Measurement of cerebral perfusion in parkinson's diasease with mild cognitive impairment using arterial spin labeling MRI

Abstract

Mild cognitive impairment is a common symptom of Parkinson’s disease (PD). Objective imaging biomarkers are required for the diagnosis of PD with mild cognitive impairment (PD-MCI). Arterial spin labeling MRI (ASL-MRI) enables the measurement of cerebral blood flow (CBF) without using contrast agent or ionizing radiation. In this study, ASL-MR images of 19 PD-MCI and 19 cognitively normal PD (PD-CN) patients were acquired at 3T. CBF maps were calculated with arterial blood volume (aBV) correction using the quantitative imaging of perfusion using a single subtraction (QUIPSS II) formula. CBF and aBV maps were fused into T2 weighted (T2w) MR images, and registered to MNI152 brain atlas in FSL. The CBF and aBV values of several brain regions were compared between PD-MCI and PD-CN patients. The differences in histogram parameters of CBF maps, which were estimated with and without aBV correction, were assessed. The correlations between the neuropsychological test scores and CBF values were assessed. The CBF values in different brain regions of each group were compared with each other. A graphical user interface (GUI) was designed in order to calculate CBF maps out of ASL-MRI in MATLAB. There were not any statistically significant differences between the CBF values of PD-MCI and PD-CN patients. There were some variations between the CBF values of the brain regions in PD-MCI and PD-CN groups. There was a trend of a negative correlation between the neuropsychological test scores and the CBF values in some brain regions of PD-MCI patients. The results of this study combined with other MR parameters might enable the definition of an MR based biomarker for PD-MCI diagnosis.|Keywords : Arterial spin labeling, Parkinson’s disease, mild cognitive impairment, QUIPSS II, cerebral blood flow.