Virtual Meetings

Artificial intelligence is increasingly being used in perfusion imaging applications and has the potential to achieve huge improvements in image quality, scan speed and the accuracy of automated image processing. However, there are also many challenges, including: generalisability across scanners, protocols and patient cohorts; access to sufficient training data; hallucinations within reconstructed images and the validation of performance metrics. In this session, we will showcase some novel AI applications in both non-contrast and contrast-enhanced perfusion imaging in the brain and body, outline some common pitfalls in AI-based image reconstruction, and discuss future opportunities and challenges in this field with our expert panel.

This virtual meeting organized by the MRI of Neuromodulation Study Group highlights two cutting-edge technologies for MRI of neuromodulation: transcranial-focused ultrasound (FUS) and robotic transcranial magnetic stimulation (TMS) with concurrent fMRI and EEG. Li Min Chen, M.D., Ph.D., will present her latest work on using low-intensity FUS modulation of the low-frequency local field potentials in the thalamus and insular cortex and single-unit spiking in the ventroposterior lateral (VPL) nucleus of macaque monkey, with concurrently evoked BOLD fMRI signals. Second, Chunlei Liu, Ph.D., will present his work on developing a robotic TMS system with concurrent fMRI and EEG recording to map brain network dynamics, with potential neuroscientific applications in sleep.

Quantitative BOLD and calibrated fMRI provide complementary approaches for linking functional MRI signals to cerebral oxygen metabolism and neurovascular physiology. This virtual meeting will explore the principles, methodological foundations, and current challenges of these approaches, using the recent Nature Neuroscience paper by Epp, et.al., “BOLD Signal Changes Can Oppose Oxygen Metabolism Across the Human Cortex," as a common starting point or a broader discussion of quantitative BOLD.

The meeting will begin with an educational overview of quantitative BOLD and calibrated fMRI, including the rationale underlying each approach, their methodological implementations, and their respective advantages and limitations. This will be followed by a presentation of recent multiparametric BOLD findings and analyses addressing the relationship between BOLD and metabolic responses. Two complementary perspectives will then examine the complexity of BOLD contrast mechanisms, the interpretation of negative BOLD responses and metabolic estimates, and the potential impact of model assumptions, measurement choices, and uncertainty on voxel-wise BOLD–CMRO₂ relationships. The meeting will conclude with an open discussion and Q&A, bringing together different perspectives on the physiological interpretation of quantitative fMRI signals, methodological challenges, and future directions for the field.

Recent progress in MASH has highlighted the growing potential of quantitative MRI biomarkers to inform regulatory decision-making and accelerate drug development. Drawing on the work of the FNIH NIMBLE consortium, this session will explore the evidentiary framework required for regulatory acceptance of imaging biomarkers as Reasonably Likely Surrogate Endpoints (RLSEs), including biological plausibility, analytical validation, and clinical evidence. This session will focus on MRI-based alternatives to liver biopsy, share the progress that's made, and reflect on lessons learned that may be applicable to other therapeutic areas.

Molecular MRI aims to improve biological specificity by generating imaging signals that report on defined molecular and cellular events. This virtual meeting will present two emerging molecular MRI approaches for studying brain function. Yi Zhang, Ph.D., will describe CEST MRI combined with a dynamic signal model that accounts for BOLD contributions to generate glutamate-weighted activation maps during stimulation. Robert Ohlendorf, Ph.D., will describe photosensitized vasculature that acts as a biological transducer, converting bioluminescent reporter emission into localized hemodynamic signals detectable by MRI. Together, the metabolite-sensitive imaging and engineered vascular reporter approaches demonstrate how molecular MRI can link neurochemistry and cellular events to brain-scale imaging. The speakers will discuss the underlying principles, technical challenges, validation requirements, and future applications of these methods.

How did we end up with the magnetic field strengths we currently have? How did the physics and engineering of superconducting magnets impact the growth of the field? Where might this technology lead us in the future? Six scientists and engineers who played key roles in the development of these systems will discuss how we got here and where we might be going in the context of three key decision points: 1.5T vs. 2T, 3T vs. 4T, and 7T vs. 8T or 9.4T. We will discuss how the technology has evolved over the past 40 years and how the field has responded to needs for lower cryogen and power consumption.

Speakers:

For this webinar, the first talk highlights the best strategies for MRI safety across different magnetic field strengths from low field to high field including safety around devices, an emerging consideration in paediatric patients. The second talk focuses on MR hardware considerations for image acquisition unique to pediatrics from fetal to perinatal to infant, young child, and adolescent, and ways to optimize signal-to-noise, contrast-to-noise, and artifact reduction. Faster acquisitions for feed and sleep techniques and to reduce the need for general anesthesia are explored.