ISMRM22 - Physics for Clinicians II

Joint Annual Meeting ISMRM-ESMRMB & ISMRT 31st Annual Meeting • 07-12 May 2022 • London, UK

Physics for Clinicians II

Weekday Course

ORGANIZERS: Ashley Harris, Adrienne Campbell-Washburn, Philipp Ehses

Tuesday, 10 May 2022

N11 (Breakout B)

09:15 - 11:15

Moderators:
Physics for Clinicians II.A: Catherine Morgan
Physics for Clinicians II.B: Rebecca Williams

Skill Level: Basic

Session Number: Tu-02

Session Number: Tu-02

Overview
This session (and the associated session MR Physics for Clinicians Part 1) will discuss the physics of magnetic resonance from first principles to applications. The presentations will focus on concepts and will not be mathematical, thus targeting clinicians and physicists new to the field. It will provide a basic and comprehensive review of signal generation, encoding, relaxation, and image contrast.

Target Audience
This course is designed for the clinician who aims to understand the principles of MR imaging. No prior knowledge is necessary, but those with some familiarity or experience will also benefit. Interested attendees may include radiologists and clinicians who are relatively new to MRI, or those more experienced who want a refresher, and physicists/engineers who are looking for an introduction to MRI.

Educational Objectives
As a result of attending this course, participants should be able to:
- Describe the fundamental principles of MR imaging, including spin magnetization and precession;
- Describe sources of image contrast;
- Define the differences between signal weighting and quantitative imaging (e.g., contrast T1-weighted images with T1- maps);
- Interpret the basics of a pulse sequence and pulse sequence parameters and compare differences;
- Summarize basic concepts for more advanced methods and acquisitions;
- Explain the fundamentals of image reconstruction methods including parallel imaging and compressed sensing;
- Compare terminology across vendors, including vendor-specific terms and definitions that vary between platforms;
- Assess artifacts that arise from the patient such as physiological noise and motion and bulk motion and some possible solutions; and
- Recall insight from a real-world example on the translation of novel MR approaches to their use in clinic.

	Physics for Clinicians II.A
09:15		Image Reconstruction for Clinicians View the Presentation Katherine Wright This presentation will review basic and advanced MR image reconstruction methods. Raw data in MRI are not collected directly in the image domain. They are collected in k-space, where each data point contains information about the entire object being imaged. k-space data must be transformed into an image, a process called image reconstruction, which is most often performed by applying the Fourier Transform. We will review properties of k-space and the relationship between k-space and image domains, as these are key to understanding most reconstruction methods. Next, we will review several reconstruction methods that are used on clinical MRI scanners.
09:45		Techniques & Terminology Across Vendors View the Presentation Matthias Gunther MRI is the medical imaging modality with by far the largest diversity of “imaging modes” (aka MR sequences). There seems to be the habit in the MR community to compete in terms of fantasy when it comes to sequence naming. Over the past, this has led to a huge variety of different acronym denoting MR sequence, which are closely related, but still carry different names. Very minor changes seem to justify the creation of new acronyms. This makes the field of MR sequences challenging. Fortunately, dictionaries of acronyms exist to guide one through this jungle (for links see reference section).
	Physics for Clinicians II.B
10:15		Addressing Patient-Related Artifacts: Implants & Motion View the Presentation Ives Levesque This lecture will review the manifestations, fundamental physics, and mitigation strategies of patient-related artifacts, namely those that arise from motion and from implants. In the first portion, artifacts arising from implants will be addressed, focusing on susceptibility induced signal dropout, image distortion, and signal displacement. In the second portion, we will turn to the broad category of motion-related artifacts to explore how various sources of motion corrupt MR images. Possible “confound” artifacts will be included. Approaches for mitigation of these artifacts will be discussed, emphasizing the practical tradeoffs and the latest solutions proposed in research.
10:45		Translating New Methods to the Clinic: A Practical Guide View the Presentation Jamie MacKay This session will outline the key practical steps in translating a novel MRI method into the clinic. The challenges at each step will be discussed, with an emphasis on the important difference between clinical validation and demonstration of clinical utility. My talk will be illustrated by examples of MRI methods which have been successful & unsuccessful at each stage of the translation process. In particular, we will consider whole-body MRI and quantitative cartilage MRI as exemplars of MRI methods which have been more or less successful in translation to the clinic.