ISSN# 1545-4428 | Published date: 19 May, 2023
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At-A-Glance Session Detail
   
MR Physics II: From Signals to Images
Weekend Course
ORGANIZERS: Candace Fleischer, Najat Salameh, Ruud van Heeswijk
Saturday, 03 June 2023
718A
13:00 -  16:40
Moderators: Katharina Schregel & Zhiyong Zhang
Skill Level: Basic to Intermediate
Session Number: WE-14
CME Credit

Session Number: WE-14

Overview
This course will provide an introduction to the physics of signal generation across magnetic resonance modalities including structural imaging, spectroscopy, diffusion-weighted imaging, and perfusion-weighted imaging. The course will also introduce and provide an overview of contrast agents, quantitative imaging, and image artifacts. MR Physics II builds upon the introduction to spin physics and signals covered in MR Physics I.

Target Audience
Beginner to intermediate scientist or clinician-scientist, including trainees (students and fellows). While no prior knowledge is required, a basic understanding of nuclear spin, relaxation, and magnetic resonance image types would be beneficial.


Educational Objectives
As a result of attending this course, participants should be able to:
- Describe the source of signal contrast in structural imaging, spectroscopy, and imaging of moving fluids (e.g., diffusion or perfusion weighted imaging);
- Identify the challenges and opportunities for the use of contrast agents and quantitative imaging; and
- Explain sources of image artifacts and how to identify them.

13:00 Generating Signal in Structural Imaging
Puneet Sharma

Keywords: Physics & Engineering: Physics, Image acquisition: Sequences

This educational review discusses the origin and creation of signal for the various techniques commonly used in structural magnetic resonance imaging. The presentation will explore generating signal by exploiting the MR phenomena and relevant tissues properties. Topics will include a description of the RF system, hardware, and their role in signal generation; the MR signal equation and detection; and the important factors to maximize signal strength and quality. In addition, alternate methods for generating MR signal, such as magnetization transfer, will be introduced, along with some future directions, such as deep learning.
13:25 MR Spectroscopy: basic principles
Francesca Branzoli

Keywords: Contrast mechanisms: Spectroscopy

This lecture will focus on the basic principles of MR Spectroscopy: electron shielding, chemical shift and J-coupling will be introduced, together with the basic single-voxel MR Spectroscopy sequences and acquisition steps. The effects of echo-time and field strength on the MR spectrum will also be discussed.  
13:50 The Physics of Imaging Diffusion & Perfusion
Rita Nunes

Keywords: Contrast mechanisms: Diffusion, Contrast mechanisms: Perfusion

This lecture will cover the basic principles of diffusion and perfusion-weighted MRI. The basic diffusion sensitization module will be presented, together with the apparent diffusion coefficient (ADC) and diffusion tensor imaging (DTI) models. Different strategies to measure tissue perfusion will be introduced, relying either on the injection of an external contrast agent as in Dynamic Susceptibility Contrast-MRI (DSC-MRI) and Dynamic Contrast Enhanced-MRI (DCE-MRI) or by using water as an endogenous contrast agent as in Arterial Spin Labelling (ASL). Clinical examples will be briefly presented for both diffusion and perfusion imaging including brain ischemic stroke and tumour imaging.
14:15 Panel Discussion
14:40 Break & Meet the Teachers
15:05 Quantitative Imaging: In Numbers We Trust
Mark Griswold
15:30 Contrast Agents: From Physics to Application
Eliana Gianolio

Keywords: Contrast mechanisms: Contrast agents, Contrast mechanisms: Relaxometry, Contrast mechanisms: CEST & MT

During this lecture the speaker will delve into the physics and chemistry of MR contrast agents and how they enhance image quality, as well as their various applications in clinical practice. Attendees will gain a deeper understanding of the different types of contrast agents used in T1W and T2W MRI, including metal-based agents and iron-oxide nanoparticles, and their advantages and limitations. The lecture will also cover safety concerns on the use of Gadolinium-based CAs and possible alternatives/reduction strategies will be presented. Other classes of CAs beyond Gd and iron-oxide nanoparticles, such as CEST and hyperpolarized agents, will also be introduced.
15:55 Image Artifacts: What Is Real?
Philip Lee

Keywords: Image acquisition: Artefacts

    This session will provide an overview of common image artifacts observed in MRI. Artifacts will be sorted into hardware-related artifacts (in general, ones that can be reproduced in phantoms), and physiological artifacts (ones that can only be observed in vivo). Emphasis will be placed on analyzing raw k-space and coil data to promote an in-depth signal-based understanding. By the end of this session, an attendee should be able to identify what is, and what is not an artifact, and narrow-down candidate causes of the artifact.
16:20 Panel Discussion