Optimization of the left ventricle ejection fraction estimate obtained during cardiac adenosine stress 82Rubidium-PET scanning: impact of different reconstruction protocols

Left ventricular ejection fraction (LVEF) estimation using adenosine stress myocardial perfusion imaging (MPI) can be challenging. The short half-life of adenosine and the guideline-recommended adenosine infusion stop during Rubidium-82 acquisition protocol may affect the accuracy and repeatability of the LVEF measures. This study comprised 25 healthy volunteers (median age 23 years) who underwent repeat myocardial perfusion imaging (MPI) sessions employing Rubidium-82 PET/CT. A guideline-recommended reconstruction protocol was used for both rest and adenosine stress MPI (150-360 s post-radiotracer injection, standard recon ). For the stress MPI protocol, two additional reconstruction protocols were considered; one was employing 60 seconds data (150-210 seconds, short fixed ) and the other a dynamic frame window based on the bolus arrival of Rubidium-82 in the heart until 210 seconds ( x -210 seconds, short individual ). We report rest and stress LVEF, the LVEF reserve, and the LVEF reserve repeatability. Differences in the LVEF assessments were observed between the guideline recommended and alternative reconstruction protocol (LVEF stress MPI: standard recon = 68 ± 7%, short fixed = 71 ± 7% ( P = .08), short individual = 72 ± 7% ( P = .04)), and the LVEF reserve was reduced for the guideline-recommended protocol (standard recon = 7.8 ± 3.5, short fixed = 10.1 ± 3.7, short individual = 10.5 ± 3.6, all P < .001). The best repeatability measures were obtained for the short individual protocol (repeatability: standard recon = 45.3%, short fixed = 41.2%, short individual = 31.7%). We recommend using the short individual reconstruction protocol for improved LVEF repeatability and reserve assessment. Alternatively, in centers with limited technical support we recommend the use of the short fixed protocol.