ISMRM24 - Which MRI Contrast for TBI Assessment?

Which MRI Contrast for TBI Assessment?

Weekday Course

ORGANIZERS: Nadya Pyatigorskaya, Yasuhiko Tachibana

Tuesday, 07 May 2024

Summit 1

08:15 - 10:15

Moderators: Manisha Aggarwal & Mary McLean

Skill Level: Basic to Intermediate

Session Number: Tu-01

CME Credit

Session Number: Tu-01

Overview
Experts will discuss how advanced imaging modalities, including Quantitative Susceptibility Mapping (QSM), Diffusion/diffusion tensor imaging (DTI), proton/non-proton MR Spectroscopy (MRS), and PET-MRI, have the potential to provide valuable contrast and insights into TBI microstructural changes, molecular information, and anatomical correlations. These techniques offer promising avenues for improving TBI pathology assessment and understanding, which can lead to more precise and personalized patient care strategies.

Target Audience
Basic scientists and clinicians.

Educational Objectives
As a result of attending this course, participants should be able to:
- Define the significance of diffusion imaging techniques in studying brain microstructure modifications in case of rain damage and their predictive value;
- Describe the place of advanced imaging techniques including Quantitative Susceptibility Mapping (QSM) and MRS in TI imaging at different states and how it offers valuable insights into brain changes for improved patient management; and
- Explore how PET-MRI combines molecular and anatomical information with new advanced tracers allow to enhance our understanding of traumatic injuries.

08:15		DTI & Beyond: Exploring the Microstructure in Brain Trauma View Presentation Video Ante Zhu Keywords: Neuro: Brain, Contrast mechanisms: Diffusion, Contrast mechanisms: Microstructure During a head impact, brain tissues deform due to the force act on the skull. The shearing and stretching of brain tissue structures affect both the function and connectivity of the brain. Diffusion MRI is highly sensitive to structural changes at the microscopic level. This lecture will introduce the microstructure changes associated with traumatic brain injury and how diffusion tensor imaging can probe them. Cutting-edge diffusion-MRI based microstructure imaging techniques and their emerging role in the study of brain damage will also be discussed.
08:45		QSM: Mechanism in Acute/Chronic TBI View Presentation Video Chunlei Liu Keywords: Neuro: Brain, Contrast mechanisms: Electromagnetic tissue properties, Neuro: White matter Quantitative susceptibility mapping (QSM) is a computational technique that calculates voxel-wise magnetic susceptibility values, typically based on the phase images of gradient-echo MRI data. Magnetic susceptibility values of brain tissues can be paramagnetic (i.e. positive) or diamagnetic (i.e. negative) depending on molecular and cellular composition of the tissue. As a result, magnetic susceptibility of brain tissue can be changed by traumatic brain injury (TBI), both in the short term and the long term. This course will discuss the molecular and cellular mechanisms underlying these alterations.
09:15		MRS: Imaging the Metabolic Changes in Brain Trauma View Presentation Video Jae Mo Park Keywords: Neuro: Brain, Contrast mechanisms: Spectroscopy, Contrast mechanisms: Hyperpolarization Hyperpolarized carbon-13 (13C) MRI provides unprecedented in vivo imaging opportunities to assess critical metabolic pathways by imaging both the injected substrate and its metabolic products. This technique with 13C-labeled pyruvate can assess aberrant pyruvate metabolism in the brain by measuring produced 13C-lactate and 13C-bicarbonate in TBI. Studies with hyperpolarized pyruvate demonstrated an acute increase in 13C-lactate production (hyperglycolysis) and a decrease in 13C-bicarbonate production (mitochondrial dysfunction) from a rat TBI model. In parallel, mild TBI patients showed similar observations. These results demonstrate the feasibility and exciting opportunities of hyperpolarized 13C-pyruvate to monitor TBI-associated metabolic changes non-invasively.
09:45		Hybrid PET/MRI: Synergy To Understand Trauma View Presentation Video Damien Galanaud