title: Comparison of 1.0-, 1.5-, and 2.0-pitch abdominal helical computed tomography in evaluation of normal structures and pathologic lesions.
abstract: OBJECTIVE
  The authors performed a comprehensive prospective clinical trial comparing 1.0-, 1.5-, and 2.0-pitch abdominal helical computed tomography (CT) in the evaluation of normal and pathologic structures/lesions.
  
  
  METHODS
  Seventy-five consecutive patients were randomized by computer into one of three equal groups: helical CT pitch 1.0, 1.5, and 2.0. The imaging parameters and contrast enhancement of all 75 patients were kept constant. The 75 studies were masked, placed into a randomized order, and evaluated by five separate experienced radiologists who rated visualization of 25 normal structures and up to five pathologic findings per patient using a scale of 1 (not seen) to 5 (very well seen/very sharp margins).
  
  
  RESULTS
  There were no statistical differences in 1.0- and 1.5-pitch abdominal CT scans when assessing the display of normal and pathologic lesions. In addition, helical pitch 1.0 and 1.5 studies were equivalent for both normal and pathologic structures/lesions, whereas equivalency was not demonstrated for helical pitch 2.0 studies. Overall study assessment questions again found equivalency between helical 1.0- and 1.5-pitch studies.
  
  
  CONCLUSIONS
  Abdominal CT performed with pitches of 1.0 and 1.5 are equivalent. Because of its advantages, we advocate the routine use of an extended pitch (1.5) in routine abdominal CT. Further studies are required to evaluate the usefulness of the helical 2.0-pitch technique.
authors.affiliation: Department of Radiology, Penn State University, Hershey 17033, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Hopper
authors.forename: C J
authors.initials: CJ
authors.lastname: Kasales
authors.forename: R P
authors.initials: RP
authors.lastname: Mahraj
authors.forename: M B
authors.initials: MB
authors.lastname: Starr
authors.forename: T R
authors.initials: TR
authors.lastname: Tenhave
authors.forename: J A
authors.initials: JA
authors.lastname: Jozefiak
authors.forename: S V
authors.initials: SV
authors.lastname: Patrone
authors.forename: P S
authors.initials: PS
authors.lastname: Singer
mesh_terms: D003287:Contrast Media; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D008099:Liver / Q000000981:diagnostic imaging; D010179:Pancreas / Q000000981:diagnostic imaging; D011446:Prospective Studies; D011856:Radiographic Image Enhancement / Q000379:methods; D011860:Radiography, Abdominal / Q000379:methods*; D012187:Retroperitoneal Space / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D014652:Vascular Diseases / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media