Pediatric 64-MDCT coronary angiography with ECG-modulated tube current: radiation dose and cancer risk.
OBJECTIVE
The purpose of our study was to measure the radiation dose from ECG-gated CT coronary angiography in children and to estimate the cancer risk associated with the radiation dose.


METHODS
Organ doses were measured with a 5-year-old pediatric phantom and thermoluminescent dosimeters on a 64-MDCT scanner. Four retrospectively ECG-gated CT coronary angiography protocols with four simulated heart rates and the corresponding pitches were studied. The lifetime attributable risk of cancer incidence was estimated for children in the United States and Hong Kong according to the National Academies Biologic Effects of Ionizing Radiation VII report.


RESULTS
The effective doses were 16.45, 12.17, 11.97, and 11.81 mSv for the four protocols, respectively. The corresponding lifetime attributable risks estimated for 5-year-old U.S. boys and girls were 0.14%-0.20% and 0.43%-0.60%, respectively, and for 5-year-old Hong Kong boys and girls were 0.22%-0.33% and 0.61%-0.85%. In relation to the total cancer incidence (baseline cancer incidence plus lifetime attributable risk), lifetime attributable risk from radiation exposure contributed up to 0.99% and 3.51% for Hong Kong boys and girls and up to 0.46% and 1.57% for U.S. boys and girls.


CONCLUSIONS
Our results suggest that radiation dose and cancer risk of CT coronary angiography to pediatric patients are not negligible, more so in Hong Kong children than in U.S. children. Therefore, these examinations should be well justified clinically.
Huang
Bingsheng
B
Department of Diagnostic Radiology, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Rd., Hong Kong.
Law
Martin Wai-Ming
MW
Mak
Henry Ka-Fung
HK
Kwok
Stephen Ping-Fai
SP
Khong
Pek-Lan
PL
D001822:Body Burden; D002648:Child; D002675:Child, Preschool; D017023:Coronary Angiography / Q000379:methods* / Q000706:statistics & numerical data*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008955:Models, Cardiovascular; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D012189:Retrospective Studies; D018570:Risk Assessment; D014481:United States / Q000453:epidemiology