Application of Diffusional Kurtosis Imaging on Normal-Appearing White Matter in Cerebral Small Vessel Disease.

Background: This study aimed to investigate the diagnostic potential of diffusional kurtosis imaging (DKI) parameters in detecting pathological alterations in the normal-appearing white matter (NAWM) associated with cerebral small vessel disease (CSVD).

Methods: A total of 56 patients diagnosed with CSVD were enrolled, all exhibiting confirmed lacunar infarction in the corticospinal tract (CST) as verified by conventional magnetic resonance imaging. A control group of 24 healthy individuals who exhibited no discernible abnormalities on conventional magnetic resonance imaging (MRI) scans was also included. The following DKI parameters were recorded, including mean kurtosis (MK), axial kurtosis (Ka), and radial kurtosis (Kr). Regions of interest were placed at representative levels of the CST on the affected side, encompassing the pons, anterior part of the posterior limb of the internal capsule (PLIC), corona radiata, and subcortex.

Results: Variations in MK, Ka, and Kr values in the pons, anterior part of the PLIC, corona radiata, and subcortex of the control group were observed. Notably, the MK and Kr values of the normal-appearing pons in CSVD patients were significantly elevated compared with the control group. The MK, Ka value of the normal-appearing anterior part of the PLIC was significantly higher in the CSVD group than in the control group. The Kr value of the normal-appearing corona radiata exhibited a significant elevation in CSVD patients compared with the control group. Lastly, patients with CSVD displayed lower Ka values and higher Kr values in the normal-appearing subcortex compared with the control group.

Conclusions: DKI is an effective tool for assessing NAWM in patients with CSVD. These findings potentially offer novel insights into the prognosis of CSVD and serve as a foundational platform for future DKI studies on NAWM in other diffuse brain lesions.