@article {Rimoldi163, author = {Ornella Rimoldi and Klaus P. Sch{\"a}fers and Ronald Boellaard and Federico Turkheimer and Lars Stegger and Marilyn P. Law and Adriaan A. Lammerstma and Paolo G. Camici}, title = {Quantification of Subendocardial and Subepicardial Blood Flow Using 15O-Labeled Water and PET: Experimental Validation}, volume = {47}, number = {1}, pages = {163--172}, year = {2006}, publisher = {Society of Nuclear Medicine}, abstract = {The purpose of this study was to assess the feasibility and accuracy of quantifying subendocardial and subepicardial myocardial blood flow (MBF) and the relative coronary flow reserves (CFR) using 15O-labeled water (H215O) and 3-dimensional{\textendash}only PET. Methods: Eight pigs were scanned with H215O and 15O-labeled carbon monoxide (C15O) after partially occluding the circumflex (n = 3) or the left anterior descending (n = 5) coronary artery, both at rest and during hyperemia induced by intravenous dipyridamole. Radioactive microspheres were injected during each of the H215O scans. Results: In a total of 256 paired measurements of MBF, ranging from 0.30 to 4.46 mL{\textperiodcentered}g-1{\textperiodcentered}min-1, microsphere and PET MBF were fairly well correlated. The mean difference between the 2 methods was -0.01 {\textpm} 0.52 mL{\textperiodcentered}g-1{\textperiodcentered}min-1 with 95\% of the differences lying between the limits of agreement of -1.02 and 1.01 mL{\textperiodcentered}g-1{\textperiodcentered}min-1. CFR was significantly reduced (P \< 0.05) in the ischemic subendocardium (PET = 1.12 {\textpm} 0.45; microspheres = 1.09 {\textpm} 0.50; P = 0.86) and subepicardium (PET = 1.2 {\textpm} 0.35; microspheres = 1.32 {\textpm} 0.5; P = 0.39) in comparison with remote subendocardium (PET = 1.7 {\textpm} 0.62; microspheres = 1.64 {\textpm} 0.61; P = 0.68) and subepicardium (PET = 1.79 {\textpm} 0.73; microspheres = 2.19 {\textpm} 0.86; P = 0.06). Conclusion: Dynamic measurements using H215O and a 3-dimensional{\textendash}only PET tomograph allow regional estimates of the transmural distribution of MBF over a wide flow range, although transmural flow differences were underestimated because of the partial-volume effect. PET subendocardial and subepicardial CFR were in good agreement with the microsphere values.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/47/1/163}, eprint = {https://jnm.snmjournals.org/content/47/1/163.full.pdf}, journal = {Journal of Nuclear Medicine} }