ADC histograms from routine DWI for longitudinal studies in cerebral small vessel disease: a field study in CADASIL.

[cadasil]

Diffusion tensor imaging (DTI ) histogram metrics are correlated with clinical parameters in cerebral small vessel diseases (cSVD ). Whether ADC histogram parameters derived from simple diffusion weighted imaging (DWI ) can provide relevant markers for long term studies of cSVD remains unknown . CADASIL patients were evaluated by DWI and DTI in a large cohort study over a 6 -year period . ADC histogram parameters were compared to those derived from mean diffusivity (MD ) histograms in 280 patients using intra-class correlation and Bland-Altman plots . Impact of image corrections applied to ADC maps was assessed and a mixed effect model was used for analyzing the effects of scanner upgrades . The results showed that ADC histogram parameters are strongly correlated to MD histogram parameters and that image corrections have only limited influence on these results . Unexpectedly , scanner upgrades were found to have major effects on diffusion measures with DWI or DTI that can be even larger than those related to patients ' characteristics . These data support that ADC histograms from daily used DWI can provide relevant parameters for assessing cSVD , but the variability related to scanner upgrades as regularly performed in clinical centers should be determined precisely for longitudinal and multicentric studies using diffusion MRI in cSVD .