Professional Experience

SEPT. 1990 - PRESENT MEDICAL IMAGING SPECIALIST

MCCONNELL BRAIN IMAGING CENTER, MONTREAL NEUROLOGICAL INSTITUTE & HOSPITAL

• Developed and implemented a 3-D computer simulation system to model data acquisition and image reconstruction of a positron emission tomography.

• Conducted PET phantom experiments to calibrate/validate simulation algorithms that include 3-D sampling geometry and detector response, detection efficiency and deadtime, photon attenuation, scatter, randoms, and counting statistics.

• Modified and installed reconstruction programs on GE's brain (PC2048-15B) and body (PC4096-15WB) PET scanners to analyze/reconstruct real and simulated projection data. Improved scatter and attenuation correction algorithms.

• Performed simulation studies to evaluate image distortions in PET emission and transmission scans using anatomy-based brain models from MR/CT images. Compared different scatter and attenuation correction methods.

• Conducted MR/PET phantom scans to characterize the spatial variability of regional bias and variance in CBF and FDG images. Developed methods to optimize image reconstruction parameters and region of interest analysis.

• Wrote 3-D image processing and modeling programs in network-based computing environment. Developed X window graphics tools to analyze and visualize 4-D medical data. Performed numerical computations in both time and frequency domains.

• Translated the PET scanner's image reconstruction program (Vms Fortran) to C and implemented the code on Unix computers. Ported a CT simulation and reconstruction system (SNARK89) from SUN to SGI. Performed C-Fortran-Matlab interface programming on SUN/SGI platforms.

• Collaborated in the following application projects using the PET simulation system:
  • evaluation and in vivo correction of 3-D partial volume effects in regional time activity curves from dynamic PET images, using co-registered MR scans of the same brain;

  • development of statistical iterative PET image reconstruction algorithms incorporating correlated structural information from MRI data;

  • study of the signal-to-noise issues in PET activation scans and design of optimal imaging protocols;

  • evaluation and optimization of data collection strategy and kinetic parameter estimation algorithms;

  • validation of the accuracy of multi-modality registration algorithms between PET, SPECT, MR and CT images.

• Assisted in performing PET, SPECT and MR scans of physical brain phantoms to validate these projects. Acquired training and practice in quality assurance of medical imaging systems, preparation and safe handling of radioactive substance and contrast agent.

• Installed and verified the PET simulation programs at the Johns Hopkins University Hospital to correct partial volume distortions in radioligand neuroreceptor imaging of patients and controls.

• Improved 3-D medical imaging tools for tissue classification, structure segmentation, image registration/integration, and correlation analysis of dynamic PET images with anatomical regions of interest from MRI data.

JAN. 1988 - AUG. 1990 RESEARCH AND TEACHING ASSISTANTS

DEPARTMENT OF PHYSICS & SOLID STATE PHYSICS LAB, QUEEN'S UNIVERSITY

• Assisted in expanding a research facility to study electron transport and photo-excitation processes in semiconductor micro-structures. Performed dedicate experiments to measure electron mobility, temperatures, energy-loss rates and thermoelectric power in GaAs-based heterostructures, under light illumination and low frequency electromagnetic fields.

• Worked on electronic instrumentation, computer-aided data acquisition, digital signal processing and numerical analyses. Operated and maintained low temperature (1 K), strong magnetic field (8 T) and high vacuum systems.

• Supervised undergraduate students in the first and second year experimental physics courses. Taught tutorial sessions, marked lab reports and assignments. Assisted two MSc candidates to complete their experiments.

SEPT. 1985 - DEC. 1987 RESEARCH AND TEACHING ASSISTANTS

PHYSICS DEPARTMENT & MAGNETIC MATERIALS INSTITUTE, LANZHOU UNIVERSITY

• Set up and improved electromagnetic measurement apparatus to characterize and calibrate newly fabricated magnetic recording medium. Taught the fourth year physics majors class to conduct the experiments and graded lab reports. Supervised two BSc students to finish their graduation projects and theses.