title: Radiation dose estimation for prospective and retrospective ECG-gated cardiac CT angiography in infants and small children using a 320-MDCT volume scanner.
abstract: OBJECTIVE
  The purpose of this study is to determine patient dose estimates for clinical pediatric cardiac-gated CT angiography (CTA) protocols on a 320-MDCT volume scanner.
  
  
  METHODS
  Organ doses were measured using 20 metal oxide semiconductor field effect transistor (MOSFET) dosimeters. Radiation dose was estimated for volumetrically acquired clinical pediatric prospectively and retrospectively ECG-gated cardiac CTA protocols in 5-year-old and 1-year-old anthropomorphic phantoms on a 320-MDCT scanner. Simulated heart rates of 60 beats/min (5-year-old phantom) and 120 beats/min (1- and 5-year-old phantoms) were used. Effective doses (EDs) were calculated using average measured organ doses and International Commission on Radiological Protection 103 tissue-weighting factors. Dose-length product (DLP) was recorded for each examination and was used to develop dose conversion factors for pediatric cardiac examinations acquired with volume scan mode. DLP was also used to estimate ED according to recently published dose conversion factors for pediatric helical chest examinations. Repeated measures and paired Student t test analyses were performed.
  
  
  RESULTS
  For the 5-year-old phantom, at 60 beats/min, EDs ranged from 1.2 mSv for a prospectively gated examination to 4.5 mSv for a retrospectively gated examination. For the 5-year-old phantom, at 120 beats/min, EDs ranged from 3.0 mSv for a prospectively gated examination to 4.9 mSv for a retrospectively gated examination. For the 1-year-old phantom, at 120 beats/min, EDs ranged from 2.7 mSv for a prospectively gated examination to 4.5 mSv for a retrospectively gated examination.
  
  
  CONCLUSIONS
  EDs for 320-MDCT volumetrically acquired ECG-gated pediatric cardiac CTA are lower than those published for conventional 16- and 64-MDCT scanners.
authors.affiliation: Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, MLC 5031, Cincinnati, OH 45229, USA. daniel.podberesky@cchmc.org
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Podberesky
authors.forename: Erin
authors.initials: E
authors.lastname: Angel
authors.forename: Terry T
authors.initials: TT
authors.lastname: Yoshizumi
authors.forename: Greta
authors.initials: G
authors.lastname: Toncheva
authors.forename: Shelia R
authors.initials: SR
authors.lastname: Salisbury
authors.forename: Christopher
authors.initials: C
authors.lastname: Alsip
authors.forename: Alessandra
authors.initials: A
authors.lastname: Barelli
authors.forename: John C
authors.initials: JC
authors.lastname: Egelhoff
authors.forename: Colin
authors.initials: C
authors.lastname: Anderson-Evans
authors.forename: Giao B
authors.initials: GB
authors.lastname: Nguyen
authors.forename: David
authors.initials: D
authors.lastname: Dow
authors.forename: Donald P
authors.initials: DP
authors.lastname: Frush
mesh_terms: D001822:Body Burden; D002138:Calibration; D055424:Cardiac-Gated Imaging Techniques; D002675:Child, Preschool; D017023:Coronary Angiography / Q000379:methods*; D006801:Humans; D007223:Infant; D019047:Phantoms, Imaging; D011446:Prospective Studies; D011829:Radiation Dosage; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*