The Dara Kraitchman Laboratory focuses on non-invasive imaging and minimally invasive treatment of cardiovascular disease. Our laboratory is actively involved in developing new methods to image myocardial function and perfusion using MRI. Current research interests are aimed at determining the optimal timing and method of the administration of mesenchymal stem cells to regenerate infarcted myocardium using non-invasive MR fluoroscopic delivery and imaging. MRI and radiolabeling techniques include novel MR and radiotracer stem cell labeling methods to determine the location, quantity and biodistribution of stem cells after delivery as well as to noninvasively determine the efficacy of these therapies in acute myocardial infarction and peripheral arterial disease. Our other research focuses on the development of new animal models of human disease for noninvasive imaging studies and the development of promising new therapies in clinical trials for companion animals.

Research in the Elizabeth Tucker Lab aims to find treatments that decrease neuroinflammation and improve recovery, as well as to improve morbidity and mortality in patients with infectious neurological diseases. We are currently working with Drs. Sujatha Kannan and Sanjay Jain to study neuroinflammation related to central nervous system tuberculosis – using an animal model to examine the role of neuroinflammation in this disease and how it can differ in developing brains and adult brains. Our team also is working with Dr. Jain to study noninvasive imaging techniques for use in monitoring disease progression and evaluating treatment responses.

Research in the Wojciech Zbijewski Lab — a component of the Imaging for Surgery, Therapy and Radiology (I-STAR) Lab — focuses on system modeling techniques to optimize the x-ray CT imaging chain. We’re specifically interested in: 1) using numerical models to improve the task-based optimization of image quality; 2) exploring advanced modeling of physics in statistical reconstruction; 3) using accelerated Monte Carlo methods in CT imaging; and 4) conducting experimental validation of such approaches and applying them to the development of new imaging methods.

The Lima Lab’s research is concentrated on the development and application of imaging and technology to address scientific and clinical problems involving the heart and vascular system. Specifically, our research is focused on developing magnetic resonance imaging (MRI) contrast techniques to investigate microvascular function in patients and experimental animals with myocardial infarction; functional reserve secondary to dobutamine stimulation and myocardial viability assessed by sodium imaging; and cardiac MRI and computed tomography (CT) program development of techniques to characterize atherosclerosis in humans with cardiovascular or cerebrovascular disease. Current projects include: • The Coronary Artery Risk Development in Young Adults (CARDIA) Study • The MESA (Multi-Ethnic Study of Atherosclerosis) Study • The Coronary Artery Evaluation using 64-row Multidetector Computed Tomography Angiography (CORE64) Study Joao Lima, MD, is a professor of medicine, radiology and epidemiology at the Johns Hopkins School of Medicine.

The Glunde lab is within the Division of Cancer Imaging Research in the Department of Radiology and Radiological Science. The lab is developing mass spectrometry imaging as part of multimodal molecular imaging workflows to image and elucidate hypoxia-driven signaling pathways in breast cancer. They are working to further unravel the molecular basis of the aberrant choline phospholipid metabolism in cancer. The Glunde lab is developing novel optical imaging agents for multi-scale molecular imaging of lysosomes in breast tumors and discovering structural changes in Collagen I matrices and their role in breast cancer and metastasis.

The Kristina Nielsen Laboratory investigates neural circuits in the visual cortex that are responsible for encoding objects to understand how the visual system performs object recognition. We aim to reveal the fine-scale organization of neural circuits, with an emphasis on higher-level visual areas. We use two-photon microscopy to perform high-resolution functional imaging of visual areas in the non-human primate. We also investigate how the function of higher visual areas changes over the course of brain development in ferrets, by measuring the activity of single neurons in these areas, as well as determining the animal's visual capabilities at various developmental stages. In both types of investigations, we also rely on detailed anatomical techniques to precisely observe how the function of neuronal circuits is related to their structure.

The O’Rourke Lab uses an integrated approach to study the biophysics and physiology of cardiac cells in normal and diseased states. Research in our lab has incorporated mitochondrial energetics, Ca2+ dynamics, and electrophysiology to provide tools for studying how defective function of one component of the cell can lead to catastrophic effects on whole cell and whole organ function. By understanding the links between Ca2+, electrical excitability and energy production, we hope to understand the cellular basis of cardiac arrhythmias, ischemia-reperfusion injury, and sudden death. We use state-of-the-art techniques, including single-channel and whole-cell patch clamp, microfluorimetry, conventional and two-photon fluorescence imaging, and molecular biology to study the structure and function of single proteins to the intact muscle. Experimental results are compared with simulations of computational models in order to understand the findings in the context of the system as a whole. Ongoing studies in our lab are focused on identifying the specific molecular targets modified by oxidative or ischemic stress and how they affect mitochondrial and whole heart function. The motivation for all of the work is to understand • how the molecular details of the heart cell work together to maintain function and • how the synchronization of the parts can go wrong Rational strategies can then be devised to correct dysfunction during the progression of disease through a comprehensive understanding of basic mechanisms. Brian O’Rourke, PhD, is a professor in the Division of Cardiology and Vice Chair of Basic and Translational Research, Department of Medicine, at the Johns Hopkins University.

We investigate the brain networks and neurotransmitters involved in symptoms of movement disorders, such as Parkinson's disease, and the mechanisms by which modulating these networks through electrical stimulation affects these symptoms. We are particularly interested in the mechanisms through which neuromodulation therapies like deep brain stimulation affect non-motor brain functions, such as cognitive function and mood. We use imaging of specific neurotransmitters, such as acetylcholine and dopamine, to understand the changes in brain chemistry associated with the clinical effects of deep brain stimulation and to predict which patients are likely to have changes in non-motor symptoms following DBS. Through collaborations with our neurosurgery colleagues, we explore brain function by making recordings during DBS surgery during motor and non-motor tasks. Dr. Mills collaborates with researchers in the Department of Neurosurgery, the Division of Geriatric and Neuropsychiatry in the Department of Psychiatry and Behavioral Sciences and in the Division of Nuclear Medicine within the Department of Radiology to translate neuroimaging and neurophysiology findings into clinical applications.

The Hey-Kyoung Lee Lab is interested in exploring the cellular and molecular changes that happen at synapses to allow memory storage. We use various techniques, including electrophysiological recording, biochemical and molecular analysis, and imaging, to understand the cellular and molecular changes that happen during synaptic plasticity. Currently, we are examining the molecular and cellular mechanisms of global homeostatic synaptic plasticity using sensory cortices as model systems. In particular, we found that loss of vision elicits global changes in excitatory synaptic transmission in the primary visual cortex. Vision loss also triggers specific synaptic changes in other primary sensory cortices, which we postulate underlies sensory compensation in the blind. One of our main research goals is to understand the mechanisms underlying such cross-modal synaptic plasticity. We are also interested in elucidating the events that occur in diseased brains. In collaboration with other researchers, we are analyzing various mouse models of Alzheimer's disease, especially focusing on the possible alterations in synaptic plasticity mechanisms.

The Penet lab is within the Division of Cancer Imaging Research in the Department of Radiology and Radiological Science. The lab research focuses on using multimodal imaging techniques to better understand the microenvironment and improve cancer early detection, especially in ovarian cancer. By combining MRI, MRS and optical imaging, we are studying the tumor microenvironment to understand the role of hypoxia, tumor vascularization, macromolecular transport and tumor metabolism in tumor progression, metastasis and ascites formation in orthotopic models of cancer. We also are studying the role of tumor-associated macrophages in tumor progression.