Quantitative Analysis of the Clinical Reasons Influencing the Frequency of Pediatric Head CT Examinations: A Single-Center Observation Study.

Epidemiological studies on radiation exposure from pediatric CT scans have attracted attention in terms of radiological protection. These studies have not taken into account the reasons why CT examinations were performed. It is presumed that there are clinical reasons that justify more frequent CT examinations in children. The purpose of this study was to characterize the clinical reasons why relatively high numbers of head CT examinations (NHCT) are frequently performed and to conduct a statistical analysis to determine the factors governing the NHCT. Patient information, the date of examination, and medical conditions for examination data stored on the radiology information system were used to investigate the reasons for undergoing CT examinations. The target facility was National Children's Hospital; data were obtained from March 2002 to April 2017, and the age of the study population was less than 16 years old. Quantitative analysis of the factors associated with frequent examinations was conducted by Poisson regression analysis. Among all patients who had a CT scan, 76.6% had head CT examinations, and 43.4% of children were under 1 year old at the time of the initial examination. There were marked differences in the number of examinations depending on the disease. The average NHCT was higher for children younger than 5 days of age. Among children less than 1 year of age with surgery, there was a marked difference between hydrocephalus, with a mean = 15.5 (95% CI 14.3,16.8), and trauma, with a mean = 8.3 (95% CI 7.2,9.4). In conclusion, this study revealed that NHCT was significantly higher in children who had undergone surgery than in those who had not been to the hospital. The clinical reasons behind patients with higher NHCT should be considered in investigating a causal relationship between CT exposure and brain tumors.