title: Development of variable pitch factor scanning for multislice computed tomography.
abstract: OBJECTIVE
  The latest multislice computed tomography (MSCT) scanners permit the chest and abdomen to be scanned continuously. However, conventionally, it has been necessary to perform scanning twice using different pitch factors for the cardiac and abdominal regions. We have developed a new scanning technique known as variable pitch factor scanning, in which the table speed is changed during scanning to obtain continuous images from the heart to the abdomen in a single scan, and have evaluated its physical characteristics.
  
  
  METHODS
  A bead phantom, a comb phantom, and a gold wire placed at an angle were scanned using a 64-row MSCT scanner. The variation in the spatial resolution and continuity of images in the body axis direction because of changes in the pitch factor were evaluated.
  
  
  RESULTS
  Because reconstruction taking the cone angle into consideration was employed, the spatial resolution in the body axis direction was unchanged and the continuity of images in the body axis direction was maintained at a certain level even when the pitch factor was changed.
  
  
  CONCLUSIONS
  Variable pitch factor scanning is a useful technique for obtaining continuous images from the heart to the abdomen in a single scan.
authors.affiliation: CT Systems Development Department, Toshiba Medical Systems Corporation, Tochigi, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Takamasa
authors.initials: T
authors.lastname: Ota
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Maeda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Noshi
authors.forename: Satoru
authors.initials: S
authors.lastname: Nakanishi
authors.forename: Miwa
authors.initials: M
authors.lastname: Okumura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sanda
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Anno
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Katada
mesh_terms: D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D011860:Radiography, Abdominal / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*