ISMRM21 - Multimodal Preclinical Imaging

Multimodal Preclinical Imaging

Weekend Course

ORGANIZERS: Harish Poptani

Sunday, 16 May 2021

Concurrent 3

13:00 - 13:45

Moderators: Christoffer Laustsen & Harish Poptani

Skill Level: Intermediate to Advanced

Session Number: WE-16

Parent Session: Multimodal Preclinical Imaging

Session Number: WE-16

Overview
This session will focus on cutting-edge developments in preclinical imaging. Topics will cover both multiparametric MRI as well as multimodal imaging technologies to demonstrate how preclinical imaging modalities complement each other towards better understanding of the basic mechanisms of disease progression and for monitoring therapeutic response.

The topics will include: a) the role of imaging in evaluating the safety and efficacy of cell therapies including immune/cell therapy of cancer; b) recent advances to assess physiological and metabolic processes, e.g. cardiac, renal or neuro imaging including rs-fMRI, applications; c) multimodal imaging--accounting for differences in resolution or physiological information (e.g. MRI versus PET; MRI and optical imaging or MRI and photo-acoustic imaging); d) development of targeted contrast agents/contrast mechanisms; and e) imaging cell/tissue microstructure with advanced diffusion imaging methods.

Target Audience
Intermediate to advanced MR researchers, including Ph.D. students, postdocs, and fellows interested in learning the latest developments in preclinical imaging and its applications.

The session is aimed at a wider audience and is not organ- or disease-specific and should be of interest to students/physicians and researchers interested in preclinical applications.

Educational Objectives
As a result of attending this course, participants should be able to:
- Review latest contrast mechanisms for tissue metabolism and physiology;
- Evaluate targeted contrast agents for assessing pathology;
- Describe the various diffusion imaging methods for measuring cell size;
- Recognize the value of MR imaging methods to assess the safety and efficacy of regenerative medicine therapies;
- Illustrate complementarity of multi-modal imaging technologies for cell therapies; and
- Demonstrate the utility of artificial intelligence methods in preclinical imaging.

		Multimodal Imaging Watch the Video Mangala Srinivas This is a short introduction to multimodal imaging, covering the combination of MRI with other modalities, such as PET, SPECT and/or fluorescence. We will focus on cell tracking applications in a preclinical setting.
		Imaging & Immune Cell Therapy in Cancer Watch the Video Hai-Ling Cheng Immune cell therapy is an important approach in the broader repertoire of cancer immunotherapy, a new treatment that uses the body’s immune system to fight cancer in a more personalized and effective manner. Injecting immune cells such as chimeric antigen receptor T cells has shown prolonged survival. However, in-vivo cell distribution and survival are often unknown and may underlie why immunotherapy sometimes fails. We will review current methods for tracking immune cells, their limitations, and a potentially larger role for MRI. We will also briefly discuss imaging assessment of tumor response to correctly identify pseudoprogression, an immunotherapy-specific phenotype.
		Targeted Contrast Agents Watch the Video Mark Pagel This presentation will focus on targeted contrast agents for molecular imaging with MRI. Key concepts include * Targeting sensitivity; specificity; selectivity; active and passive mechanisms Heterobivalent binding A “size threshold” for imaging agents Timing for reaching a maximum contrast MRI contrast agents lack sensitivity for detecting cell receptors in less than best-case conditions. MRI can target abundant proteins. Amplification mechanisms can facilitate cell receptor detection. MRI has had more focus on responsive agents. Contrast agents for simultaneous PET/MRI *If molecular imaging can provide more imaging features, MI can revolutionize our clinical radiology workforce.
		Imaging Tissue Microstructure Watch the Video Sungheon Gene Kim Diffusion MRI is a unique imaging modality suitable for probing tissue microstructure. Unlocking the full potential of diffusion MRI for microstructural imaging requires an adequate diffusion encoding method in terms of diffusion time and gradient strength. dMRI Diffusivity is typically interpreted as a rough measure of the cell density and extracellular water fraction. However, diffusivity and other commonly used dMRI metrics remain non-specific markers, because a diffusion measurement at a fixed diffusion time is affected by multiple factors. The complex microstructural features of tumors and the brain can be probed by adequate sampling of the multi-dimensional space of diffusion encoding.
		Imaging in Regenerative Medicine Watch the Video Erik Shapiro This educational lecture will provide a multimodal view of imaging in regenerative medicine. Indeed, the vastness of regenerative medicine requires a complete toolbelt to properly survey the completeness of research and development topics, and clinical methodologies for following treatments. This lecture will survey the uses of multimodal imaging in regenerative medicine, focusing on the benefits of individual imaging methodologies for probing specific research and development questions, and will provide my opinion on how these various imaging technologies might be used clinically.
		Physiological & Metabolic Imaging Watch the Video Kristine Glunde Multimodality molecular imaging applies imaging modalities beyond visualizing anatomy and morphology to include the ability of imaging disease-specific biomolecules and pathways in cancer, cardiovascular disease, and inflammation, among others. Imaging modalities used in physiological and metabolic imaging are computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopic imaging (MRSI), optical imaging, positron emission tomography (PET), single-photon-emission computerized tomography (SPECT), and ultrasound (US).
		Artificial Intelligence & Machine Learning Methods in Preclinical Imaging Simon Walker-Samuel