A Preliminary Study of Personalized Head CT Examination in Pediatric

Background: Same head CT examination protocol was employed for pediatric patients who’s skull sizes are different , this could be excessive radiation doses because they usually have smaller head circumference. In our study, we investigate if mAs according to head circumference(HC) reduce radiation doses of sensitive organs including brain, eye lens and salivary glands, but could keep the image quality. Methods: : 83 pediatric patients were prospectively selected. Without limiting the head circumference, 15 pediatrics were selected as conventional group by random number method and received routine head CT examination protocol (250mAs). Low-dose group including remaining 68 patients were divided into 3 subgroups based on HC: 54.1-57.0cm for group A(200mAs), 51.1-54.0cm for group B(150mAs), 48.1-51.0cm for group C(100mAs). The Image quality was assessed by subjective and objective image score. Radimetrics was used to calculate radiation doses of sensitive- organs. Results: : In the conventional group, pediatric patients with smaller head circumference receive higher radiation doses of sensitive-organs. Radiation doses of brain and salivary glands were negatively correlated with HC. The radiation dose of sensitive-organs in 3 low-dose subgroups were significantly lower than conventional group. The subjective image quality scores in group A and B was no statistical different than conventional group. The SNR of thalamus and centrum ovale in low-dose subgroups were no statistical differences compared with conventional group. Conclusions: : Our research indicates that personalized brain CT examination in pediatrics can reduce the radiation doses of sensitive-organs but keep image quality. HC can serve as an effective index to guide personalized head CT scan.