PET/MRI in Pediatric Neuroimaging: Primer for Clinical Practice

Abstract

Modern pediatric imaging seeks to provide not only exceptional anatomic detail but also physiologic and metabolic information of the pathology in question with as little radiation penalty as possible. Hybrid PET/MR imaging combines exquisite soft-tissue information obtained by MR imaging with functional information provided by PET, including metabolic markers, receptor binding, perfusion, and neurotransmitter release data. In pediatric neuro-oncology, PET/MR imaging is, in many ways, ideal for follow-up compared with PET/CT, given the superiority of MR imaging in neuroimaging compared with CT and the lower radiation dose, which is relevant in serial imaging and long-term follow-up of pediatric patients. In addition, although MR imaging is the main imaging technique for the evaluation of spinal pathology, PET/MR imaging may provide useful information in several clinical scenarios, including tumor staging and follow-up, treatment response assessment of spinal malignancies, and vertebral osteomyelitis. This review article covers neuropediatric applications of PET/MR imaging in addition to considerations regarding radiopharmaceuticals, imaging protocols, and current challenges to clinical implementation.

FIGURE.

Diffuse astrocytoma in 4-year-old child demonstrates a nonenhancing FLAIR hyperintense mass involving the gray and white matter of the left frontal lobe (A and B). There is no evidence of reduced diffusion or hypointense signal on ADC (C and D). The inferior aspect of the lesion demonstrates a subtle decrease in FDG uptake compared with the contralateral side (E), while the superior portion demonstrates relative hypermetabolism on FDG-PET (F).