Comparisons of Different CEST Quantification Metrics Applied in Acute Parkinson's Disease Mouse Model

Abstract

Non-invasive and quantifiable diagnosis of Parkinson's disease (PD) is an ongoing challenge for researchers. In this study, we compared two different chemical exchange saturation transfer (CEST) imaging quantification metrics in substantia nigra (SN), cortex and hippocampus of acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice at three different time points including before MPTP administration, and the 3rd and 10th day after MPTP administration. Area of amine (Areaamine), magnetization transfer ratio yielding Rex (MTRrex) and apparent exchange-dependent relaxation (AREX) in SN derived from 5-pool Lorentzian fitting and inverse Z-spectrum analysis showed a statistically significant decrease after successful modeling, while there were no significant alterations in T1, T2, and magnetization transfer ratio based on asymmetry analysis (MTRasym). The results suggested that the former quantification is superior to that based on Z-spectrum asymmetry in vivo due to the exclusion of direct saturation (DS) and magnetic transfer (MT) effects and may reflect the destroying SN of PD.

Keywords

• magnetic resonance imaging (MRI)
• chemical exchange saturation transfer (CEST)
• Lorentzian fitting
• inverse Zspectrum analysis
• 1-methyl-4-phenyl-1
• 2
• 3
• 6-tetrahydropyridine (MPTP)