title: Derivation of a respiration trigger signal in small animal list-mode PET based on respiration-induced variations of the ECG signal.
abstract: BACKGROUND
  Raw PET list-mode data contains motion artifacts causing image blurring and decreased spatial resolution. Unless corrected, this leads to underestimation of the tracer uptake and overestimation of the lesion size, as well as inaccuracies with regard to left ventricular volume and ejection fraction (LVEF), especially in small animal imaging.
  
  
  RESULTS
  A respiratory trigger signal from respiration-induced variations in the electro-cardiogram (ECG) was detected. Original and revised list-mode PET data were used for calculation of left ventricular function parameters using both respiratory gating techniques. For adequately triggered datasets we saw no difference in mean respiratory cycle period between the reference standard (RRS) and the ECG-based (ERS) methods (1120 ± 159 ms vs 1120 ± 159 ms; P = n.s.). While the ECG-based method showed somewhat higher signal noise (66 ± 22 ms vs 51 ± 29 ms; P < .001), both respiratory triggering techniques yielded similar estimates for EDV, ESV, LVEF (RRS: 387 ± 56 µL, 162 ± 34 µL, 59 ± 5%; ERS: 389 ± 59 µL, 163 ± 35 µL, 59 ± 4%; P = n.s.).
  
  
  CONCLUSIONS
  This study showed that respiratory gating signals can be accurately derived from cardiac trigger information alone, without the additional requirement for dedicated measurement of the respiratory motion in rats.
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany. andrei.todica@med.uni-muenchen.de.
authors.forename: Andrei
authors.initials: A
authors.lastname: Todica
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lehner
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.
authors.forename: Mathias J
authors.initials: MJ
authors.lastname: Zacherl
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Nekolla
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.
authors.forename: Erik
authors.initials: E
authors.lastname: Mille
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.|German Center for Vertigo and Balance Disorders, DSGZ, University of Munich, Munich, Germany.
authors.forename: Guoming
authors.initials: G
authors.lastname: Xiong
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bartenstein
authors.affiliation: Department of Clinical Molecular Imaging and Nuclear Medicine, University Hospital Tübingen, Tübingen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: la Fougère
authors.affiliation: Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University Vienna, Vienna, Austria.
authors.forename: Marcus
authors.initials: M
authors.lastname: Hacker
authors.affiliation: Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Böning
mesh_terms: D000465:Algorithms; D000818:Animals; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods / Q000662:veterinary*; D004562:Electrocardiography / Q000379:methods / Q000662:veterinary*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D007089:Image Enhancement / Q000379:methods; D010363:Pattern Recognition, Automated / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods / Q000662:veterinary*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods / Q000662:veterinary*; D012680:Sensitivity and Specificity; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: FDG PET; left ventricular function; myocardium; rat; respiratory gating