischemic” stroke, in which the brain tissue is lost due to reduced blood flow caused by a blocked, occluded cerebral vessel (e.g. a blood clot = thrombus, embolus). “Bloody” areas of the brain appear brighter in a contrast-enhanced MRI image than the rest of the healthy area. In contrast, areas of the brain that have been lost due to vascular occlusion appear darker. In addition, the MRI examination can also include a special imaging of brain vessels (magnetic resonance angiography, MRA), so that blocked or ruptured vessels can be imaged and localized.

MRT of the brain in dementia

MRI is used in the diagnosis of dementia to distinguish between primary and secondary dementia. Primary dementia is an independent dementia disease, such as Alzheimer’s dementia.Characteristic for these primary dementias are so-called brain tissue atrophies, i.e. a loss of brain substance or a decrease in brain volume. This can be recognized in the MRI by a too thin cerebral cortex, flattened brain convolutions, widened and deepened brain furrows as well as enlarged brain water chambers. The MRI is therefore used to differentiate between the primary forms of dementia, which is important for subsequent treatment. On the other hand, MRI can also be used to rule out secondary dementias, i.e. dementias that develop as a result of other diseases, such as tumors, abscesses, water retention or cerebral infarctions.