Open AccessEvaluation of cerebral microstructural changes in adult patients with obstructive sleep apnea by MR diffusion kurtosis imaging using a whole-brain atlas
Author(s) -
Sameer Vyas,
Paramjeet Singh,
Niranjan Khandelwal,
Varan Govind,
Ashutosh N. Aggarwal,
Manju Mohanty
Publication year - 2019
Publication title -
indian journal of radiology and imaging - new series/indian journal of radiology and imaging/indian journal of radiology and imaging
Language(s) - English
Resource type - Journals
eISSN - 0971-3026
pISSN - 0970-2016
DOI - 10.4103/ijri.ijri_326_19
Subject(s) - kurtosis , medicine , diffusion mri , fractional anisotropy , obstructive sleep apnea , neuroimaging , brain mapping , magnetic resonance imaging , nuclear medicine , cardiology , radiology , psychiatry , statistics , mathematics
Purpose: The association between obstructive sleep apnea (OSA) and cognitive impairment is well-recognized, but little is known about neural derangements that underlie this phenomenon. The purpose of this study was to evaluate the utility of diffusion kurtosis imaging (DKI) using a whole-brain atlas to comprehensively assess microstructural tissue changes in the brain of patients with OSA. Methods: This prospective study was conducted in 20 patients with moderate-to-severe OSA and 20 age- and gender-matched controls. MRI data acquisition was performed with 3 Tesla and data was analyzed using a whole-brain atlas. DKI data were processed and transformed into a brain template space to obtain various kurtosis parameters including axial kurtosis (AK), radial kurtosis (RK), mean kurtosis (MK), and kurtosis fractional anisotropy (KFA) using a 189-region brain atlas in the same template space. These kurtosis measurements were further analyzed using a student t-test in order to determine kurtosis measurements that present significant differences between the OSA patient set and the control set. Results: Significant differences (P < 0.05) were found in AK (54 regions), RK (10 regions), MK (6 regions) and KFA (41 regions) values in patients with OSA as compared to controls. DKI indices, using an atlas-based whole-brain analysis approach used in our study, showed widespread involvement of the anatomical regions in patients with OSA. Conclusion: The kurtosis parameters are more sensitive in demonstrating abnormalities in brain tissue structural organization at the microstructural level before any detectable changes appear in conventional MRI or other imaging modalities.