Techniques for Studying Blood Flow

TOPICAL COLLECTIONS

Guest Editors

Nilesh Ghugre

Sunnybrook Research Institute

Dr. Nilesh Ghugre is a Scientist in the Schulich Heart Program at Sunnybrook Research Institute (SRI) and an Assistant Professor in the Department of Medical Biophysics at the University of Toronto. He received his Master's and PhD in Biomedical Engineering from the University of Southern California, Los Angeles, USA. His research utilizes advanced cardiac MRI biomarkers to characterize the post-acute myocardial infarct (or heart attack) remodeling process and determine efficacy of novel therapeutic interventions to prevent heart failure. To this end, he is involved in exploring novel experimental models that represent clinical manifestation of heart disease and new therapeutic targets that can alleviate injury in the heart. His lab is developing quantitative MRI tools (T1, T2, T2*, DTI) to probe cardiac pathophysiology parameters, including viability, edema, inflammation, hemorrhage, and microvascular integrity and function/structure. More recently, he has been advancing image-guidance technologies for cardiac regenerative medicine. The aim is to develop image-based technologies that will facilitate accurate and minimally invasive cell delivery to the injured region of the heart, and visualize delivery success, tissue response, and outcomes, all within the same framework. His lab projects are supported by the Heart and Stroke Foundation (HSF), Natural Sciences and Engineering Research Council (NSERC), New Frontiers in Research Fund – Exploration (NFRF-E), and the University of Toronto Medicine by Design (MbD) program.

Jill Weyers

Sunnybrook Research Institute

Dr. Jill Weyers completed her PhD in Developmental Biology and Genetics at Johns Hopkins University. There, she examined the genetic mechanisms of organogenesis, with a focus on cellular movements and interactions. She then did postdoctoral research in cardiovascular regenerative medicine with Drs. Chuck Murry and Bill Mahoney at the University of Washington where she investigated the use of stem cells to repair and revascularize infarcted hearts. This is also where she developed an interest in cardiovascular imaging technologies, which have been a prominent theme of her career ever since. She has subsequently gained expertise in multiple imaging technologies, all toward the goal of better visualizing the heart, vasculature, and the dynamics of blood flow, including micro-CT, echocardiography, optical coherence tomography, optical projection tomography, intravascular ultrasound, and most recently, cardiac MRI (CMR). She is now a Research Associate in the Cardiovascular Imaging group at Sunnybrook Research Institute in Toronto, working with Drs. Graham Wright and Nilesh Ghugre. Her current research focus uses quantitative CMR methods to visualize the hemorrhage, inflammation, and microvascular dysfunction that accompany myocardial injury, with the goal of developing therapies to limit myocardial damage and enhance recovery in heart attack victims.

Collection Overview

All tissues and organs require a steady supply of blood to stay oxygenated and nourished. However, the amount of flow differs from tissue to tissue, as well as with changes in tissue function, during growth or atrophy, and in various states of disease or damage. Understanding these differing flow requirements and the tissue’s response to changes in flow can be an important step toward fully understanding tissue function, as well as disease state and progression. Observing and understanding blood flow is also important for the success of various treatments. For example, some therapies aim to increase angio- and arteriogenesis, the success of which would ideally be measured through increases in blood flow, not just the presence of new vessels. In addition, sufficient blood flow must be established for the optimal functionality of engineered constructs, tissue implants, injected cells or hydrogels, and other regenerative medicine therapies.

Despite the importance of understanding organ blood flow, it is often overlooked or substituted with histological evidence of vessels and perfusion (e.g., the presence of RBCs). It may not be clear what methods are available or what techniques would be best for differing contexts and experimental goals, and there may be a lack of description of precise protocols and materials needed for execution. Furthermore, blood flow techniques share commonalities across organs, but are often overlooked due to lack of information on translation. With this methods collection we aim to pull together a variety of techniques used to study blood flow that are widely applicable to different organs, model systems, and imaging modalities. They include, but are not limited to, ways to visualize flow, quantify flow, determine changes in flow, and manipulate and perturb flow to determine tissue response.