Computer-simulated radiation dose reduction for abdominal multidetector CT of pediatric patients.
OBJECTIVE
Limiting CT radiation dose is especially critical when imaging children. The purpose of our study was to modify and test an accurate and safe tool for evaluating systematic dose reduction for abdominal multidetector CT (MDCT) in pediatric patients.


METHODS
After validating the computer-simulation technique with a water phantom, we subjected the original digital scanning data for 26 contrast-enhanced abdominal MDCT scans (120 mA) obtained in infants and children (age range, 1 month-9 years; mean age, 3.1 years) to simulated tube current reduction (100, 80, 60, and 40 mA) by adding noise. this procedure created four additional examinations per child that were identical to the originals except for image noise. The 130 examinations were scored randomly, independently, and without prior knowledge of the children's diagnoses by three radiologists for depiction of high-visibility structures, such as adrenal glands and fat in the intrahepatic falciform ligament, and low-visibility structures, such as the extrahepatic hepatic artery, small intrahepatic vessels, and common bile duct. Aligned rank and Wilcoxon's signed rank tests were used for statistical analyses.


RESULTS
Simulated tube current reduction significantly affected the detection of low-visibility structures (p < 0.001). Reduced detection in low-visibility structures was evident at a level less than or equal to 80 mA. No loss of detection in high-visibility structures was found at any tube current level (p > 0.5).


CONCLUSIONS
The results of this computer simulation suggest that accurate abdominal MDCT can be performed in pediatric patients using substantially reduced radiation, depending on the indication for imaging. (In our case, the reduction was between 33% and 67%, depending on whether a high-visibility or low-visibility structure was being assessed.) This simulation technology can be applied to MDCT of other organ systems for systematic evaluation of radiation dose reduction.
Frush
Donald P
DP
Division of Pediatric Radiology, 1905 McGovern-Davison Children's Health Center, Box 3808, Department of Radiology, Duke University Medical Center, Erwin Rd., Durham, NC 22710, USA.
Slack
Christopher C
CC
Hollingsworth
Caroline L
CL
Bisset
George S
GS
Donnelly
Lane F
LF
Hsieh
Jiang
J
Lavin-Wensell
Trudy
T
Mayo
John R
JR
D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D003287:Contrast Media; D006801:Humans; D007223:Infant; D010372:Pediatrics; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011860:Radiography, Abdominal; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed
D003287:Contrast Media