Use of gated N-13-NH3 micro-PET to examine left ventricular function in rats

Introduction: Myocardial perfusion gating techniques offer the possibility of measurement of left ventricular end-systolic (ESV) and end-diastolic volume (EDV) and left ventricular ejection fraction (LVEF) in clinical and preclinical trials. The aim of this study was to evaluate left ventricular volumes (LVV) and LVEF with N-13-NH3 in comparison with the reference F-18-FDG in different rat models. Methods: In this study, 18 male Wistar rats, 12 control rats and 6 rats with myocardial infarction (MI) were imaged with micro-PET. The rats were scanned with gated N-13-NH3 and F-18-FDG sequentially for the assessment of LVV and LVEF. A validated three-dimensional segmentation algorithm was used to calculate LVV and LVEF. Results: Mean LVEF measured with N-13-NH3 was 45.6+/-8.9 and 75.3+/-9.4%, mean ESV was 0.40+/-0.12 and 0.14+/-0.11 ml, and mean EDV was 0.53+/-16 and 0.75+/-0.18 ml for MI and control rats, respectively. Moderate to good correlations were observed between values of N-13-NH3 and F-18-FDG for calculation of ESV [r=0.80, P Conclusion: Correlations were moderate to good for the assessment of ESV, EDV and LVEF between gated N-13-NH3 and F-18-FDG. LVEF was underestimated with gated N-13-NH3 in rats with myocardial infarction. in healthy rats, LV volumes and LVEF can be measured reproducibly with either approach. (C) 2012 Elsevier Inc. All rights reserved