1. Simulation System for Emission Tomography (SimSET): using simulation to research ideas in emission tomography. Robert L. Harrison, Steven B. Gillispie, Thomas K. Lewellen University of Washington Supported in part by PHS grant CA42593

2. SimSET Freely available. Photon-tracking simulation. PET and SPECT. Well engineered. Command-line driven.

3. Using simulation as a research tool Problem definition. Choosing and installing a simulation. Setting up and running a simulation. Analyzing the data.

4. Problem definition

5. Possible areas of research Optimizing patient studies. Assessing/improving quantitation. Designing tomographs.

6. Diffuse lung disease Reproducing work by Chicco et al. * Can disease be detected in SPECT scans of the lungs? Cold lesions in hot lung. Vary size of lesions. 30% of lung volume affected. * Chicco, Eur J Nucl Med, 28:150-154.

7. Choosing and installing a simulation

8. Choosing SimSET

9. Installing SimSET Download from website. Unpack (e.g., gunzip). Customize links to your system. Make run file.

10. Setting up and running a simulation

11. General setup Scan time, number of decays, … Location of parameter files, data tables, etc. Object (phantom/patient) geometry. Tomograph geometry. Output specification.

12. Defining the object Define the activity and attenuation objects. We are using the NCAT phantom. * * Segars and Tsui, IEEE Trans Nucl Sci, 49:3:675-679, 2002.

13. Defining the tomograph Collimator parameter file. –LEGP. Detector parameter file. –Planar detector.

14. Defining the output 62 slices. Distance-angle sinograms (128 angles over 360°, 128 3mm distance bins). 10% energy window.

15. Analyzing the data

16. Filtered backprojection reconstruction. Observer study.

17. No lesions 8mm 3 lesions16mm 3 lesions

18. SimSET Summary Freely available emission tomography simulation. Efficient, easy-to-use. Useful for a broad range of research.

19. For further information Website: –http://depts.washington.edu/simset/html/simset_main.html Contact: –simset@u.washington.edu