1. Current Topics in Medical Physics Research Xiaoming Zheng, PhD. School of Dentistry and Health Science Chengdu, China, 2009

2. Current Research Interests Image reconstruction algorithms Scatter and resolution corrections Image quality assessment Clinical image analysis Computer aided diagnosis Radiation detectors

3. Filtered Back-Projection

4. Butterworth Filter and Cutoff Frequency

5. Iterative Reconstruction

6. Rescaled Block Iterative Reconstruction Algorithm

7. Attenuation Compensation

8. Scatter Compensation

9. Resolution Compensation

10. Images Reconstructions Iterative Reconstruction: Rescaled Block Iterative Algorithm including attenuation, scatter, and distance resolution compensation. Parameters tested: iteration 1,3,5,7,10 and post Gaussian filter FWHM 0,1,2,3,4 pixels Filtered Back-Projection: Parameters tested: Butterworth filter cut-off frequencies: 0.10, 0.15, 0.20, 0.25 and 0.30 pixel -1

11. Reconstructed images FBPIterative

12. Human and Numerical Observer Image Quality Studies Human observer study using receiver operating characteristics Numerical observer employing an ideal observer model.

13. Receiver Operating Characteristics

14. Numerical Observers

15. Types of Channels

16. Numerical Observer Results: RBI

17. Human Observer Results

18. Scatter and Cross-talk Correction in Dual Radionuclide Imaging

19. The Neural Network

20. Before Correction After Correction

21. Image Registration

22. Statistical Parametric Mapping

23. Radiation Dose Optimization in CT Biological effect of ionizing radiation Cancer rate vs radiation dose Radiation dose reduction: image quality vs radiation dose Technical parameters: kVp, mAs, etc.

24. CT Scan Parameters and Dose Index ScannerkVpmAsCTDIv (mGy) Brain Toshiba 13019532.2 GE12022046.0 Siemens12048569.8 Abdomen Toshiba 1201509.60 GE12018014.5 Siemens12022016.9

25. CT machine Brain CTDI V (mGy) Image quality rank score Abdomen CTDI V (mGy) Image quality rank score Machine Image quality score average Single slice32.22.859.602.562.71 16 slice46.03.3614.53.283.32 64 slice69.84.4316.94.264.35 CT Dose Index and image quality scores summary

26. Single Slice CT Images

27. 16 Slice CT Images

28. 64 Slice CT Images

29. Computer Assisted Diagnosis Provide second opinion to radiologists. FDA approved systems include breast and lung cancer detections. Image processing Image data base Artificial intelligence.

30. PET/SPECT Simulation Using GEANT

31. Radiation Detectors Room temperature Semiconductor Detectors: Materials and mechanisms Magnetic resonance coils designs.

32. (GE Medical Systems) Detector head Scintillator-based gamma camera

33. CZT / NaI comparison ELGEMS CZT pixilated small field imager Anger camera (NaI) Test image Thyroid phantom

34. CdZnTe (CZT) E h e + - X  CdZnTe: Gamma rays create electron/hole pairs. The gamma energy level is proportional to the electrical current. Semiconductor - CZT

35. The GaAs detectors

37. Hybrid Modalities – PET/CT

38. Hybrid Imaging Systems

39. New Imaging Systems New detector technology. Optical imaging: visible, ultraviolet, inferred. Molecular imaging: PET, fMRI, Optical Hybrid imaging systems. T Herts imaging.

40. Optical Imaging

41. Teraherts Imaging

42. Thickness of tissue probed 30  m 100  m 1mm 1cm 10cm  400 nm 800 nm 1600 nm 10  m 100  m Thermography THz imaging Confocal/ multi-photon microscopy Diffuse optical tomography Optical coherence tomography

43. Magnetoencephalography

44. Medical Physics Topics? Treatment of depression: Transcranial magnetic stimulation. Killing of cancer cells: Electric field on biological molecules.