Can T2 blackout effect be a marker of iron accumulation in brains of multiple sclerosis patients?

Abstract

T2 blackout (TBO) effect, which is a common finding in the brains of multiple sclerosis (MS) patients and older population that are imaged for other reasons on diffusion weighted imagings (DWI) and apparent diffusion coefficient (ADC) map show the existence of paramagnetic materials in the tissue. Because iron is known to accumulate in especially deep gray matter (DGM) structures in MS brains, we aimed to investigate the relationship between TBO and clinico-radiological parameters that may be iron-related in MS. We retrospectively reviewed the latest MR images of MS patients on 3 Tesla MR scanner between 2018 and 2019. TBO existence and severity on DWI-ADC was assessed by two radiologists and its correlation with several outcomes of MS was investigated. No significant relationship was found between TBO and gender, subtype of MS whereas TBO was positively correlated with parameters such as black-hole lesions, cortical atrophy, duration of disease, age and extended disability status scale (EDSS) score. TBO shows correlation with the conditions which were revealed to be associated with iron accumulation in the brain of MS patients in the literature. Therefore, we concluded that TBO and its severity in DGM may represent iron accumulation in MS brains. TBO effect as a frequent imaging finding in daily practice may be used as predictor of the disease course of MS due to possible effects of iron accumulation in brain and thereby may be useful in modifying treatment strategies.