Establishment of a normal control model of children’s brain 18-fluorodeoxyglucose positron emission tomography and analysis of the changing pattern in patients aged 0–14 years

Abstract

Background It is difficult to obtain 18-fluorodeoxyglucose positron emission tomography ( 18 FDG-PET) data from normal children, and changes in brain metabolism in children due to growth and development are poorly understood. For the first time, we established a normal control model of brain 18 FDG-PET in children and evaluated its feasibility. The association of PET with age in children aged 0–14 years was analyzed. This study aimed to establish a normal control model of brain 18 FDG-PET in children for the first time and to verify its feasibility, and to analyze the trend of PET with age in children aged 0–14 years. Methods In this retrospective cohort study, the 18 FDG-PET imaging data of patients with no epileptiform discharge involvement contralateral to the epileptogenic zone were consecutively collected from January 2015 to June 2022 according to strictly defined screening criteria. For the normal control data, the hemisphere contralateral to the epileptogenic zone was mirrored and spliced to form an intact brain. The cohort of children aged 0–14 years was divided into 14 groups according age by year. Subsequently, patients who underwent lesionectomy with clear hypometabolism that roughly coincided with the extent of surgical resection were examined. The PET scan was compared with the control model, and the ratio of overlapping parts (hypometabolic areas ∩ surgical resection area) to hypometabolic parts (ROH) was calculated. Multiple regression analysis was performed on the normal control model for every 3- to 4-year age interval. Results A total of 159 normal control models were established. Five patients were randomly selected to verify the reliability of each yearly model. The average ROH was 0.968. Metabolism increasing with age in the different brain regions was observed at ages 0–2~, 3–5~, and 6–10 years. No age-related metabolic increase or decrease was found in the 10- to 14-year-old group. The metabolism in the 7- to 8-year-old group was higher than that in the 13- to 14-year-old group. Conclusions With strict screening criteria, the method of mirroring the contralateral hemisphere of the epileptic zone and splicing it into a complete brain as a means of creating a normal control group is feasible. The method offers convenience to the studies that lack healthy pediatric controls. Children under 10 years of age (especially 0–6 years old) experience considerable metabolic changes year on year. After the age of 10 years, the changes in metabolism gradually decrease, and metabolism also slowly decreases. Our findings provide guidance the clinical interpretation of areas with hypometabolism and emphasize the importance of establishing a normal control model of the child’s brain, which should not be replaced by an adult model.