White matter hyperintensities classified according to intensity and spatial location reveal specific associations with cognitive performance
Melazzini L., Mackay CE., Bordin V., Suri S., Zsoldos E., Filippini N., Mahmood A., Sundaresan V., Codari M., Duff E., Singh-Manoux A., Kivimaki M., Ebmeier KP., Jenkinson M., Sardanelli F., Griffanti L.
<jats:p>White matter hyperintensities (WMHs) on T<jats:sub>2</jats:sub>-weighted images are radiological signs of cerebral small vessel disease. As their total volume is variably associated with cognition, a new approach that integrates multiple radiological criteria is warranted. Location may matter, as periventricular WMHs have been shown to be associated with cognitive impairments. WMHs that appear as hypointense in T<jats:sub>1</jats:sub>-weighted images (T<jats:sub>1</jats:sub>w) may also indicate the most severe component of WMHs. We developed an automatic method that classifies WMHs into four categories (periventricular/deep and T<jats:sub>1</jats:sub>w-hypointense/nonT<jats:sub>1</jats:sub>w-hypointense) using MRI data from 684 community-dwelling older adults from the Whitehall II study. To test if location and intensity information can impact cognition, we derived two general linear models using either overall or subdivided volumes. Results showed that periventricular T<jats:sub>1</jats:sub>w-hypointense WMHs were significantly associated with poorer performance in several cognitive tests. We found no association between total WMH volume and cognition. These findings suggest that classifying WMHs according to both location and intensity in T<jats:sub>1</jats:sub>w adds value over and above total WMH volume.</jats:p>