title: Cardiac PET/CT with Rb-82: optimization of image acquisition and reconstruction parameters.
abstract: BACKGROUND
  Our aim was to characterize the influence of time-of-flight (TOF) and point spread function (PSF) recovery corrections, as well as ordered subset expectation maximization (OSEM) reconstruction parameters, in82Rb PET/CT quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR). Rest and stress list-mode dynamic82Rb PET acquisition data from 10 patients without myocardial flow defects and 10 patients with myocardial blood flow defects were reconstructed retrospectively. OSEM reconstructions were performed with Gaussian filters of 4, 6, and 8 mm, different iterations, and subset numbers (2 × 24; 2 × 16; 3 × 16; 4 × 16). Rest and stress global, regional, and segmental MBF and MFR were computed from time activity curves with FlowQuant©software. Left ventricular segmentation using the 17-segment American Heart Association model was obtained.
  
  
  RESULTS
  Whole left ventricle (LV) MBF at rest and stress were 0.97 ± 0.30 and 2.30 ± 1.00 mL/min/g, respectively, and MFR was 2.40 ± 1.13. Concordance was excellent and all reconstruction parameters had no significant impact on MBF, except for the exclusion of TOF which led to significantly decreased concordance in rest and stress MBF in patients with or without perfusion defects on a coronary artery basis and in MFR in patients with perfusion defects.
  
  
  CONCLUSIONS
  Changes in reconstruction parameters in perfusion82Rb PET/CT studies influence quantitative MBF analysis. The inclusion of TOF information in the tomographic reconstructions had significant impact in MBF quantification.
authors.affiliation: Haute École de Santé Vaud - Filière TRM, University of Applied Sciences and Arts Western Switzerland, Lausanne, Switzerland.|Nuclear Medicine and Molecular Imaging Department, Lausanne University Hospital, Lausanne, Switzerland.|Área Científica de Medicina Nuclear, Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Lisbon, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Chilra
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland.|Nuclear Medicine and Molecular Imaging Department, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Gnesin
authors.affiliation: Nuclear Medicine and Molecular Imaging Department, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Allenbach
authors.affiliation: Nuclear Medicine and Molecular Imaging Department, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Monteiro
authors.affiliation: Nuclear Medicine and Molecular Imaging Department, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: J O
authors.initials: JO
authors.lastname: Prior
authors.affiliation: Área Científica de Medicina Nuclear, Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Lisbon, Portugal.|Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Vieira
authors.affiliation: Haute École de Santé Vaud - Filière TRM, University of Applied Sciences and Arts Western Switzerland, Lausanne, Switzerland. jose.jorge@hesav.ch.
authors.forename: J A
authors.initials: JA
authors.lastname: Pires Jorge
keywords: Cardiac PET/CT reconstruction; Myocardial blood flow; Myocardial flow reserve; Rb-82