The Potential of Diffusion-Weighted Magnetic Resonance Imaging for Predicting the Outcomes of Chronic Subdural Hematomas.

Objective: Diffusion-weighted magnetic resonance imaging (DW-MRI) has proven useful in the study of the natural history of ischemic stroke. However, the potential of DW-MRI for the evaluation of chronic subdural hematoma (CSDH) has not been established. In this study, we investigated DW-MRI findings of CSDH and evaluated the impact of the image findings on postoperative outcomes of CSDH.

Methods: We studied 131 CSDH patients who had undergone single burr hole drainage surgery. The images of the subdural hematomas on preoperative DW-MRI and computed tomography (CT) were divided into three groups based on their signal intensity and density: 1) homogeneous (iso or low) density on CT and homogeneous low signal intensity on DW-MRI; 2) homogeneous (iso or low) density on CT and mixed signal intensity on DW-MRI; and 3) heterogeneous density on CT and mixed signal intensity on DW-MRI. On the basis of postoperative CT, we also divided the patients into 3 groups of surgical outcomes according to residual hematoma and mass effect.

Results: Analysis showed statistically significant differences in surgical (A to B: p <0.001, A to C: p <0.001, B to C: p =0.129) and functional (A to B: p =0.039, A to C: p <0.001, B to C: p =0.108) outcomes and treatment failure rates (A to B: p =0.037, A to C: p =0.03, B to C: p =1) between the study groups. In particular, group B and group C showed worse outcomes and higher treatment failure rates than group A.

Conclusion: CSDH with homogeneous density on CT was characterized by signal intensity on DW-MRI. In CSDH patients, performing DW-MRI as well as CT helps to predict postoperative treatment failure or complications.