Fractional Anisotropy as a Surrogate Marker of Brain Mechanics

Rampp S, Budday S, Reiter N, Tueni N, Hinrichsen J, Paulsen F, Schnell O, Flé G, Laun FB, Dörfler A (2026)

Publication Status: In review

Publication Type: Unpublished / Preprint

Future Publication Type: Journal article

Publication year: 2026

Original Authors: Stefan Rampp, Silvia Budday, Nina Reiter, Nicole Tueni, Jan Hinrichsen, Lars Bräuer, Friedrich Paulsen, Oliver Schnell, Guillaume Flé, Frederik Bernd Laun, Arnd Doerfler

DOI: 10.64898/2026.04.13.717439

Abstract

Understanding the mechanical properties of brain tissue may provide crucial insights into brain development, injury, disease and surgical planning. Conventionally, these properties are measured ex vivo or in vivo during surgical procedures, while non-invasive in vivo alternatives are sparse. This study investigates whether fractional anisotropy (FA) derived from diffusion-weighted magnetic resonance imaging can serve as a surrogate marker for brain tissue stiffness in healthy human brains.

MRI data were collected from three body donor brains, 28 healthy adults, and a publicly available independent dataset of 26 adults. FA values were compared with mechanical properties from ex vivo mechanical testing of brain tissue.

Statistical analysis revealed a strong negative correlation between FA and the mechanical response for small strains expressed as shear modulus of a one-term hyperelastic Ogden model, indicating that higher FA values are associated with lower tissue stiffness. The nonlinearity parameter alpha exhibited a qualitatively similar, but considerably weaker correlation with FA. These findings were consistent across datasets.

The findings suggest that FA can be a robust, non-invasive marker for estimating mechanical properties of brain tissue, with potential applications in clinical diagnosis and computational modeling of brain mechanics and the study of brain development. Further research is needed to clarify the relationship in lesional tissues and to optimize clinical utility.

Authors with CRIS profile

Stefan Rampp Department of Neurosurgery Silvia Budday Lehrstuhl für Kontinuumsmechanik (Schwerpunkt Biomechanik) Nina Reiter Lehrstuhl für Kontinuumsmechanik (Schwerpunkt Biomechanik) Nicole Tueni Lehrstuhl für Kontinuumsmechanik (Schwerpunkt Biomechanik) Jan Hinrichsen Lehrstuhl für Technische Mechanik (LTM) Friedrich Paulsen Lehrstuhl für Funktionelle und Klinische Anatomie Oliver Schnell Lehrstuhl für Neurochirurgie Guillaume Flé Institute of Radiology Frederik Bernd Laun Institute of Radiology Arnd Dörfler Lehrstuhl für Neuroradiologie

Additional Organisation(s)

Sonderforschungsbereich 1540/1 - Erforschung der Mechanik des Gehirns (EBM): Verständnis, Engineering und Nutzung mechanischer Eigenschaften und Signale in der Entwicklung, Physiologie und Pathologie des zentralen Nervensystems

How to cite

APA:

Rampp, S., Budday, S., Reiter, N., Tueni, N., Hinrichsen, J., Paulsen, F.,... Dörfler, A. (2026). Fractional Anisotropy as a Surrogate Marker of Brain Mechanics. (Unpublished, In review).

MLA:

Rampp, Stefan, et al. Fractional Anisotropy as a Surrogate Marker of Brain Mechanics. Unpublished, In review. 2026.

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