Impact of time-of-flight PET in a quantitative analysis on myocardial perfusion studies using 13N-ammonia

1742 Objectives Time-of-flight (TOF) PET reconstruction has improved signal-to-noise ratio in whole-body oncologic application. However, few studies have reported the effect of TOF to a quantitative analysis in myocardial perfusion PET studies. The aim of this study was to elucidate the impact of TOF for myocardial blood flow (MBF) and myocardial flow reserve (MFR). Methods Sixteen consecutive subjects carried out rest (lower gamma counts) and adenosine stress (higher gamma counts) 13N-ammonia myocardial perfusion PET. All data were obtained on GEMINI TF-16 (Philips), a TOF-PET/CT scanner, in list mode. The same twenty seven dynamic frames data were reconstructed (twenty four 5-s, two 30-s, and one 1-min frames) using TOF and 3D row-action maximum likelihood algorithm (RAMLA). The rest and stress MBF as well as MFR values by segment based on 17-segment model (AHA) were determined using a DeGrado 1-compartment system (PMOD software). The quantitative MBF and MFR values with TOF and 3D RAMLA reconstructions were compared in a total of 272 (16*17) segments. Results Both of rest and stress MBF values with TOF were higher than those of 3D RAMLA, respectively (rest: 0.951 ± 0.195 vs. 0.806 ± 0.141, p Conclusions TOF reconstruction increased MBF, especially under relative low perfusion conditions. TOF and non-TOF PET/CT system might need each abnormal threshold of MBF and MFR, respectively.