Incidental MRI Signs of Raised Intracranial Hypertension and Its Association with Papilledema in Outpatients Undergoing Brain Imaging

Abstract

Background: While the incidental detection of idiopathic intracranial hypertension (IIH) imaging findings is common during brain MRIs, the existing literature dedicated to the neuroimaging relevance remains limited. Objectives: This study aims to determine the prevalence and clinical significance of incidental MRI indicators suggestive of raised intracranial hypertension in outpatients undergoing brain imaging, with a particular focus on their association with papilledema. Methods: This prospective cohort study was conducted at an academic hospital's radiology department between 2020 and 2022. A total of 178 adult patients referred for outpatient brain MRI participated in the study. MRIs were conducted with established protocols and criteria utilized for identifying IIH radiographic signs. Ocular fundoscopy was performed as part of the examination protocol. A comparison was then made between imaging findings in two groups of patients with and without papilledema. Results: The MRI assessments revealed that 73.5% of patients (n = 131) exhibited at least one indication of IIH, with 4.24% showing at least four signs. The prevalence of papilledema varied, ranging from 2.8% in cases with at least one MRI sign of IIH to 40.0% in those displaying at least four signs. Papilledema demonstrated a significant correlation with prominent Meckel caves and optic nerve tortuosity. Conversely, other imaging findings exhibited negligible associations. A notable correlation was identified between the presence of papilledema and the quantity of IIH indicators detected in brain MRIs. Notably, when three or more MRI features associated with IIH were present, a statistically significant correlation with papilledema emerged. Conclusions: The MRI results in this study frequently revealed indications of IIH, whereas occurrences of papilledema were infrequent. In cases where there are no alarming symptoms or the presence of papilledema, invasive procedures may not be deemed necessary for patients incidentally diagnosed with IIH.