7 tricks for 7 T CEST: Improving the reproducibility of multipool evaluation provides insights into the effects of age and the early stages of Parkinson's disease
Mennecke A, Khakzar KM, German A, Herz K, Fabian M, Liebert A, Blümcke I, Kasper B, Nagel AM, Laun FB, Schmidt M, Winkler J, Dörfler A, Zaiß M (2022)
Publication Type: Journal article
Publication year: 2022
Journal
DOI: 10.1002/nbm.4717
Abstract
The objective of the current study was to optimize the postprocessing pipeline of 7 T chemical exchange saturation transfer (CEST) imaging for reproducibility and to prove this optimization for the detection of age differences and differences between patients with Parkinson's disease versus normal subjects. The following 7 T CEST MRI experiments were analyzed: repeated measurements of a healthy subject, subjects of two age cohorts (14 older, seven younger subjects), and measurements of 12 patients with Parkinson's disease. A slab-selective, (Formula presented.) -homogeneous parallel transmit protocol was used. The postprocessing, consisting of motion correction, smoothing, (Formula presented.) -correction, normalization, denoising, (Formula presented.) -correction and Lorentzian fitting, was optimized regarding the intrasubject and intersubject coefficient of variation (CoV) of the amplitudes of the amide pool and the aliphatic relayed nuclear Overhauser effect (rNOE) pool within the brain. Seven “tricks” for postprocessing accomplished an improvement of the mean voxel CoV of the amide pool and the aliphatic rNOE pool amplitudes of less than 5% and 3%, respectively. These postprocessing steps are: motion correction with interpolation of the motion of low-signal offsets (1) using the amide pool frequency offset image as reference (2), normalization of the Z-spectrum using the outermost saturated measurements (3), (Formula presented.) correction of the Z-spectrum with moderate spline smoothing (4), denoising using principal component analysis preserving the 11 highest intensity components (5), (Formula presented.) correction using a linear fit (6) and Lorentzian fitting using the five-pool fit model (7). With the optimized postprocessing pipeline, a significant age effect in the amide pool can be detected. Additionally, for the first time, an aliphatic rNOE contrast between subjects with Parkinson's disease and age-matched healthy controls in the substantia nigra is detected. We propose an optimized postprocessing pipeline for CEST multipool evaluation. It is shown that by the use of these seven “tricks”, the reproducibility and, thus, the statistical power of a CEST measurement, can be greatly improved and subtle changes can be detected.
Authors with CRIS profile
Angelika Mennecke
Department of Neuroradiology
Alexander German
Professur für quantitative MR-Bildgebung (Heisenberg-Professur)
Moritz Fabian
Department of Neuroradiology
Andrzej Liebert
Institute of Radiology
Ingmar Blümcke
Lehrstuhl für Neuropathologie
Burkhard Kasper
Medizinische Fakultät
Armin Michael Nagel
Professur für metabolische und funktionelle MR-Bildgebung
Frederik Bernd Laun
Professur für quantitative MR-Bildgebung (Heisenberg-Professur)
Manuel Schmidt
Department of Neuroradiology
Jürgen Winkler
Professur für Molekulare Neurologie
Arnd Dörfler
Department of Neuroradiology
Moritz Zaiß
Professur für Multimodale Bildgebung in der klinischen Forschung
Involved external institutions
Germany (DE)How to cite
APA:
Mennecke, A., Khakzar, K.M., German, A., Herz, K., Fabian, M., Liebert, A.,... Zaiß, M. (2022). 7 tricks for 7 T CEST: Improving the reproducibility of multipool evaluation provides insights into the effects of age and the early stages of Parkinson's disease. NMR in Biomedicine. https://dx.doi.org/10.1002/nbm.4717
MLA:
Mennecke, Angelika, et al. "7 tricks for 7 T CEST: Improving the reproducibility of multipool evaluation provides insights into the effects of age and the early stages of Parkinson's disease." NMR in Biomedicine (2022).
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