CT and MR imaging of chronic subdural haematomas: a comparative study

Questions under study/principles: This study was designed to compare CT and MR appearances of chronic subdural haematomas as well as CT- and MR-guided measurements of haematoma thicknesses. Methods: CT and MR images of 48 chronic subdural haematomas of 34 patients were reviewed retrospectively. The thickness measurements and imaging characteristics of haematomas were compared. Results: Levelling was observed in 25% of haematomas, and most of them (60%) had intra-haematomal membranes. All membranes could be delineated by MR imaging, whereas only 27% were defined by CT. Mixed density (52%) and T1 hyperintensity (59%) were commonly observed in membraned haematomas, but the difference was not statistically significant. Haematomas were measured significantly thicker on MR images. All patients had been treated with burr-hole craniotomy and irrigation. Conclusions: MR imaging is more sensitive than CT in determining the size and internal structures of chronic subdural haematomas.