PT - JOURNAL ARTICLE AU - N. Hainc AU - M.W. Wagner AU - S. Laughlin AU - J. Rutka AU - C. Hawkins AU - S. Blaser AU - B.B. Ertl-Wagner TI - Longitudinal Assessment of Enhancing Foci of Abnormal Signal Intensity in Neurofibromatosis Type 1 AID - 10.3174/ajnr.A6974 DP - 2021 Feb 04 TA - American Journal of Neuroradiology 4099 - http://www.ajnr.org/content/early/2021/02/04/ajnr.A6974.short 4100 - http://www.ajnr.org/content/early/2021/02/04/ajnr.A6974.full AB - BACKGROUND AND PURPOSE: Patients with neurofibromatosis 1 are at increased risk of developing brain tumors, and differentiation from contrast-enhancing foci of abnormal signal intensity can be challenging. We aimed to longitudinally characterize rare, enhancing foci of abnormal signal intensity based on location and demographics.MATERIALS AND METHODS: A total of 109 MR imaging datasets from 19 consecutive patients (7 male; mean age, 8.6 years; range, 2.3–16.8 years) with neurofibromatosis 1 and a total of 23 contrast-enhancing parenchymal lesions initially classified as foci of abnormal signal intensity were included. The mean follow-up period was 6.5 years (range, 1–13.8 years). Enhancing foci of abnormal signal intensity were followed up with respect to presence, location, and volume. Linear regression analysis was performed.RESULTS: Location, mean peak volume, and decrease in enhancing volume over time of the 23 lesions were as follows: 10 splenium of the corpus callosum (295 mm3, 5 decreasing, 3 completely resolving, 2 surgical intervention for change in imaging appearance later confirmed to be gangliocytoma and astrocytoma WHO II), 1 body of the corpus callosum (44 mm3, decreasing), 2 frontal lobe white matter (32 mm3, 1 completely resolving), 3 globus pallidus (50 mm3, all completely resolving), 6 cerebellum (206 mm3, 3 decreasing, 1 completely resolving), and 1 midbrain (34 mm3). On average, splenium lesions began to decrease in size at 12.2 years, posterior fossa lesions at 17.1 years, and other locations at 9.4 years of age.CONCLUSIONS: Albeit very rare, contrast-enhancing lesions in patients with neurofibromatosis 1 may regress over time. Follow-up MR imaging aids in ascertaining regression. The development of atypical features should prompt further evaluation for underlying tumors.FASIfocus of abnormal signal intensityNF-1neurofibromatosis type 1CEcontrast-enhanced