Assistant Professor of Radiology Tabriz University of Medical Scince*
Imaging nowadays extends beyond its traditional role of excluding neurosurgical lesions. An MR-study of a patient suspected of having dementia must be assessed in a standardized way; First of all, treatable diseases like subdural hematomas, tumors and hydrocephalus need to be excluded
and Next we should look for signs of specific dementias which includes Alzheimer’s disease (AD): medial temporal lobe atrophy (MTA) and parietal atrophy and Alzheimer’s disease (FTLD): (asymmetric) frontal lobe atrophy and atrophy of the temporal pole and Vascular Dementia (VaD): global atrophy, diffuse
white matter lesions, lacunes and ‘strategic infarcts’ (infarcts in regions that are involved in cognitive function) and Dementia with Lewy bodies (DLB): in contrast to other forms of dementia usually no specific abnormalities!
Standardized assessment of the MR findings in a patient suspected of having a cognitive disorder includes: GCA-scale for Global Cortical Atrophy ,MTA-scale for Medial Temporal lobe Atrophy ,Koedam score for parietal atrophy, Fazekas scale for WM lesions and looking for strategic infarcts.
GCA-scale is used for Global Cortical Atrophy assessment and is mean score for cortical atrophy throughout the complete cerebrum
MTA-scale is used for Medial Temporal lobe Atrophy and should be rated on coronal
T1-weighted images and Select a slice through the corpus of the hippocampus, at the level of the anterior pons.
Fazekas scale provides an overall impression of the presence of WMH in the entire brain and best scored on transverse FLAIR or T2- weighted images.
Strategic infarctions are infarctions in areas that are crucial for normal cognitive functioning of the brain
Koedam score is used for Parietal lobe Atrophy and In addition to medial temporal lobe atrophy, parietal lobe atrophy also has a positive predictive value in the diagnosis of AD. keywords: dementia, MRI, Alzheimer’s disease, Vascular Dementia, Strategic