1. First Pass in Nuclear Cardiology
Presented by Jennifer S. Love, CNMT, NCT, PET

2. Objectives
Examine the concept of First Pass and its role in Nuclear Cardiology imaging.
Define and describe the necessary technical aspects of First Pass in order to obtain quality information.
Evaluate radiopharmaceuticals that can be used to perform the procedure.
Compare and contrast various methods of obtaining an ejection fraction and the advantages and disadvantages of each.

3. What is First Pass?
“A dynamic series of images of a radiopharmaceutical bolus as it flows sequentially from the vena cava into the right atrium, right ventricle, pulmonary arteries and lungs, left atrium, left ventricle, and aorta.”
Nuclear Cardiology Technology Study Guide 2010 SNM, Inc., p.30.

4. Why do a First Pass?
Evaluate for cardiotoxicity in patients undergoing chemotherapy treatment
Reproducible RVEF and LVEF
Evaluation of Left-to-Right Shunt (bump on pulmonary TAC)
True STRESS EF (acquired during actual exercise)
Comparison of Rest and Stress EF can help evaluate for Triple Vessel Disease

5. This is what we are after!
Stress FP
Rest FP

6. How does it work?

7. Crystal technology Single crystal = gamma camera
Multi-crystal = First Pass
Solid state detector = (CZT) the future of imaging technology?!

8. Single crystal NaI (Tl)
Emit a flash of light proportional to the energy of the photon that is stopped by the crystal. PMT’s then convert the light into electrical pulses.

9. Multi-crystal
Multiple crystals associated with an individual PMT on the detector assembly
Principles and Practice of Nuclear Medicine, Paul J. Early and D. Bruce Sodee, 2nd edition, p.253.

10. Solid State Detector CZT = Cadmium Zinc Telluride
Converts the incident photon directly into electrical pulses
High sensitivity
High resolution

11. PROCEDURE

12. How does it all happen?
Verify patient identification using two identifiers (National Patient Safety Goal)
Start an IV
Position the patient
Connect the dose
“load the line”
Start the acquisition
Push, push, push!! (2-3 sec for good quality bolus)

13. IV Access
Antecubital or external jugular preferred (according to ASNC guidelines)
Right arm > left arm
18 to 22 gauge catheter
Portacath, Hickman, PICC line (central lines)

14. Set-up Extension tubing Three-way stopcock 10 – 20ml saline flush
Dose (10 – 30 mCi in ml)

15. Patient Positioning Anterior or slightly RAO Upright or supine
Shallow RAO helps eliminate anatomic overlap
May want to use transmission source
Upright or supine
Pulmonary background is reduced in the upright orientation

16. Connect the dose Needs to be luer lock not a slip lock!
Extension tubing
3-way stopcock
10-20ml saline flush
Needs to be luer lock not a slip lock!

17. GO TIME!! “load the line” Press START Push, push, push!!!
2 – 3 sec for a good bolus

18. TRIVIA QUESTION!!!

19. What is the only Tc radiopharmaceutical that may NOT be used to perform a FIRST PASS?

20. Tc Radiopharmaceuticals
99mTc-DTPA
99mTc-Tetrofosmin
99mTc-Sestamibi
99mTc-MDP
99mTc-MAA
99mTc-MAG3
99mTc-Tagged RBC’s
99mTc-Pertechnetate

21. 99mTc MAA (because it gets trapped in the lungs)!
RV – LUNGS - LV
All the other RP’s circulate all the way through the heart – MAA stops in the lungs!

22. 99mTc-DTPA RP of choice is…
because of its renal excretion, minimizing radiation exposure to the patient

23. Watch this!!!

24. Acquire the raw data
Evaluate the bolus
Evaluate the beat histogram
Pulmonary Transit Time
Right Ventricle Ejection Fraction
Left Ventricle Ejection Fraction

25. Evaluating the Bolus

26. Beat Histogram
ED = End Diastole
ES = End Systole

27. Pulmonary Transit Time

28. Right Ventricle

29. Right Ventricle
ED = End Diastole
ES = End Systole

30. Left Ventricle

31. Left Ventricle
ED = End Diastole
ES = End Systole

32. First Pass at Stress

33. Comparison of Rest vs. Stress

34. Comparison of Rest vs. Stress

35. First Pass vs. MUGA First Pass MUGA Advantages Advantages
Reproducibility
Lower radiation exposure when compared to tagged RBC’s
30 sec acquisition
Measurement of RVEF
True stress EF
Disadvantages
Technical pitfalls
Camera/computer need to be able to accept lots of counts in short time frame
Advantages
No specialty camera needed
IV placement is not an issue
Disadvantages
Need to tag red blood cells
Longer acquisition time
Higher radiation exposure

36. Questions?