Diffusion-weighted imaging findings predictive of postoperative recurrence of chronic subdural hematoma.

Objectives: To identify the brain magnetic resonance imaging (MRI) findings associated with the postoperative recurrence of chronic subdural hematoma (CSDH).

Methods: We examined 1099 consecutive patients admitted to our hospital with CSDH between 2005 and 2014. Of those, 1021 who underwent surgery for CSDH and were followed-up for >3 months after surgery were included. Preoperative brain MRI findings were classified as homogeneous, laminar, separate, or trabecular, according to the nature of the hematoma. Postoperative recurrence was defined in patients who required reoperation for ipsilateral hematoma growth within three months of surgery. The clinical and radiological factors associated with postoperative recurrence were evaluated using univariate and multivariate analyses.

Results: Of the 1021 CSDH patients with CSDH who underwent surgery, 91 (8.9%) experienced postoperative recurrence. Postoperative recurrence was significantly associated with male sex (p = 0.0004) and hematoma volume (p < 0.0001). Additionally, isotype or separate types of hematoma on computed tomography (CT) (p < 0.0001) and laminar/separate types of hematoma types on MRI (p = 0.0008) were significant. Multivariate analysis revealed odds ratios of 2.50 (95% CI, 1.45-4.61; p = 0.0007) for male sex and 3.05 (95% CI, 1.95-4.87; p < 0.0001) for iso/separate hematoma types in CT. Conversely, among the patients who underwent MRI, multivariate analysis revealed odds ratios of 4.33 (95% CI, 1.20-27.92; p = 0.001) for male sex and 4.88 (95% CI, 1.90-14.18; p = 0.023) for laminar/separate hematoma types.

Conclusion: While distinguishing the nature of hematomas is challenging with brain CT examination, detailed laminar/trabecular differentiation using MRI images may predict postoperative recurrence.