title: Dose and pitch relationship for a particular multislice CT scanner.
abstract: OBJECTIVE
  With single-slice helical CT, an increased pitch can decrease the radiation dose to the patient if all other parameters are constant. The purpose of this study was to determine whether the same relationship holds for a particular multislice helical CT system (Somatom Plus 4 VZ multislice helical CT scanner, version A11A) in our department.
  
  
  CONCLUSIONS
  The measured radiation dose to the phantom was identical for all pitch selections on the multislice helical CT system we tested. This unexpected result was because of an automatic proportionate increase in the tube current when the pitch selection was increased. Radiologists and physicists should exercise caution when extrapolating dose reduction strategies from single-slice to multislice helical CT systems, and they must acquire a detailed understanding of the multislice helical CT scanner of their chosen manufacturer.
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 601 N. Caroline St, Baltimore, MD 21287-0811, USA.
authors.forename: M
authors.initials: M
authors.lastname: Mahesh
authors.forename: J C
authors.initials: JC
authors.lastname: Scatarige
authors.forename: J
authors.initials: J
authors.lastname: Cooper
authors.forename: E K
authors.initials: EK
authors.lastname: Fishman
mesh_terms: D004867:Equipment Design; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*