Cardiac PET vs SPECT

1. When is PET
better choice
than SPECT
7/3/2019
Ihab suliman
Consultant Cardiologist NGHA Riyadh KSA
MBBS ECFMG MRCP(UK) MRCP Specialty(Endocrinology &DM) ABcv FESC CBNC
0505244473
Ihab.suliman@gmail.com

2. The cardiac imaging market is
transitioning
SPECT PET
Cardiac catheterization CT angiography

3. PET advantages
Variable SPECT PET
Spatial Resolution X 3 times better
Contrast resolution X 2 times better
Count density/unit time X 4 times better
Attenuation Correction Optional Routine
Scatter Correction Optional 5 times better
Resolution Recovery Optional Routine

4. SPECT perfusion imaging
 Low energy photons
 Thallium or Tc based
 Usually two imaging sequences (20-30 minutes
each)
 Total exam time 3-4 hours, Less time with CZT
camera.
 Study of over 3000 patient with Thallium
 Sensitivity 84% and Specificity 53%
 Attenuation/motion all impact relative accuracy
 Equivocal studies men 10% woman 30-40%

5. Case study
 50yo female patient OBESE with breast
implants
 MPS ordered for evaluation of chest
pain .
 Patient underwent MPS with Tc-99m Sestamibi
 Patient then underwent Rb-82 PET perfusion

6. SPECT 4- 6 Hours or 2 day protocol
PET 30 minutes

7. Case Study
 Comparison between SPECT and PET
 Normal scan with Rb-82 PET
 Abnormal with SPECT
 False positive SPECT, patient risk stratified
away from invasive evaluation
 No cardiac events in follow up

8. PET perfusion
2. Nuclear Medicine Self-Study Program III:
Nuclear Medicine Cardiology. Botvinik, EH, Ed.
1998: Society of Nuclear Medicine, Reston, VA.
Author # Patients
Gould 50
Demer 193
Go
Sensitivity Specificity
95% 100%
94% 95%
93% 78% 202
45
49
146
319
Schelbert 97% 100%
Yonekura 93% 100%
Williams 98% 93%
Stewart 84% 88%
Weighted 93% +/- 8 92% +/- 5 766
Avg.

9. Economic impact on society
 Single missed diagnosis of CAD-$90,000
 SPECT imaging $932.07
 PET imaging – Iowa $2,467.77
 300 patients
 SPECT over 32% referred for coronary angiography
 PET only 10% referred for coronary angiography
 Additionally 20% of catheterization were normal in
the face of a abnormal SPECT study (false
positives)
 PET imaging lead to a cost savings of 30-40%

10. 36 inch separation
for patient access
GEMINI Open PET/CT
Advantage
Integrated operation
(CT/PET Imaging)
Separated operation
(Independent CT simulation /
diagnostic CT or PET)
195 cm PET coverage in closed
position
130 cm PET coverage in
open

11. Sample PET/CT Protocol
Protocol courtesy of Marcelo DiCarli, MD
Approximately 30 minutes
scoutCT-trans
Rb-82
50- 60 mCi
70-90 sec
90-120 sec
gated
rest
pt out
Dipy
0.56
mg/kg,Dob,Reg
adenoson
scoutCT-trans
70-90 sec
90-120 sec
Rb-82
50- 60 mCi
gated
stress
Approx 1 min Approx 7 min Approx 6 min Approx 1 min Approx 7 min

12. Why Rb-82 now?
 Improved patient outcomes/lower false positives.
 Appointment times reduced to 30 minutes.
 Improved accuracy irrespective of body mass
index, sex ect.
 Lower radiation exposure.
 Sarcoidosis & Endocarditis .
 Myocardial Viability.

13. Patient Radiation Dosimetry
Isotope Effective
Dose
Equivalent
Per study Total
Rb-82 1.6 mrem/mCi 50 mCi 80 mrem
Tc-99m
mibi
51 mrem/mCi 30 mCi 1500 mrem
Th-201 850
mrem/mCi
4 mCi 3200 mrem
CT mu-
map
440 mR 1 scan 440 mrem
Copyright Dr. Mark Nathan

14. ESCARDIO 2015

16. ACTIVE
SARCOIDOSIS

17. MRI in sarcoidosis

18. 67 years old male with Recent anterior
MI from another hospital. EF 25%.
Diffuse 3VD.
Myocardial
Viability Case
In MCICU he
had Multiple
and Recurrent
VF/VT.
EP labelled
him as
ischemic
VF/VT
Cardiac
surgeon
insisted on
Viability
Before CABG

20. Conclusion
PET vs SPECT
• If Possible, Send all for PET.
• It is definitely better than SPECT/CZT but not
much better.
• Thin Males with Lower Risk for SPECT.
• In Sarcoidosis and endocarditis and when
Myocardial Viability is a big question PET is the
almost the only choice.