PRINCIPAL INVESTIGATORS

Yihong Yang, Ph.D., Senior Investigator

Chief, FMRI Section

Post-doctoral Training - Functional MRI, Laboratory of Diagnostic Radiology Research, Clinical Center, National Institutes of Health

Ph.D. - Biophysics, University of Illinois at Urbana-Champaign, Urbana; Advisor: Dr. Paul C. Lauterbur

RESEARCH INTERESTS

Our research goal is to develop advanced functional and structural magnetic resonance imaging/spectroscopy techniques and to evaluate their potentials in neuropharmacological applications.

We have been working on the development of functional magnetic resonance imaging (fMRI) techniques to measure evoked and resting activity of the brain. In evoked-fMRI, brain activation is detected using multiple parameters that provide complementary and quantitative measurements. In resting state fMRI, new acquisition and analysis strategies are developed to assess alterations of brain circuitries in patients. In particular, we are evaluating these fMRI techniques in drug addiction applications.

We are investigating structural MRI techniques to assess tissue integrity related to brain dysfunctions. Diffusion tensor imaging (DTI) and beyond DTI techniques are developed to examine microstructural changes in white and gray matter and fiber bundles are delineated by tractography techniques. Novel image registration methods based on implicit reference are developed for more accurate group analysis. We are also developing voxel-wise methods to evaluate structural changes in the brain and evaluating these methods in substance abuse populations.

We have been developing magnetic resonance spectroscopy (MRS) techniques to measure metabolite and neurotransmitter concentrations in the brain. Specifically, we are focusing on the detection and quantification of glutamate, glutamine, and GABA levels. New methods are developed to measure these compounds reliably and evaluate their applications in neuropharmacological studies.

We are also investigating underlying neuronal mechanisms of resting-state fMRI signals using animal models. Electrophysiological and fMRI signals from the rat brain are integrated to reveal the neuronal origins of the resting fMRI signal.

Selected Publications:

1. Geng, X., Christensen, G., Gu, H., Ross, T. J., & Yang Y. (in press). Implicit reference-based group-wise image registration and its application to structural and functional MRI. NeuroImage.

2. Shin, W. Y., Gu, H., & Yang, Y. (2009). Fast high-resolution T1 mapping using inversion-recovery look-locker echo-planar imaging at steady state: Optimization for accuracy and reliability. Magnetic Resonance in Medicine, 61, 694-701.

3. Wu, C. W., Gu, H., Lu, H., Stein, E. A., Chen, J. H., & Yang, Y. (2009). Mapping functional connectivity based on synchronized CMRO₂ ; fluctuations during the resting state. NeuroImage, 45, 694-671.

4. Hong, L. E., Gu, H., Yang, Y., Ross, T. J., Salmeron, B. J., Buchholz, B. et al. (2009). Nicotine addiction and nicotine's actions are associated with separate cingulate cortex functional circuits. Archives of General Psychiatry, 66, 431-441.

5. Yang, S., Hu, J., Kou, Z., & Yang, Y. (2008). Simultaneous detection of unobstructed glutamate and glutamine using standard STEAM with optimized sequence parameters at 3, 4, 4.7, 7, and 9.4 teslas. Magnetic Resonance in Medicine, 59, 236-244.

6. Lu, H., Zuo, Y., Gu, H., Waltz, J. A., Zhan, W, Scholl, C. A., et al. (2007). Synchronized delta oscillations correlate with the resting-state fMRI signal. Proceedings of the National Academy of Sciences, 104, 18265–18269.

7. . Lu, H., Xi, Z. X., Gitajn, L., Rea, W., Yang, Y., & Stein, E. A. (2007). Cocaine-induced brain activation detected by dynamic manganese-enhanced magnetic resonance image (MEMRI). Proceedings of the National Academy of Sciences, 104, 2489–2494.

8. Yang, S., Ross, T. J., Zhang, Y., Stein, E. A., & Yang, Y. (2005). Head-motion suppression using real-time feedback of motion information and its effects on task performance in fMRI. NeuroImage, 27, 153–162.

9. Yang, Y., Gu, H., & Stein, E. A. (2004). Simultaneous MRI acquisition of blood volume, blood flow and blood oxygenation information during brain activation. Magnetic Resonance in Medicine, 52, 1407–1417.

10. Zhan, W., Stein, E. A., & Yang Y. (2004) Mapping the orientation of intravoxel crossing fibers based on the phase information of diffusion circular spectrum. NeuroImage, 23, 1358–1369.