Clinical Neuroscience

[Application of diffusion weighted imaging in neuroradiology]

BARSI Péter

MARCH 25, 2009

Clinical Neuroscience - 2009;62(03-04)

[Diffusion weighted magnetic resonance (MR) imaging is available on all modern MR scanners. It depicts the motion of water molecules in the brain tissue and intracranial foreign tissues and provides information on changes in the proportion of intra- and extracellular space and the characteristics of foreign intracranial tissues and fluids. It is of utmost importance eg. in the diagnostics and differential diagnostics of acute ischaemic brain lesions, the diagnostics of inflammatory brain processes and in the differential diagnostics of intracranial space-occupying lesions. The examination method of short scanning and post-processing time must be completed with the apparent diffusion coefficient (ADC) maps and it is indispensable in the everyday neuroradiological diagnostics. Diffusion tensor imaging and tractography are able to depict the white matter tracts. They require a longer scanning and post-processing time and have several technical problems yet to be solved, but they provide help in their current state e.g. in the surgical planning of intracranial space-occupying lesions.]

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[Inflammatory diseases of the central nervous system (CNS) are relatively rare in children, but their relevance to public health is considerable due to frequent and significant long term morbidity and even mortality. As in adults, acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) and their variants are the most common entities in this group of pathologies in the pediatric patient population. Recent efforts have focused on establishing standardized diagnostic criteria schemes to facilitate the diagnosis and differential diagnosis of these diseases, however especially with multiple sclerosis those have not been fully validated yet for disease occurring in children. In recent decades the role of MRI has been constantly increasing in the diagnostic work-up of suspected inflammatory diseases of the CNS as well as in the follow-up of patients with confirmed disease. Currently, MRI is the first-line diagnostic imaging modality in ADEM and MS and is fully integrated in the most widely used diagnostic criteria schemes, but it has a key role in clinical therapeutic research trials as well. This paper provides an update on the current concepts and strategies of MRI in inflammatory diseases of the CNS, as well as a review of the imaging semiology of the various disease entities and variants with emphasis on clinical and imaging particularities relevant to the pediatric patient population.]

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