title: A new respiratory gating device to improve 4D PET/CT.
abstract: OBJECTIVE
  Respiratory motion creates artifacts in positon emission tomography with computed tomography (PET/CT) images especially for lung tumors, and can alter diagnosis. To account for motion effects, respiratory gating techniques have been developed. However, the lack of measures strongly correlated with tumor motion limits their accuracy. The authors developed a real-time pneumotachograph device (SPI) allowing to sort PET and CT images depending on lung volumes.
  
  
  METHODS
  The performance of this innovative respiratory tracking system was characterized and compared to a standard system. Our experimental setup consisted in a movable platform and a thorax phantom with six fillable spheres simulating lung tumors. The accuracy of SPI to detect inhalation peaks was also determined on volunteers. A comparison with the real-time position management (RPM) device, that relies on abdominal height measurement, was then investigated.
  
  
  RESULTS
  Experiments showed a high accuracy of the measured signal compared to the input signal (R = 0.88 to 0.99), and of the detection of the inhalation peaks (error of 0.1 +/- 5.8 ms) necessary for prospective binning mode. Activity recovery coefficient was improved (until +39%) and the smearing effect was reduced (until 2.74 times lower) with SPI compared to ungated PET/CT acquisition. The spatial distribution of activity in spheres was similar for 4D PET gated with SPI and RPM. Significant improvement of the binning stability and matching between PET and CT were highlighted for irregular breathing patterns with SPI.
  
  
  CONCLUSIONS
  SPI is an innovative device that provides better binning performance than the current gating device on phantom experiments. Future works will focus on patients where the authors expect a significant improvement of specificity and sensitivity of PET/CT examinations.
authors: SIMAD, LU50, Université Paul Sabatier Toulouse III, 31052 Toulouse, France. didierlaurent.david@claudiusregaud.fr
authors: David
authors: D
authors: Didierlaurent
authors: Sophie
authors: S
authors: Ribes
authors: Olivier
authors: O
authors: Caselles
authors: Cyril
authors: C
authors: Jaudet
authors: Jean-Marc
authors: JM
authors: Cazalet
authors: Hadj
authors: H
authors: Batatia
authors: Frédéric
authors: F
authors: Courbon
mesh_terms: D016477:Artifacts; D056973:Four-Dimensional Computed Tomography / Q000295:instrumentation*; D006801:Humans; D009068:Movement; D064847:Multimodal Imaging / Q000295:instrumentation*; D056888:Patient Positioning; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography; D055425:Respiratory-Gated Imaging Techniques / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed