Comparison of radiation dose estimates and scan performance in pediatric high-resolution thoracic CT for volumetric 320-detector row, helical 64-detector row, and noncontiguous axial scan acquisitions.
OBJECTIVE
Efforts to decrease radiation exposure during pediatric high-resolution thoracic computed tomography (HRCT), while maintaining diagnostic image quality, are imperative. The objective of this investigation was to compare organ doses and scan performance for pediatric HRCT using volume, helical, and noncontiguous axial acquisitions.


METHODS
Thoracic organ doses were measured using 20 metal oxide semiconductor field-effect transistor dosimeters. Mean and median organ doses and scan durations were determined and compared for three acquisition modes in a 5-year-old anthropomorphic phantom using similar clinical pediatric scan parameters. Image noise was measured and compared in identical regions within the thorax.


RESULTS
There was a significantly lower dose in lung (1.8 vs 2.7 mGy, P < .02) and thymus (2.3 vs 2.7 mGy, P < .02) between volume and noncontiguous axial modes and in lung (1.8 vs 2.3 mGy, P < .02), breast (1.8 vs 2.6 mGy, P < .02), and thymus (2.3 vs 2.4 mGy, P < .02) between volume and helical modes. There was a significantly lower median image noise for volume compared to helical and axial modes in lung (55.6 vs 79.3 and 70.7) and soft tissue (76.0 vs 111.3 and 89.9). Scan times for volume, helical, and noncontiguous axial acquisitions were 0.35, 3.9, and 24.5 seconds, respectively.


CONCLUSIONS
Volumetric HRCT provides an opportunity for thoracic organ dose and image noise reduction, at significantly faster scanning speeds, which may benefit pediatric patients undergoing surveillance studies for diffuse lung disease.
Cincinnati Children's Hospital Medical Center, Department of Radiology, 3333 Burnet Avenue, MLC 5031, OH 45229, USA. daniel.podberesky@cchmc.org
Daniel J
DJ
Podberesky
Erin
E
Angel
Terry T
TT
Yoshizumi
Greta
G
Toncheva
Shelia R
SR
Salisbury
Alan S
AS
Brody
Christopher
C
Alsip
Alessandra
A
Barelli
John C
JC
Egelhoff
Colin
C
Anderson-Evans
Giao B
GB
Nguyen
David
D
Dow
Donald P
DP
Frush
D002675:Child, Preschool; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D014915:Whole-Body Counting
Respiratory system; pediatrics; radiation dosimetry; volumetric computed tomography