Assistant Professor, Biological Sciences
Carnegie Mellon University

Phone: (412) 268-5105
Fax: (412) 268-7083
Email: eta@andrew.cmu.edu

Ph.D., University of California

Research Interests

My research centers on advancing the state-of-the-art of magnetic resonance imaging (MRI) and using these techniques to visualize development, connectivity, function, and pathology of the vertebrate nervous system. Extremely-high resolution MRI, or magnetic resonance microscopy (MRM), is an emerging technique that can observe the inner workings of intact living animals in three-dimensions at near-cellular resolution. Tissue morphological changes, progression of disease states, and biochemical changes may all be visualized with MRM. Small animal models of human development and disease are often the subject, and these capabilities make MRM an ideal complement to optical microscopy.

Currently my lab focuses on understanding early events associated with the onset of autoimmune disease in the central nervous system (CNS). For these studies, we employ a prototypical animal disease model called experimental allergic encephalomyelitis (EAE). Many aspects of EAE mimic the human disease multiple sclerosis. Both diseases are characterized by the presence of lymphocyte infiltrates in white matter of the CNS. Also, demyelination is often observed. Our emphasis is understanding the mechanisms of the early lymphocyte entry into the CNS. Towards this goal, MRM is used to conduct in vivo longitudinal investigations using numerous imaging modalities. We employ anatomical image analyses, quantitative biophysical measurements, intra-cellular contrast reagents, and functional imaging. The studies are conducted at the Pittsburgh NMR Center for Biomedical Research.

In parallel with this project, we are working on advancing MRM technology. We are devising new strategies for improving the sensitivity and resolution of MRM using cryogenically-cooled detection hardware. Also, in collaboration with the Computer Graphics Group at Brown University, we are developing novel software visualization tools for three-dimensional rendering of MR images.

Recent Publications

• Ahrens ET, Morel PA:  In vivo imaging of automimmune disease in model systems.  Curr Top Dev Biol 70: 215-238, 2005.
• Ahrens ET, Flores R, Xu HY, Morel PA:  In vivo imaging platform for tracking immunotherapeutic cells.  Nat Biotech 23: 983-987, 2005.

• Genove G, DeMarco U, Xu H, Goins WF, Ahrens ET: A novel transgene reporter for in vivo magnetic resonance imaging:  Nat Med 11: 450-454, 2005.
• Kaufman JA, Ahrens ET, Laidlaw DH, Zhang S, Allman JM:  Morphometric analysis of the aye-aye brain (Daubentonia madagascariensis primates:  Prosimii) using fiber histology, structural MRI, and diffusion-tensor imaging (DTI).  Anat Rec 287A: 1026-1037, 2005.
• Koshibu K, Ahrens ET, Levitt P:  Postpubertal sex differentiation of forebrain structures and functions depend on transforming growth factor.  J Neurosci 25: 3870-3880, 2005.
• Ahrens ET, Srinivas M, Capuano S, Simhan HN, Schatten GP:  MRI of embryonic and fetal development in model systems.  Methods Mol Med 124: 87-101, 2006.
• Mills PH, Ahrens ET: Enhanced detection of paramagnetic contrast agents in magnetic resonance images via phase image cross-correlation analysis.  Biomedical Imaging: Macro to Nano, 2006.  3rd IEEE International Symposium: 21-24, 2006.
• Ahrens ET, Goins WF, Robison CS:  Genetic approaches for modulating MRI contrast.  In Molecular and Cellular MRI, eds JWM Bulte and M Modo, CRC Press, San Diego: 123-140, 2007.
• Eagleson KL, Schlueter McFadyen-Ketchum LJ, Ahrens ET, Mills PH, Does M, Nickols J, Levitt P:  Disruption of Foxg1 expression by knock-in of CreRecombinase effects on the development of the mouse telencephalon.  J Neurosci 148: 385-399, 2007.

• Mills PH, Ahrens ET: Theoretical MRI contrast model for exogenous T2 agents.  Magn Reson Med 57: 442-447, 2007

• Srinivas M, Morel PA, Ernst LA, Laidlaw DH, Ahrens ET:  Fluorine-19 MRI for visualization and quantification of cell migration in a diabetes model.  Magn Reson Med 58: 725-734, 2007.