# Gullberg Lab

## Research Interest

Our research applies mathematical physics to solve inverse problems in medical imaging. Computer simulated data and data acquired with SPECT/CT and SPECT/MRI hybrid systems from phantom, animal, and human studies are used to develop compartment models for the study of in vivo dynamic physiological processes, the study of the physics of hemodynamic flow in vessels, the measurement of in vivo perfusion and diffusion processes, the study of the relationship between cardiac function and cardiac deformation, and the study of mechanical and electromagnetic inverse problems associated with cardiac function. Our goal is to develop technologies to improve diagnosis and evaluation of therapy for patients with heart failure.

## Projects

- Dynamic cardiac SPECT imaging
- Molecular imaging of cardiac hypertrophy using microPET and pinhole SPECT
- Advanced concepts of gamma-ray imaging using Compton camera technology
- Mechanical modeling of the heart for improved cardiac diagnosis
- Improved cardiac imaging using SPEC/CT with converging collimators
- Improve cardiac resolution in motion-compensated PET
- Tensor tomography applications in MRI and acoustic imaging

## Selected Publications

G. T. Gullberg, F. W. Wehrli, A. Shimakawa, M. A. Simons, “MR vascular imaging with a fast gradient refocusing pulse sequence and reformatted images from transaxial sections,” Radiology, vol. 165, pp. 241-246, 1987.

B. W. Reutter, G. T. Gullberg, R. H. Huesman, “Direct least squares estimation of spatiotemporal distributions from dynamic SPECT projections using a spatial segmentation and temporal B-splines,” IEEE Trans. on Med. Imag., vol. 19, pp. 434-450, 2000.

D. J. Kadrmas, G. T. Gullberg, “4D maximum *a posteriori* reconstruction in dynamic SPECT using a compartmental model-based prior,” Phys. Med. Biol., vol. 46, pp.1553-1574, 2001.

G. T. Gullberg, M. Defrise, V. Y. Panin, G. L. Zeng, “Efficient cardiac diffusion tensor MRI by three-dimensional reconstruction of solenoidal tensor fields,” Magnetic Resonance Imaging, vol. 19, pp. 233-256, 2001.

A. Sitek, G. T. Gullberg, R. H. Huesman, “Correction for ambiguous solutions in factor analysis using a penalized least squares objective,” IEEE Trans. on Med. Imag., vol. 21, pp. 216-225, 2002.

A. B. Cheryauka, J. N. Lee, A. A. Samsonov, M. Defrise, G. T. Gullberg, “MRI diffusion tensor reconstruction with PROPELLER data acquisition,” Magnetic Resonance Imaging, vol. 22, pp.139-148, 2004.

Q. Tang, G. L. Zeng, G. T. Gullberg, “Analytical fan-beam and cone-beam reconstruction algorithms with uniform attenuation correction for SPECT, “Phys. Med. Biol., vol. 50, pp. 3153-3170, 2005.

A. Sitek, R. H. Huesman, G. T. Gullberg, “Tomographic reconstruction using an adaptive tetrahedral mesh defined by a point cloud,” IEEE Trans. on Med. Imag., vol. 25, pp.1172-1179, 2006.

J. Qi, R. H. Huesman, “Penalized maximum-likelihood image reconstruction for lesion detection,” *Phys. Med. Biol.*, vol. 51, pp. 4017-4029, 2006.

A. I. Veress, W. P. Segars, J. A.Weiss, B. M. W. Tsui, G. T.Gullberg, “Normal and pathological NCAT image and phantom data based on physiologically realistic left ventricle finite-element models,” IEEE Trans. on Med. Imag__.__, vol. 25, pp.1604-1616, 2006.

D. Rohmer, A. Sitek, G. T. Gullberg, “Reconstruction and visualization of fiber and laminar structure in the normal human heart from ex vivo DTMRI data,” Investigative Radiology, vol. 42, pp.777-789, 2007.

A. I. Veress, J. A.Weiss, R. H. Huesman, B. W. Reutter, A. Sitek, S. Taylor, Y. Yang, G. T. Gullberg, “Regional changes in the diastolic deformation of the left ventricle for SHR and WKY rats using 18FDG based microPET technology and hypereleastic warping,” Annals of Biomedical Engineering, vol. 36, pp.1104–1117, 2008.

Q. Huang, J. You, G.L. Zeng, G. T. Gullberg, “Exact reconstruction from uniformly attenuated SPECT partial scan projection data using DBH method,” IEEE Trans. on Med. Imag., vol. 28, pp.17-29, 2009.