ISMRM22 - Contrasts at Low & High Fields: Neuro Function & Metabolism

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

Contrasts at Low & High Fields: Neuro Function & Metabolism

Sunrise Course

ORGANIZERS: Karin Shmueli, Eva-Maria Ratai, Els Fieremans, Mark Does

Wednesday, 11 May 2022

N11 (Breakout B)

08:00 - 09:00

Moderators: José Marques

Skill Level: Basic to Intermediate

Session Number: S-W-07

Session Number: S-W-07

Overview
This course aims to explore the role and effects of static field strength (B0) on contrasts in various applications, particularly for B0 outside the range commonly used for clinical studies.

Target Audience
Clinicians, scientists, and engineers interested is using or developing MRI at particularly high (≥ 7 T) or low (≤ 1 T) fields.

Educational Objectives
As a result of attending this course, participants should be able to:
- Describe the physical principles that influence B0-dependent contrast(s);
- Identify potential clinical and research applications of low and high field MRI; and
- Discuss the trade-offs and limitations associated with low and high field MRI.

	08:00		Promises, limitations, and challenges of MR spectroscopy at ultra-high field View the Presentation Malgorzata Marjanska This presentation will explore the role and the effects of static magnetic field on magnetic resonance spectroscopy. It will focus on promises, limitations and challenges of MR spectroscopy at ultra-high field (≥ 7 T) and will consider physical properties, such as chemical shift, J-coupling, linewidth, T₁ and T₂ relaxation time constants, and technical requirements, such as inhomogeneity of the static magnetic field, inhomogeneous transmit and receive B₁, and limited radiofrequency amplifier power.
	08:30		Functional MRI at Low Magnetic Field Strength View the Presentation Jacco de Zwart There is renewed interest in MRI at low field because of cost, portability, and safety benefits. Functional MRI benefits from high field strength since intrinsic SNR and susceptibility contrast increase with B₀. However, physiological noise limits detection sensitivity at moderate resolution. Furthermore, low-field MR benefits from increased T₂* and decreased T₁. Finally, high field uniformity at low field is essential for transition-band balanced SSFP, an alternative to EPI for BOLD imaging at low field. Preliminary investigation shows that, when accounting for imaging-gradient concomitant field effects, both SSFP and EPI can be readily performed at 0.55 T, EPI showing highest performance.