Utilizing dual energy CT to distinguish blood from contrast leakage following middle meningeal artery embolization for chronic subdural hematomas

Background Recently, middle meningeal artery (MMA) embolization has emerged as a potential alternative treatment option for chronic subdural hematomas (SDH). Imaging following MMA embolization often shows high density material in the subdural space, usually representing contrast leakage through the dura or, less commonly, hemorrhage. These cannot be reliably differentiated on conventional CT. Dual energy CT (DECT) provides the ability to differentiate materials that otherwise appear similar on conventional CT such as blood and iodine. Methods A retrospective review was conducted to evaluate patients who underwent MMA embolization for SDH between May 2019 and April 2020. Post-procedural head CT performed on an IQon Elite Spectral CT detector-based DECT scanner enabled two-material decomposition to separate iodine from blood. The dual energy reconstructions used included the virtual non-contrast and iodine no-water images. Results Four representative illustrative cases were selected to highlight the ability of DECT to characterize new hyperdensity on head CT following MMA embolization as blood, contrast or a combination. Conclusions DECT allows objective differentiation of contrast leakage from blood following MMA embolization. This technology can obviate the need for additional follow-up scanning and prolonged patient observation, which in turn can result in reduced costs and radiation exposure to patients.