RESUMO
PURPOSE: We intended to evaluate myocardial oxygen consumption (MVO2) by applying recirculation correction and modified one-compartment model to have a reference range of MVO2 in normal young population and to reveal the effect of recirculation on time-activity curve (TAC). Materials and METHODS: In nine normal male volunteers with mean age of 26.3+/-4.0, MVO2 was estimated with 925 MBq (25mCi) of 11C-Acetate (Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea) and PET/CT (Biograph 6, Siemens Medical Solution, Germany). Analysis software such as MATLAB(R) v7.1 (Mathworks, Inc., United States), Excel(R) 2007 (Microsoft, United States), and SPSS(R) v12.0 (Apache Software Foundation, United States) were used. Twenty three frames were of 12 x 10, 5 x 60, 3 x 120, 2 x 300's duration, respectively. The modified one-compartmental model and the recirculation correction method were applied. Statistical analysis was performed by using Test of Normality, ANOVA and Post-Hoc (Scheffe's) analysis, and p-value less than 0.05 was considered as significant. RESULTS: The normal reference ranges of MVO2 were presented as 3.18-4.64 x 10(-4) ml/g/sec, 1.91-3.94 x 10(-4) ml/g/sec, 4.31-6.40 x 10(-4) ml/g/sec, 2.84-4.53 x 10(-4) ml/g/sec and 3.42-5.00 x 10(-4) ml/g/sec in the septum, the inferior wall, the lateral wall, the anterior wall and the entire wall, respectively. In addition, it was noted that the dual exponentiality of the clearance curve is due to the recirculation effect and that the characteristic of the curve is essentially mono-exponential. CONCLUSION: 11C-Acetate is a radiotracer worthwhile to assess MVO2. Re-circulated 11C can influence TAC of 11C in myocadia and so the recirculation correction must be considered when measuring MVO2.