ADC Histograms from Routine DWI for Longitudinal Studies in Cerebral Small Vessel Disease: A Field Study in CADASIL

Abstract

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 overa6-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.

A Novel Imaging Marker for Small Vessel Disease Based on Skeletonization of White Matter Tracts and Diffusion Histograms

“…Furthermore, it has already been suggested that DTI parameters in general and MD histogram metrics in particular are largely reproducible across different scanners and sequences. Although we cannot fully exclude an influence of scanner type, field strength, and different software versions on MD values, our interscanner reproducibility study using 2 scanners with different field strengths showed the best reproducibility for PSMD. It is plausible that PSMD is less prone to interscanner and interstudy differences than other DTI (histogram) parameters, because peak width does not depend on absolute MD values but rather on the distribution pattern of the histogram.…”

Diffusion Tensor Imaging to Map Brain Microstructural Changes in CADASIL

“…ROI and histogram analyses of DWI and DTI, which have been employed in previous diffusion‐MRI studies of CADASIL, are characterized by intrinsic limitations. For instance, ROI analysis is biased by a priori selection of a limited number of regions under study, and may suffer from not negligible intra‐ and interoperator variability when ROIs are manually placed .…”

“…In particular, using regions of interest (ROI) or histogram analyses, increase of the apparent diffusion coefficient (ADC) or of the mean diffusivity (MD) and decrease of the fractional anisotropy (FA) were observed in CADASIL as compared to healthy controls. Also, histogram measurements of diffusion indices were capable to detect progression of microstructural changes and were recommended for longitudinal studies …”

Injuries of neural tracts in a patient with CADASIL: a diffusion tensor imaging study

“…By contrast, diffusion tensor tractography (DTT), which is derived from diffusion tensor imaging (DTI), has enabled three-dimensional visualization and estimation of the neural tracts. Since the introduction of DTI, several DTI studies have reported on the usefulness of DTI for detection of lesions of CADASIL [ 4 – 8 ]. However, no study on neural tract injury in patients with CADASIL has been reported so far.…”