Magnetic resonance elastography in a nutshell: Tomographic imaging of soft tissue viscoelasticity for detecting and staging disease with a focus on inflammation

• Published in: Progress in nuclear magnetic resonance spectroscopy 2024-11, Vol.144-145, p.1-14
• Main Authors: Meyer, Tom, Castelein, Johannes, Schattenfroh, Jakob, Sophie Morr, Anna, Vieira da Silva, Rafaela, Tzschätzsch, Heiko, Reiter, Rolf, Guo, Jing, Sack, Ingolf
• Format: Article
• Language: English
• Subjects: Animals; Brain; Elasticity; Elasticity Imaging Techniques - methods; Fibrosis; Humans; Inflammation; Inflammation - diagnostic imaging; Liver; Magnetic Resonance Elastography; Magnetic Resonance Imaging - methods; MRE; Viscosity
• ISSN: 0079-6565; 1873-3301
• DOI: 10.1016/j.pnmrs.2024.05.002

[Display omitted] •This review article presents the key technical aspects of magnetic resonance elastography (MRE) in a compact and concise manner.•It focuses on the detection of the mechanical hallmarks of inflammation − a blind spot in medical imaging today.•Based on the literature, it provides a thorough understanding of the mechanisms that lead to marked changes in the biomechanical properties of soft tissues during disease progression, from early inflammation to chronic remodeling.•JG and IS hold patents and shares in time harmonic elastography applications and devices. The other authors do not declare interests and relationships with respect to the matter of the article. Magnetic resonance elastography (MRE) is an emerging clinical imaging modality for characterizing the viscoelastic properties of soft biological tissues. MRE shows great promise in the noninvasive diagnosis of various diseases, especially those associated with soft tissue changes involving the extracellular matrix, cell density, or fluid turnover including altered blood perfusion – all hallmarks of inflammation from early events to cancer development. This review covers the fundamental principles of measuring tissue viscoelasticity by MRE, which are based on the stimulation and encoding of shear waves and their conversion into parameter maps of mechanical properties by inverse problem solutions of the wave equation. Technical challenges posed by real-world biological tissue properties such as viscosity, heterogeneity, anisotropy, and nonlinear elastic behavior of tissues are discussed. Applications of MRE measurement in both humans and animal models are presented, with emphasis on the detection, characterization, and staging of diseases related to the cascade of biomechanical property changes from early to chronic inflammation in the liver and brain. Overall, MRE provides valuable insights into the biophysics of soft tissues for imaging-based detection and staging of inflammation-associated tissue changes.