Joe O’Brien & Bill Thomson, City Hospital, Birmingham

1. A Survey of Current Acquisition & Analysis Techniques for Myocardial Perfusion Imaging Using Philips Gamma Cameras Joe O’Brien & Bill Thomson, City Hospital, Birmingham & Cariss Bird, Priory Hospital, Birmingham

2. Introduction • Aware of some variation amongst Philips users in acquiring and analysing Myocardial Perfusion Imaging (MPI) studies. • Decided to provide a survey for Philips NMUG Meeting. • The survey would be beneficial: • Forms a basis of discussion at UG Meeting. • Allows users to compare their technique with others.

3. ADAC Systems Marconi & Picker Systems Cariss Bird Joe O’Brien Survey & Presentation Due to work commitments and time constraints, just the Marconi & Picker users have been surveyed.

4. The Survey • 30 customers on Philips NM customer list • Contacted via telephone for anonymous survey • 12 customers do not perform MPIs • 1 customer did not participate • So 17 customers surveyed • Completed surveys available

5. The Survey e.g. how many patients per year? • Basic Questions • Radio-pharmaceutical e.g. type of RP, activity per test, delay time? • Gamma Camera e.g. which camera and collimator do you use? • Acquisition e.g. matrix size & zoom (pixel size), orbit setup, gated or non-gated? • Reconstruction e.g. FBP or iterative reconstruction, Pre-filter or 3D Post filter ?

6. Basic Questions

7. MIBI (5) Tetrofosmin (12) Radiopharmaceutical • Most commonly used:

8. 1 Day 1000MBq (2) 2 Day 400MBq (15) Radiopharmaceutical • Protocol:

9. MIBI Tetro Radiopharmaceutical • Imaging Delay Time:

10. (1) (2) (11) (4) Cameras Included in Survey • Dual headed AXIS most common • Exclude others from presentation

11. Acquisition Settings Used By All AXIS Users • Orbit settings: • Non-Circular • Head Orientation at 102° • 102° of rotation per head • 34 projections per head • Acquisition based on TIME per step • Factory set energy window

12. Variable Acquisition Settings • Orbit setting • Step & Shoot - 3 Continuous - 8 • Gating • Gated - 5 Non-Gated - 6 • BEACON • Used - 3 Not Used - 8

13. Variable Acquisition Settings • Time per step

14. LEHR (5) LEGAP (6) Variable Acquisition Settings • Collimator

15. Variable Acquisition Settings • Matrix & Zoom (i.e Pixel Size)

16. Reconstruction Settings Used By All AXIS Users • Routinely Check for Patient Motion • No Pre-filtering of data • All use 3D Post-filter

17. Don’t Know (1) Iterative (3) FBP (7) Variable Reconstruction Settings • Reconstruction Method

18. Don’t Know (2) Varied between patients (1) Left as Default (8) Variable Reconstruction Settings • Diameter • Effectively zooms data and alters pixel size.

19. Variable Reconstruction Settings • Filter • All used ‘Low Pass’ but with variable settings:

20. Emory (1) QGS (4) Variable Reconstruction Settings • Gated Analysis Programs

21. Conclusions • Survey of Philips NM Users performing MPI. • Majority using AXIS system. • Users have some similar methods of acquisition and analysis. • But overall there are significant differences e.g. 1/2 use LEHR, the other 1/2 use LEGAP • Worthy of discussion at UGM!

22. Effect of Collimator • Local standard protocol for MPI uses LEGAP collimator. • We considered the effect on lesion detectability using a LEHR collimator instead. • Scanned a torso phantom fitted with a cardiac insert • Installed a large 100% and small 50% defect. • Filled with 8MBq Tc-99m

23. Effect of Collimator • Short Axis Images HR GP • Qualitatively, there is no discernable difference in lesion detectability

24. Effect of Collimator • HLA Images HR GP • Qualitatively, no discernable difference in lesion detectability. • But up to 40% more counts.