SUBJECT: Ph.D. Dissertation Defense
BY: Desiree Jangha
TIME: Wednesday, March 29, 2006, 10:15 a.m.
PLACE: Neely Building, 118
TITLE: Quantitative Conjugate Imaging of Iodine-123 and Technetium-99m Labeled Brain Agents in the Basal Ganglia
COMMITTEE: Dr. Chris C-K Wang, Chair (ME)
Dr. John N. Aarsvold (Emory University)
Dr. Nolan Hertel (ME)
Dr. Farzad Rahnema (ME)
Dr. Paul J. Benkeser (BME)


In this dissertation the concept of classic conjugate imaging, a non-tomographic nuclear medicine technique was applied to estimate the activity of the radio-pharmaceutical distribution in the striata. A mathematical model that extends the application of classic conjugate imaging to include activity estimation of two distinct and aligned activity distributions was developed. Phantom experiments were performed to evaluate the accuracy of the model. Monte Carlo simulations were performed to determine the shielding design and characterize said design for a dedicated conjugate imaging system currently under construction. Monte Carlo simulations were also performed to evaluate the accuracy of the modified conjugate imaging technique used with the dedicated conjugate imaging system. Scatter correction was performed on the simulated data to correct for downscatter from high-energy photon emission and the inclusion of scatter photons in the lower half of the photopeak window. It is shown that the modified conjugate imaging technique developed in this dissertation was able to accurately estimate activity uptake in each of two distinct activity distributions. The accuracy of the technique was comparable to clinical quantitative SPECT studies. The modified conjugate imaging technique in conjunction with the dedicated conjugate imaging system is, therefore, a viable quantitative nuclear medicine technique for activity estimation of the striata of Parkinsonian and schizophrenic patients. Its portability and low cost relative to SPECT systems make the dedicated conjugate imaging system advantageous for clinics with Parkinsonian and schizophrenic patients, who are unable to travel due to physical or mental limitation.