Hyperdense Capsule Sign at Noncontrast CT as an Indication for Middle Meningeal Artery Embolization for Nonacute Subdural Hematomas: A MAGIC-MT Trial Post Hoc Analysis
In brief
MMA embolization halves recurrence in subdural hematomas showing hyperdense capsule
In a post-hoc analysis of 697 patients with non-acute subdural hematoma, those whose CT scans displayed a hyperdense capsule sign had a recurrence or progression rate of 5% after middle meningeal artery embolization versus 12% with usual care-a roughly 50% reduction. The benefit was not seen in patients without the sign, suggesting the CT feature may help select candidates for embolization, though further validation is needed.
- Journal
- Radiology (Q1)
- Published
- 1 July 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Ruiyuan Weng, Jiabin Su, Shengjun Zhou, Heng Yang, Hanqiang Jiang, Xinjie Gao, et al.
- PMID
- 42411965
- DOI
- 10.1148/radiol.251512
Why clinicians should know about it
- Picked for Radiology, Radiation Oncology, Nuclear Medicine, Medical Physics and Imaging (top studies of the week, 8 November 2026): HDCS on CT predicts benefit from MMA embolization
Abstract
Background Hematoma recurrence and progression remain common challenges in nonacute subdural hematomas (SDHs). The understanding of indications for middle meningeal artery embolization (MMAE) is limited. Purpose To investigate the utility of the hyperdense capsule sign (HDCS) at noncontrast CT for identifying potential candidates for MMAE for nonacute SDH. Materials and Methods In this post hoc analysis of the MAGIC-MT randomized controlled trial (September 2022 to December 2023) comparing adjunctive MMAE and usual care, participants were grouped by HDCS presence or absence at noncontrast CT. The primary outcome was symptomatic recurrence or progression of SDH. The Cochran-Mantel-Haenszel χ2 test, propensity score matching (PSM), multivariable analysis, and P value for interaction were used for subgroup comparisons. Results Among 697 participants included in this analysis (median age, 69 years [IQR, 61-74 years]; 575 male participants), 444 (63.7%) showed HDCS presence. Primary outcome incidence was lower in the embolization versus usual-care group among participants with the HDCS (5.0% vs 12.0%, P = .009; after PSM: 4.1% vs 11.2%, P = .04) but not among those without the HDCS (9.4% vs 5.6%, P = .24; after PSM: 10.3% vs 5.0%, P = .13), with an interaction between MMAE and HDCS presence (P = .01; after PSM: P = .01). The proportion of participants experiencing a serious adverse event was lower in the embolization versus usual-care group among those with the HDCS (5.9% vs 15.1%, P = .002; after PSM: 5.8% vs 15.5%, P = .02) but not among those without the HDCS (8.7% vs 5.6%, P = .34; after PSM: 9.4% vs 5.8%, P = .30), with a significant interaction (P = .01; after PSM: P = .02). Conclusion For participants with nonacute SDH, the presence of the HDCS was associated with a lower rate of recurrence or progression among those who underwent MMAE compared with those receiving usual care. HDCS may potentially help identify candidates for MMAE for nonacute SDH. Clinical trial registration no. NCT04700345 © RSNA, 2026 Supplemental material is available for this article. See also the editorial by Kallmes in this issue.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.