Meeting Banner
Abstract #3887

Simulation-based amortised inference for analysis of multi-dimensional spectra in combined diffusion-relaxation MRI

Yu Liu1,2, Saad Jbabdi1, Karla L. Miller1, and Amy F.D. Howard1,3
1Wellcome Centre for Integrative Neuroimaging, FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 2Tianjin University, Nankai District, China, 3Imperial College London, London, United Kingdom

Synopsis

Keywords: Microstructure, Simulation/Validation, diffusion-relaxation MRI, parameter evaluation

Motivation: Multi-dimensional diffusion-relaxometry spectra may provide detailed insights into different microenvironments within tissue. However, traditional methods for producing multi-dimensional spectra are unstable and computationally demanding.

Goal(s): To demonstrate the efficacy of simulation-based inference (SBI) to efficiently estimate multi-dimensional spectra in combined diffusion-relaxation MRI.

Approach: Using SBI, we combine a generative signal model with a neural posterior estimator to approximate D-T2 distributions. We test our method on simulated data, including a brain phantom derived from microscopy.

Results: SBI was able to identify multiple, distinct T2-D compartments effectively, even when peaks had small separation. SBI enables parameter inference in seconds, far faster than classical methods.

Impact: This study applied simulation-based inference to multi-dimensional MRI, enabling rapid, precise and robust microstructural tissue characterisation. SBI’s computational speed will particularly benefit high-dimensional data, as the number of parameters grows exponentially with dimensions in classical inference, making conventional methods slow.

How to access this content:

For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.

After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.

After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.

Click here for more information on becoming a member.

Keywords