Comparison of Clinical Tools for Measurements of Regional Stress and Rest Myocardial Blood Flow Assessed with ¹³N-Ammonia PET/CT

Abstract

Several models for the quantitative analysis of myocardial blood flow (MBF) at stress and rest and myocardial flow reserve (MFR) with 13 N-ammonia myocardial perfusion PET have been implemented for clinical use. We aimed to compare quantitative results obtained from 3 software tools (QPET, syngo MBF, and PMOD), which perform PET MBF quantification with either a 2-compartment model (QPET and syngo MBF) or a 1-compartment model (PMOD). Methods: We considered 33 adenosine stress and rest 13 N-ammonia studies (22 men and 11 women). Average age was 54.5 6 15 y, and average body mass index was 26 6 4.2. Eighteen patients had a very low likelihood of disease, with no chest pain, normal relative perfusion results, and normal function. All data were obtained on a PET/CT scanner in list mode with CT attenuation maps. Sixteen dynamic frames were reconstructed (twelve 10-s, two 30-s, one 1-min, and one 6-min frames). Global and regional stress and rest MBF and MFR values were obtained with each tool. Left ventricular contours and input function region were obtained automatically in system QPET and syngo MBF and manually in PMOD. Results:The flow values and MFR values were highly correlated among the 3 packages (R 2 ranging from 0.88 to 0.92 for global values and from 0.78 to 0.94 for regional values. Mean reference MFR values were similar for QPET, syngo MBF, and PMOD (3.39 6 1.22, 3.41 6 0.76, and 3.66 6 1.19, respectively) by 1-way ANOVA (P 5 0.74). The lowest MFR in very low likelihood patients in any given vascular territory was 2.25 for QPET, 2.13 for syngo MBF, and 2.23 for PMOD. Conclusion: Different implementations of 1-and 2-compartment models demonstrate an excellent correlation in MFR for each vascular territory, with similar mean MFR values.

Clinical Quantification of Myocardial Blood Flow Using PET: Joint Position Paper of the SNMMI Cardiovascular Council and the ASNC

“…for 13 N-ammonia 27 and 82 Rb, 28-30 but significant variation remains among some vendor programs. Further standardization of image acquisition and analysis methods will have the benefit of allowing reliable pooling of MBF data as part of large, multicenter clinical trials.…”

PET myocardial perfusion quantification: anatomy of a spreading functional technique

“…Clinical protocols have been suggested for new promising compounds such as 18 F-flurpiridaz [7]. This fluorine-18-based tracer extends the possibilities of perfusion imaging implementation through a regional rather than on-site cyclotron due to its longer half-life (110 min).…”

Flow-Based Functional Assessment of Coronary Artery Disease by Myocardial Perfusion Positron Emission Tomography in the Era of Fractional Flow Reserve

“…Recently it was reported that even shorter acquisition time did not hamper the reproducibility of MBF measurement using 15 O water PET (28). However, MBF values can vary according to which tracers or methods are used (29,30). So, it is recommended that the same tracer, analytical method and software be used Cp (t), arterial input function; C1 (t), 13 N ammonia activity in the freely diffusible compartment; C2 (t), metabolically trapped 13 On the other hand, MBF is affected by many extrinsic factors including age, sex, heart rate, blood pressure and myocardial oxygen consumption (40).…”