Neurofibroma MRI

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2] Shanshan Cen, M.D. [3]

Overview

MRI may be helpful in the diagnosis of neurofibroma. It appears as a hypointense, homogeneous low signal intensity lesion with center demonstrating a higher signal intensity than the periphery on T1. T2 weighted images show hyperintense, homogeneous lesion with positive target sign and fascicular sign. Moreover, neurofibromas have heterogeneous enhancement on T1 C+ (Gd) (with gadolinium contrast).


MRI sequence	Characteristics
T1	Hypointense Homogeneous low signal intensity Center demonstrating a higher signal intensity than the periphery (reverse of target sign on T2)
T2	Hyperintense Homogeneous high signal intensity (higher than fat) Target sign (plexiform neurofibromas) Low signal intensity centrally with a ring of high signal intensity peripherally Due to a dense central area of collagenous stroma Highly suggestive of neurofibroma but occasionally also seen in schwannomas and malignant peripheral nerve sheath tumors Fascicular sign Plexiform neurofibromas may appear as a larger and more infiltrating mass with lobulated borders with inhomogeneous enhancement Myxoid stroma enhancement helps differentiating the high signal intensity at T2-weighted imaging from cystic change or necrosis
T1 C+ (Gd) (with gadolinium contrast)	Heterogenous enhancement

↑ Neurofibroma.Dr Bruno Di Muzio and Dr Maxime St-Amant et al. Radiopaedia.org 2015. http://radiopaedia.org/articles/neurofibroma Accessed on November 17, 2015
↑ https://pubs.rsna.org/doi/10.1148/rg.24si035170#REF8