Reproducibility of measurements of regional myocardial blood flow in a model of coronary artery disease: Comparison of H215O and 13NH3 PET techniques.
PET absolute myocardial blood flow (MBF) with H(2)15O and 13NH3 are widely used in clinical and research settings. However, their reproducibility with a 16-myocardial segment model has not been examined in chronic coronary artery disease (CAD). We examined the short-term reproducibility of PET H(2)15O MBF and PET 13NH3 MBF in an animal model of chronic CAD.


METHODS
Twelve swine (mean weight +/- SD, 38 +/- 5 kg) underwent percutaneous placement of a copper stent in the mid circumflex coronary artery, resulting in an intense inflammatory fibrotic reaction with luminal stenosis at 4 wk. Each animal underwent repeated resting MBF measurements by PET H(2)15O and PET 13NH3. Attenuation-corrected images were analyzed using commercial software to yield absolute MBF (mL/min/g) in 16 myocardial segments. MBF was also normalized to the rate.pressure product (RPP).


RESULTS
By Bland-Altman reproducibility plots, the mean difference was 0.01 +/- 0.18 mL/min/g and 0.01 +/- 0.11 mL/min/g, with confidence limits of +/-0.36 and +/-0.22 mL/min/g for uncorrected regional PET H(2)15O MBF and for uncorrected regional PET 13NH3 MBF, respectively. The repeatability coefficient ranged from 0.09 to 0.43 mL/min/g for H(2)15O and from 0.09 to 0.18 mL/min/g for 13NH3 regional MBF. RPP correction did not improve reproducibility for either PET H(2)15O or PET 13NH3 MBF. The mean difference in PET H(2)15O MBF was 0.03 +/- 0.14 mL/min/g and 0.02 +/- 0.19 mL/min/g for infarcted and remote regions, respectively, and in PET 13NH3 MBF was 0.03 +/- 0.11 mL/min/g and 0.00 +/- 0.09 mL/min/g for infarcted and remote regions, respectively.


CONCLUSIONS
PET H(2)15O and PET 13NH3 resting MBF showed excellent reproducibility in a closed-chest animal model of chronic CAD. Resting PET 13NH3 MBF was more reproducible than resting PET H(2)15O MBF. A high level of reproducibility was maintained in areas of lower flow with infarction for both isotopes.
Chareonthaitawee
Panithaya
P
Division of Cardiovascular Diseases, Mayo Clinic and Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA. chareonthaitawee.panithaya@mayo.edu
Christenson
Stuart D
SD
Anderson
Jill L
JL
Kemp
Brad J
BJ
Hodge
David O
DO
Ritman
Erik L
EL
Gibbons
Raymond J
RJ
D000818:Animals; D001783:Blood Flow Velocity; D003324:Coronary Artery Disease / Q000473:pathology*; D003326:Coronary Circulation; D004195:Disease Models, Animal; D006439:Hemodynamics; D007091:Image Processing, Computer-Assisted; D009206:Myocardium / Q000473:pathology; D009590:Nitrogen Radioisotopes; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D013552:Swine
D009590:Nitrogen Radioisotopes; D010104:Oxygen Radioisotopes