ISMRM25 - Contrast Mechanism: Modelling from the Ground Up

ISMRM & ISMRT Annual Meeting & Exhibition • 10-15 May 2025 • Honolulu, Hawai'i

Contrast Mechanism: Modelling from the Ground Up

Weekend Course

ORGANIZERS: Weitian Chen, Flavio Dell'Acqua, Shaihan Malik, Marco Palombo, Cristian Tejos

Saturday, 10 May 2025

316C

13:00 - 16:50

Moderators:
All Sections: Elizabeth Powell & Dan Wu

Skill Level: Intermediate to Advanced

Session Number: WE-12

CME Credit

Session Number: WE-12

Overview
How do you model? Molecular dynamics and microstructure: connections between relaxation, diffusion, MT. Underlying physics and biology.

Target Audience
Intermediate or advanced researchers or clinicians, including trainees (students and fellows) who wish to learn about the physical models behind MRI contrast mechanisms.

Educational Objectives
As a result of attending this course, participants should be able to:
• Describe physical origins of relaxation, diffusion, exchange and susceptibility contrasts;
• Construct analytic and numerical models for these contrasts; and
• Discuss fundamental connections between these contrasts and how to create unified models.

Part I
13:00		Physics of Relaxation View Presentation Video Dmitriy Yablonskiy Impact: MRI signal relaxation properties (T1, T2, T2*) play a pivotal role in revealing tissue characteristics. This presentation explores the key mechanisms underlying water proton interactions with cellular macromolecules and their contribution to MRI contrast in healthy and diseased tissues.
13:25		Physics of Diffusion View Presentation Video Rafael Henriques Impact: This talk introduces key diffusion physics concepts, including random walks, diffusion propagator, Gaussian and non-Gaussian diffusion, and time-dependent effects, providing a foundation for understanding biophysical models and advanced diffusion MRI techniques.
13:50		Physics of MT/Exchange View Presentation Video Andreea Hertanu Impact: This lecture introduces magnetization transfer principles, starting with the binary spin-bath model and the Bloch-McConnell framework. It covers key factors like proton lineshapes, on-resonance effects and advanced strategies for modeling MT signals.
14:15		Physics of Susceptibility View Presentation Video Emma Biondetti Impact: Description of magnetic susceptibility Magnetic susceptibility of haem and non-haem iron, and myelin Field perturbation generated by a magnetic susceptibility distribution
14:40		Break & Meet the Teachers
Part II
15:10		Microstructural Models & Analysis of Diffusion View Presentation Video Marco Pizzolato Impact: Diffusion MRI modeling varies in assumptions and approximations but provides key insights into tissue properties. This talk explores increasing complexity in microstructure modeling, covering key advancements, theoretical insights, and future challenges in the field.
15:35		Biophysical Models & Analysis of Relaxation & Susceptibility View Presentation Video Anders Sandgaard Impact: Estimating tissue magnetic susceptibility with MRI requires biophysical modeling of the microstructure and magnetic properties. This lecture covers biophysical susceptibility models using MRI signal phase and transverse relaxation, which offer insight into tissue chemical composition
16:00		Unifying Microstructural Models (Diffusion, Relaxation & Exchange) Dmitry Novikov
16:25		From the Top Down: Inferring Parameters from Complex Models Eleftherios Garyfallidis