Assessment of imaging protocol and patient radiation exposure in pediatric computed tomography angiography

Computed tomography angiography (CTA), a noninvasive imaging procedure, is frequently used for the diagnosis of blood vessel diseases. Pediatric patients are more sensitive to radiation than adults due to their rapidly dividing cells and long life expectancy. Thus, evaluation of pediatric exposure is crucial to ensure that the procedure is justified and the practice is optimized. The objectives of this study were to evaluate pediatric patients' exposure and imaging protocols for different CTA procedures and to estimate the cancer risk incidence. A total of 147 pediatric CTA procedures were performed at King Fahad Medical City using three CT machines (Philips Brilliance CT- 64-slice scanner, Siemens Somatom Definition Flash dual source 128 CT slice scanner and GE 750 HD DISCOVERY dual energy 64 CT slice scanner). The image protocol and patient safety measures were evaluated according to American College of Radiology (ACR) criteria. The Ethics and Research Committee approved the study and informed consent was obtained from children's parents. The mean, standard deviation (sd) and range of patients weight (kg) was 8.1 +/- 13.2 (3.5-58.7). The mean, sd, median and range of patient dose (mGy.cm) for circle of willis, carotid arteries, thoracic and abdominal aorta, heart and vessels, renal artery, pulmonary artery, abdominal aorta, thoracic aorta, upper lim and lower limb were 992 798, 759.0 (204-2829), 285 +/- 157, 660.0 (56.7-652), 500 +/- 457, 210.1 (112-1387), 472 +/- 317, 411.4, (175-3909) and 350 +/- 346, 589.7 (284-1431), respectively. Pediatric average radiation cancer risk incidence was 36 x 10(-4). Patients' doses showed wide variation among the three CT machines and even for the same machine and the same clinical investigation. The dose per procedure is higher compared to previous studies, suggesting that the dose is not yet optimized. Protection of radiosensitive organs is highly recommended for pediatric patients.