Normal Values of Myocardial Blood Flow and Myocardial Flow Reserve Evaluated by 3-Dimensional Dynamic PET or CT System with 13N-Ammonia - Abstract
Purpose: For quantitation of myocardial blood flow (MBF), 2-dimensional (2D) 13N-ammonia PET has been utilized. However, most of recent PET systems operate only 3-dimensional (3D) mode, and there are no reports about normal value of MBF measured by 3D PET/CT system. In this study, we evaluated normal values of MBF and myocardial flow reserve (MFR) with 13N-ammonia by using 3D PET/CT system. Comparisons of values between the present study and previously reports with 2D PET systems were carried out.
Materials and methods: Nine normal volunteers were enrolled. MBF of dipyridamole stress and rest were measured by 3D PET/CT with 13N-ammonia. MBF was measured by 2-compartmet model analysis, and MFR was determined as the ratio of dipyridamole/rest MBF. Finally, we assessed regional (three coronary territories) and global MBF and MFR.
Results: Average MBF at dipyridamole/rest were LAD:3.42 ± 0.73/1.26 ± 0.22, LCX:4.23 ± 1.17/1.20 ± 0.22, RCA:3.68 ± 0.89/1.35 ± 0.82, global:3.69 ± 0.83/1.26 ± 0.31 (mL/min/g), respectively. Average MFR was LAD: 2.74 ± 0.43, LCX:3.54 ± 0.72, RCA:3.20 ± 1.22, global:2.98 ± 0.59, respectively. Those results were almost similar with previous reports with 2D 13N-ammonia PET. However, higher rest MBF and heterogeneity of hyperemic MBF were observed.
Conclusions: Normal values of MBF and MFR with 3D 13N-ammonia PET were almost comparable with the values evaluated by conventional 2D PET. However, it needs further considerations to improve heterogeneity of hyperemic MBF and higher rest MBF.