Evaluation of white matter damage in patients with Alzheimer's disease and in patients with mild cognitive impairment by using diffusion tensor imaging.
OBJECTIVE
The objective of this study was to evaluate white matter tissue damage in patients with Alzheimer's disease (AD) and in patients with mild cognitive impairment (MCI) using diffusion tensor imaging (DTI).


METHODS
Forty-seven subjects were evaluated: 14 patients with AD, 15 with MCI and 18 healthy volunteers. All subjects were studied using conventional magnetic resonance imaging (MRI) and DTI (32 directions) with a 1.5 T magnet. Fractional anisotropy (FA) was measured in the following regions: frontal, occipital, parietal and temporal white matter and in the genu and splenium of the corpus callosum. The results were compared between the different groups and correlated with the Mini-Mental State Evaluation (MMSE) scores.


RESULTS
A statistically significant difference was obtained between controls and MCI patients (p < 0.007) and between controls and AD patients (p < 0.05) with regard to FA of the white matter in the splenium. A statistically significant difference was obtained between controls and AD patients with regard to FA in the genu (p < 0.016). Moreover, there was a statistically significant difference between controls and AD patients considering the genu (p < 0.016) and the frontal white matter on the right side (p < 0.024). The MMSE scores correlated with the FA values measured in the genu, the splenium and frontal white matter on the right side. No significant differences were identified between patients with AD and those with MCI.


CONCLUSIONS
DTI could be of value in the early detection of white-matter damage in patients with MCI and AD. The DTI values correlate with the neuropsychological tests.
Ukmar
M
M
Unità Clinica Operativa di Radiologia, Università degli Studi di Trieste, Ospedale di Cattinara, Strada di Fiume 447, 34149, Trieste, Italy. majaukmar@alice.it
Makuc
E
E
Onor
M L
ML
Garbin
G
G
Trevisiol
M
M
Cova
M A
MA
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000473:pathology; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000473:pathology; D003337:Corpus Callosum / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D009778:Occipital Lobe / Q000473:pathology; D010296:Parietal Lobe / Q000473:pathology; D013702:Temporal Lobe / Q000473:pathology