Association of Inner Membrane Visibility on Noncontrast CT With Response to Middle Meningeal Artery Embolization in Chronic Subdural Hematoma.

Interrater agreement for noncontrast CT grading was substantial (κ=0.64), and agreement between noncontrast CT- and immediate post-middle meningeal artery embolization CT-based classifications was almost perfect (κ=0.81).

Binary classification of complete versus non-complete visibility also showed almost perfect agreement between noncontrast CT and immediate post-middle meningeal artery embolization CT (κ=0.84).

At 3 months, both absolute and relative hematoma volumes increased stepwise from none to partial to complete visibility (both P<.001).