title: Pediatric chest and abdominopelvic CT: organ dose estimation based on 42 patient models.
abstract: OBJECTIVE
  To estimate organ dose from pediatric chest and abdominopelvic computed tomography (CT) examinations and evaluate the dependency of organ dose coefficients on patient size and CT scanner models.
  
  
  METHODS
  The institutional review board approved this HIPAA-compliant study and did not require informed patient consent. A validated Monte Carlo program was used to perform simulations in 42 pediatric patient models (age range, 0-16 years; weight range, 2-80 kg; 24 boys, 18 girls). Multidetector CT scanners were modeled on those from two commercial manufacturers (LightSpeed VCT, GE Healthcare, Waukesha, Wis; SOMATOM Definition Flash, Siemens Healthcare, Forchheim, Germany). Organ doses were estimated for each patient model for routine chest and abdominopelvic examinations and were normalized by volume CT dose index (CTDI(vol)). The relationships between CTDI(vol)-normalized organ dose coefficients and average patient diameters were evaluated across scanner models.
  
  
  RESULTS
  For organs within the image coverage, CTDI(vol)-normalized organ dose coefficients largely showed a strong exponential relationship with the average patient diameter (R(2) > 0.9). The average percentage differences between the two scanner models were generally within 10%. For distributed organs and organs on the periphery of or outside the image coverage, the differences were generally larger (average, 3%-32%) mainly because of the effect of overranging.
  
  
  CONCLUSIONS
  It is feasible to estimate patient-specific organ dose for a given examination with the knowledge of patient size and the CTDI(vol). These CTDI(vol)-normalized organ dose coefficients enable one to readily estimate patient-specific organ dose for pediatric patients in clinical settings. This dose information, and, as appropriate, attendant risk estimations, can provide more substantive information for the individual patient for both clinical and research applications and can yield more expansive information on dose profiles across patient populations within a practice.
authors.affiliation: From the Department of Radiology, Duke University, 2424 Erwin Rd, Suite 302, Durham, NC 27705.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Tian
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: W Paul
authors.initials: WP
authors.lastname: Segars
authors.forename: Erik K
authors.initials: EK
authors.lastname: Paulson
authors.forename: Donald P
authors.initials: DP
authors.lastname: Frush
authors.forename: Ehsan
authors.initials: E
authors.lastname: Samei
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009010:Monte Carlo Method; D061330:Multidetector Computed Tomography / Q000379:methods*; D011829:Radiation Dosage; D011860:Radiography, Abdominal; D013902:Radiography, Thoracic; D012189:Retrospective Studies