Scientific Reports (Oct 2023)

Multi-model sequential analysis of MRI data for microstructure prediction in heterogeneous tissue

  • Francisco E. Enríquez-Mier-y-Terán,
  • Aritrick Chatterjee,
  • Tatjana Antic,
  • Aytekin Oto,
  • Gregory Karczmar,
  • Roger Bourne

DOI
https://doi.org/10.1038/s41598-023-43329-x
Journal volume & issue
Vol. 13, no. 1
pp. 1 – 14

Abstract

Read online

Abstract We propose a general method for combining multiple models to predict tissue microstructure, with an exemplar using in vivo diffusion-relaxation MRI data. The proposed method obviates the need to select a single ’optimum’ structure model for data analysis in heterogeneous tissues where the best model varies according to local environment. We break signal interpretation into a three-stage sequence: (1) application of multiple semi-phenomenological models to predict the physical properties of tissue water pools contributing to the observed signal; (2) from each Stage-1 semi-phenomenological model, application of a tissue microstructure model to predict the relative volumes of tissue structure components that make up each water pool; and (3) aggregation of the predictions of tissue structure, with weightings based on model likelihood and fractional volumes of the water pools from Stage-1. The multiple model approach is expected to reduce prediction variance in tissue regions where a complex model is overparameterised, and bias where a model is underparameterised. The separation of signal characterisation (Stage-1) from biological assignment (Stage-2) enables alternative biological interpretations of the observed physical properties of the system, by application of different tissue structure models. The proposed method is exemplified with human prostate diffusion-relaxation MRI data, but has potential application to a wide range of analyses where a single model may not be optimal throughout the sampled domain.