Background. Atrophy in medial temporal lobe (MTL) structures detected in vivo through brain imaging is one of the most accurate markers of AD, but practical considerations have so far limited their use in the clinical routine. The aim of this study is to explore the validity of a CT-based measure of medial temporal lobe atrophy that is sufficiently feasible to be routinely employed. Methods. Brain CT images were acquired at an appropriately angulated plane with thin slices in 42 Alzheimer's patients and 29 non-demented controls. The radial width of the temporal horn (rWTH) of the lateral ventricle (URL: www.centroalzheimer.it) was measured at the tip of the horn on CT films with a precision caliper. The validity of the rWTH was assessed by test-retest and inter-rater reliability, convergent and discriminant validity versus progressively distant brain regions, and known-group validity (accuracy of the separation of AD patients from controls). Convergent and discriminant validity versus volumetric measures was also tested in a historical MR database. Results. Intraclass correlation coefficients for inter-rater and intra-rater reliability were between 0.94 and 0.98. Pearson's correlation of the rWTH with the transverse temporal horn width was between 0.60 and 0.79, with Jobst's minimum thickness of the MTL between 0.63 and 0.78, with the interuncal distance about 0.50, and with an index of frontal atrophy between 0.35 and 0.42. The rWTH was able to discriminate AD patients from non-demented controls with 93% sensitivity and 95% specificity. Pearson's correlation with volumetric MR measures was 0.80 with the temporal horn, 0.74 with the hippocampus, 0.68 with the temporal lobe, 0.58 with the entorhinal cortex, and 0.49 with the frontal lobe. Conclusions. The rWTH is an accurate marker of AD that could be used in routine clinical settings.
|Issue number||4 SUPPL.|
|Publication status||Published - 2000|
ASJC Scopus subject areas
- Clinical Neurology