MRI appearance of chronic subdural hematoma

Abstract

ObjectiveWe aimed to describe the magnetic resonance imaging (MRI) characteristics of chronic subdural hematoma (cSDH) and to ascribe MRI patterns.MethodsA total of 20 patients having 27 subdural hematomas underwent contrast-enhanced (CE) MRI of the brain at our institution between April 2019 and May 2021. The images were independently evaluated by two experienced neuroradiologists with regard to imaging characteristics on T1w, T2w, T2*-GRE, FLAIR, diffusion-weighted magnetic resonance imaging (DWI), and CE images.ResultsThe signal characteristics of cSDH on T1- and T2-weighted images were rather heterogeneous. The majority of hematomas (74%) had internal septations. Surprisingly, contrast enhancement along the outer membrane adjacent to the cranium was noticed in all hematomas. There was also contrast enhancement along the inner membrane adjacent to the brain in more than one-third of the hematomas (37%). In approximately two-thirds of the cSDH (62%), there was a mass-like enhancement of the hematoma. Most hematomas (89%) were partially hypointense on T2*-GRE and/or susceptibility-weighted imaging (SWI). Restricted diffusion was detected in approximately one-third of the hematomas (33%).ConclusionConsistent contrast enhancement along the outer membrane, triangular-shaped contrast enhancement at the borders of the cSDH, and infrequent enhancement of the inner membrane may help to distinguish cSDH from other entities such as empyema and tumors. Mass-like enhancement may refer to non-solid hematomas and could be an indicator for hematoma growth and a possible surrogate for successful endovascular embolization. Restricted diffusion in a subdural mass is not specific for empyema but may also be found in cSDH.

The possibility of surgery in chronic subdural hematoma associated with the use of antiplatelet or anticoagulant drugs

“…The following initial CT findings were investigated: initial maximal thickness of subdural hematoma, density type of CSH, location of CSH (bilateral, left, or right), and distance of midline shifting. Density type of CSH was categorized into the following 4 types: homogeneous hypodensity ( < 25 Housefield unit [HU]), homogeneous isodensity (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35), mixed type, and layered type on CT findings (Fig. 1).…”

“…In addition, other studies have shown that the presence of brain atrophy is associated with recurrence because of the presence of a persistent subdural space [15,30]. Furthermore, if there is septation in radiologic findings, recurrence may be caused by a residual hematoma because it is difficult to drain the hematoma completely [29,31,32]. Also, if there is a residual hematoma, a neovascularized membrane develops, and therefore, continuous microbleeding in fragile and leaky vessels can occur, which can lead to hematoma accumulation.…”

Letter to the Editor: Clinical and Radiologic Outcomes of Single Burr Hole Drainage and Mini-craniotomy in the Treatment of Inhomogeneous Chronic Subdural Hematoma: A Retrospective Study (Korean J Neurotrauma 2022;18:208-220)

“…Magnetic resonance imaging (MRI) may provide helpful information for diagnosing multiseptated CSDH. 2) Lee et al 4) reported that diffusion-weighted MRI provides better resolution of multiseptated CSDH and can predict post-treatment failure more accurately than brain CT.…”