Radiological Evaluation Criteria for Chronic Subdural Hematomas: Review of the Literature

Background: The methodology of measuring chronic subdural hematoma (cSDH) extent and its effect on intracranial structures is relevant for patient classification and outcome measurements and affects the external validity of cSDH studies. With embolization of the middle meningeal artery (MMA) as a possible treatment of cSDHs, the topic has gained substantial interest. We sought to summarize the heterogeneity of radiologic measurements, specifically in the evaluation of cSDHs based on literature review. Methods: In this review, we identified and described the most common radiological methodologies for measurements of cSDH thickness, cSDH volume and of midline shift. Conclusion: There are numerous published methods on how to evaluate cSDH thickness, cSDH volume and midline shift but no common standard. The definition of measurement methods and reporting standards for MMA embolization in cSDH patients and their validation needs to be addressed.