bioimaging sciences | faculty | Zubal I. George Zubal, Ph.D. Associate Professor of Diagnostic Radiology Ph.D. Biophysics, University of Saarland, 1981. Yale University, School of Medicine Department of Diagnostic Radiology zubal-george@yale.edu

Nuclear Medicine provides a noninvasive method to image human organ functions (e.g. ventilation, blood flow, brain activity, etc.) by detecting very low levels of radio- pharmaceuticals injected into the body. These radio-pharmaceuticals are radioactive analogues of naturally occurring bio-molecules. By studying their transport through the body, we directly measure the functions of human organs.

One area of research in Nuclear Medicine applies mathematical models to simulate the anatomy of the human and implements Monte Carlo algorithms to calculate the interactions of radiation as it passes through human tissue. These simulations model the important physics of the imaging instrumentation. With such a complete mathematical representation of the radio-pharmaceutical, patient, and camera, we study the image formation process in detail. Projects within Nuclear Medicine mathematically model organs as compartments to more accurately determine organ function from external camera measurements. Also, new camera designs can be invented and tested in these software simulations.

A diagnostic technique has recently emerged which uses two independent imaging modalities fused into a single representation. Processing techniques are applied to PET (Positron Emission Tomography) and SPECT (Single Photon Emission Tomography) 3- dimensional patient images to spatially register them with other modalities which show better detail of the anatomical structures (MRI or CT). The combined information of anatomy registered to SPECT and PET images leads to new methods of analyzing the functional data and presenting important clinical results. Such methods are being applied to whole brain images of epilepsy patients and help to locate areas of the brain which initiate seizures.

Representative Publications:

Zubal IG, Harrell CR, Smith EO, Rattner Z, Gindi G, Hoffer PB., " Computerized three- dimensional segmented human anatomy.", Med Phys 1994 Feb;21(2):299-302.

Zubal IG, Harrell CH. “Voxel based Monte Carlo Calculations of Nuclear Medicine Images and Applied Variance Reduction Techniques.” Image acd nd Vision Computing, 1992 July/Aug; 10(6):342-348.

Dagli M, Caride V, Carpenter S, Zubal IG “Compartmental Analysis of the Complete Dynamic Scan Data for Camera-Based Determination of Effective Renal Plasma Flow”, J Nucl Med, 1997 Aug;38(8):1285-90.

Spanaki MV, Spencer SS, Corsi M, MacMullan J, Seibyl J, Zubal IG, “Sensitivity and specificity of quantitative difference SPECT analysis in seizure localization.”, J Nucl Med, 1999 May; 40(5):730-6.

Zubal IG, Avery RA, Stokking R, Studholme C, Corsi M, Dey H, Seibyl JP, Spencer SS. " Ratio-images calculated from interictal positron emission tomography (PET) and single-photon emission computed tomography (SPECT) for quantification of the uncoupling of brain metabolism and perfusion in epilepsy.", Epilepsia 2000 Dec;41(12):1560-6.