1. Topics in Medical Physics Xiaoming Zheng, PhD. School of Dentistry and Health Sciences December 2009, Chengdu.

2. Medical Physics at CSU Major medical imaging modalities Physics in nuclear medicine Magnetic resonance imaging Physics in computed tomography Ultrasound physics Health physics.

3. Major Imaging Modalities

7. Typical CT Images

8. Positron Emission Tomography

9. On Site Cyclotron

10. Whole Body PET Images

11. Magnetic Resonance Imaging

12. MRI Radio Frequency Coils

13. MRI Pulse Sequence

14. MRI Tissue Contrast Images

15. Ultrasound Imaging

16. Ultrasound Image

17. Medical Physics Research Topics Image reconstruction algorithms Scatter and resolution corrections Image quality assessment Clinical image analysis Computer aided diagnosis Radiation Detectors

18. Filtered Back-Projection

19. Butterworth Filter and Cutoff Frequency

20. Iterative Reconstruction

21. Rescaled Block Iterative Reconstruction Algorithm

22. Attenuation Compensation

23. Scatter Compensation

24. Resolution Compensation

25. PET simulation using GEANT

26. Problems in Dual Radionuclide Imaging: Scatter and Cross-talk

27. The Neural Network

28. Receiver Operating Characteristics

29. Numerical Observers

30. Image Registration Composite using intensity- based registration Composite using point- based registration

31. Brain Activation Mapping

32. 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,

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

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

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

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

37. 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

38. The GaAs detectors

40. Hybrid Modalities – PET/CT

41. Hybrid Imaging Systems

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

43. Optical Imaging

44. Teraherts Imaging

45. 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

46. Magnetoencephalography

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