Multimodal assessment of brain stiffness variation in healthy subjects using magnetic resonance elastography and ultrasound time-harmonic elastography

• Published in: Scientific reports Vol. 14; no. 1; pp. 28580 - 11
• Main Authors: Klemmer Chandía, Stefan, Schattenfroh, Jakob, Brinker, Spencer T., Tzschätzsch, Heiko, Sack, Ingolf, Meyer, Tom
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.11.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166/985; 692/308/2778; 692/700/1421; 692/700/1421/1628; 692/700/1421/1860; 692/700/1421/2025; 692/700/1421/65; Adult; Brain - diagnostic imaging; Brain - physiology; Brain mapping; Correlation analysis; Elasticity Imaging Techniques - methods; Female; Fiducial markers; Healthy Volunteers; Human brain; Humanities and Social Sciences; Humans; Magnetic resonance elastography; Magnetic Resonance Imaging - methods; Male; multidisciplinary; Optical tracking; Science; Science (multidisciplinary); Transtemporal ultrasound time-harmonic elastography; Ultrasonic imaging; Ultrasonography - methods; Ultrasound; Human brain; Magnetic resonance elastography; Optical tracking; Fiducial markers; Transtemporal ultrasound time-harmonic elastography
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-79991-y

Magnetic resonance elastography (MRE) is a noninvasive brain stiffness mapping method. Ultrasound-based transtemporal time-harmonic elastography (THE) is emerging as a cost-effective, fast alternative that has potential applications for bedside monitoring of intracranial pressure. We aim to investigate the accuracy of THE in comparison to MRE performed in the brain. Ten healthy volunteers (25–40 years old) underwent multifrequency MRE (20–35 Hz) and THE (27–56 Hz). Fiducial-marker-based optical tracking of the ultrasound field of view was used to align THE to 3D MRE. THE- and MRE-derived shear wave speed (SWS) was determined as a measure of brain stiffness and averaged within regions of various depths for cross-modality correlation analysis. MRE-measured SWS ranged from 1.0 to 1.3 m/s and was negatively correlated with age (R 2  = 0.44, p  = 0.035). After registration of both modalities, SWS values were linearly correlated (MRE: 1.14 ± 0.08 m/s, THE: 1.13 ± 0.10 m/s; R 2  = 0.62, p  = 0.007). Best agreement between modalities was achieved at depths of 40–60 mm, suggesting this range provides a viable trade-off between ultrasound attenuation and near-field bias. Similar brain regions can be consistently measured with both elastography modalities, despite the regional and individual variations of stiffness. Transtemporal THE yields stiffness values in a range similar to those obtained with more expensive MRE.