title: Optimum emission time in deep-inspiration breath-hold PET-CT: a preliminary result.
abstract: OBJECTIVE
  The purpose of this study was to investigate optimum emission time of deep inspiration breath-hold (DIBH) positron emission tomography-computed tomography (PET-CT).
  
  
  METHODS
  We collected 15 PET-CT data sets by adding data of every 10 s and acquisition time ranging from 10 s (1 x 10 s acquisition) to 150 s (15 x 10 s acquisition) for both of DIBH mode and free-breathing condition (continuous mode) in phantom study. The coefficient of variation (CV) of radioactivity concentration was compared to determine optimum emission time of PET-CT. We also compared images of DIBH mode and continuous mode to clarify the influence of diaphragmatic movement in clinical setting.
  
  
  RESULTS
  The mean +/- SD of CV in DIBH mode was 1236.3 +/- 323.1. When compared with the CV at 120 s, the relative error of CV is within 10% at 110 s (0.204), 15% at 100 s (0.212), and 20% at 90 s (0.222), respectively. Optimum emission time greater than 90 s is required to obtain clinically available images in DIBH mode. In the clinical setting, the SUV of the lung base and measurements of uptake show little influence by respiration on DIBH PET-CT.
  
  
  CONCLUSIONS
  Optimum emission time of DIBH technique greater than 90 s acquisition is preferable for clinical use.
authors.affiliation: Department of Radiology, Yokohama City University Graduate School of Medicine, Kanazawa-ku, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Miyashita
authors.forename: Ukihide
authors.initials: U
authors.lastname: Tateishi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nishiyama
authors.forename: Ryogo
authors.initials: R
authors.lastname: Minamimoto
authors.forename: Kazuya
authors.initials: K
authors.lastname: Shizukuishi
authors.forename: Tomio
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D001239:Inhalation; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*