Neurofibromatosis Type 1: An Imaging Review of Multisystem Manifestations in Children.

Neurofibromatosis type 1 (NF1) is a common inherited tumor predisposition syndrome with multisystem involvement of the central and peripheral nervous systems, vasculature, skeleton, skin, and internal organs. Many clinically relevant manifestations are internal, age-dependent, progressive, or initially asymptomatic, making imaging central to diagnosis, surveillance, and treatment. This review provides a radiology-centered overview of the major imaging manifestations of NF1 and emphasizes pattern recognition, modality selection, and imaging features that should prompt closer follow-up, functional imaging, or tissue diagnosis with a focus on the pediatric population. The review covers optic pathway and non-optic gliomas, plexiform neurofibromas, malignant peripheral nerve sheath tumors, abdominal neoplasms, focal areas of signal intensity/unidentified bright objects (FASIs/UBOs), NF1-associated vasculopathy, and musculoskeletal dysplasias. MRI is the primary modality for evaluating CNS tumors, FASIs/UBOs, plexiform neurofibromas, spinal and paraspinal disease, dural ectasia, and whole-body tumor burden. Diffusion-weighted imaging and Fluordesoxyglucose (FDG)-PET/MRI provide complementary information when malignant transformation of a plexiform neurofibroma is suspected. CT, CTA, MRA, ultrasound, radiography, and catheter angiography remain important in selected settings, particularly for skeletal dysplasia, intracranial and systemic vasculopathy, renovascular hypertension, and preoperative planning. NF1 imaging requires an integrated multisystem approach rather than isolated organ-based interpretation. Careful assessment of lesion morphology, anatomic distribution, interval change, and clinical context enables clinicians to distinguish typical benign manifestations from findings suggestive of progression, malignant transformation, or clinically relevant vascular and skeletal complications.