ABSTRACT Purpose To develop a processing pipeline combining neuroimaging analysis tools with CEST postprocessing and utilize it in a pilot study probing differences between cognitively impaired (CI) Alzheimer's disease (AD) patients and cognitively normal (CN) individuals. Methods Eight subjects (4 biomarker confirmed CI with underlying AD and 4 CN) were scanned on a 3T MRI scanner. The processing pipeline included rigid motion correction and co‐registration of the CEST images with the 3D T 1w images using Advanced Normalization Tools (ANTs). MTR asym maps at 1 ppm, 2 ppm and 3.5 ppm were generated on a voxel‐by‐voxel basis. Each subject's 3D T1w images were processed with FreeSurfer to generate brain region specific ROIs, and the MTR asym values were averaged over the generated ROIs. In addition, a 6‐pool Lorentzian multi‐peak model was fitted to averaged Z‐spectrum data per ROI. Between‐group (CI vs. CN) CEST effects were evaluated using Mann–Whitney U tests. Results Motion correction reduced artifacts and visually improved CEST results. Multiple cortical and white matter ROIs showed differences in MTR asym values between CI and CN groups ( p < 0.05). Overall, the mean MTR asym and Lorentzian amplitudes were lower in the CI than in the CN group. Conclusion Our proposed pipeline enables robust data analysis using either MTR asym or multi‐pool Lorentzian quantification approaches. The results suggest feasibility for detecting CEST differences between CI and CN groups in brain regions previously implicated in AD, motivating future validation in larger cohorts.
Asturias et al. (Sun,) studied this question.