Thalamic lesions in vascular dementia: low sensitivity of fluid-attenuated inversion recovery (FLAIR) imaging.
OBJECTIVE
The criteria of the National Institute of Neurological Disorders and Stroke (NINDS)-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN) include thalamic lesions for the diagnosis of vascular dementia (VaD). Although studies concerning VaD and brain aging advocate the use of fluid-attenuated inversion recovery (FLAIR) or T2-weighted images (T2-WI) to detect ischemic lesions, none compared the sensitivity of these sequences to depict thalamic lesions.


METHODS
We performed a blinded review of T2-WI and FLAIR images in 73 patients fulfilling the radiological part of the NINDS-AIREN criteria (mean age, 71 years; range, 49 to 83 years). This sample was drawn from a large multicenter trial on VaD and was expected to have a high prevalence of thalamic lesions. In a side-by-side review, including T1-weighted images as well, lesions were classified according to presumed underlying pathology.


RESULTS
The total number of thalamic lesions was 214. Two hundred eight (97%) were detected on T2-WI, but only 117 (55%) were detected on FLAIR (chi(2)=5.1; P<0.05). Although the mean size of lesions detected on T2-WI and not on FLAIR (4.4 mm) was significantly lower than the mean size of lesions detected on both sequences (6.7 mm) (P<0.001), 5 of the 29 lesions >10 mm on T2-WI were not visible on FLAIR. FLAIR detected only 81 (51%) of the 158 probable ischemic lesions and 30 (60%) of the 50 probable microbleeds.


CONCLUSIONS
FLAIR should not be used as the only T2-weighted sequence to detect thalamic lesions in patients suspected of having VaD.
Bastos Leite
António J
AJ
Department of Radiology, Vrije Universiteit Medical Center, Amsterdam, Netherlands.
van Straaten
Elisabeth C W
EC
Scheltens
Philip
P
Lycklama
Geert
G
Barkhof
Frederik
F
D000368:Aged; D000369:Aged, 80 and over; D002219:Carbamates / Q000627:therapeutic use; D017326:Clinical Trials, Phase III as Topic / Q000706:statistics & numerical data; D015140:Dementia, Vascular / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D008875:Middle Aged; D015337:Multicenter Studies as Topic / Q000706:statistics & numerical data; D048448:Phenylcarbamates; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D000068836:Rivastigmine; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D013788:Thalamus / Q000473:pathology*
D002219:Carbamates; D048448:Phenylcarbamates; D000068836:Rivastigmine