Comparison of brain F-18 FDG PET/MRI with PET/CT imaging in pediatric patients

Standardized uptake values (SUVs) are important indexes for evaluating the accuracy of disease diagnoses achieved via fluoro-18 deoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance imaging (PET/MRI). The purpose of this study is to describe normal cerebral FDG uptake in the pediatric population and compare SUVmax/mean results for brain images obtained from PET/CT and PET/MRI in neurologically healthy pediatric examinees.

This study included 20 patients who were < 18 years of age and were without intracranial malignancy and/or brain disorders. Patients underwent either PET/CT imaging (n = 10) or PET/MRI imaging (n = 10) after 70-80 min of F-18 FDG injection. The SUVmax and SUVmean for various brain regions were calculated and compared between sides and imaging modalities using with appropriate statistical tests.

The median SUVmax/SUVmean values of the right-sided frontal, parietal, temporal, and occipital lobes were 8.63/ 6.18, 8.85 / 6.97, 6.88 / 4.99, and 11.06 / 7.02 in PET/CT, respectively, and 11.45 / 8.59, 10.16 / 8.47, 8.82 / 6.6, and 11.71 / 8.25 in PET/MRI, respectively. The median SUVmax/SUVmean values of the left-sided frontal, parietal, temporal, and occipital lobes were 9.05 / 6.86, 8.03 / 6.62, 6.49 / 4.77, and 10.6 / 7.73 in PET/CT, respectively, and 10.7 / 8.16, 11.06 / 7.88, 8.13 / 6.09, and 10.96 / 9.22 in PET/MRI, respectively.

These results showed that there was no statistically significant difference in SUVs values between the two brain imaging modalities except from SUVmax value of left-sided parietal lobe and no asymmetric radiopharmaceutical uptake between the left and right brain regions or cerebellums in each modality, suggested that in brain imaging, PET/MRI can be used reliably instead of PET/CT.