Purpose: The aim was to assess the feasibility of dual-energy computed tomography (DE-CT) for detection of peri-interventional re-bleeding in patients with aneurysmal subarachnoid hemorrhage (re-SAH).
Methods: For in vitro-analyses DE-CT of partially clotted blood intermixed with fresh blood containing contrast agent was performed. In a clinical setting, 4 patients routinely underwent DE-CT after suspected peri-interventional re-SAH. DE-CT source data images, iodine maps and virtual non-contrast images (VNC) were analyzed and regions-of-interest (ROI) measurements of density values were performed.
Results: In vitro experiments demonstrated the feasibility of DE-CT to discriminate between blood with and without contrast agent. In all patients peri-interventional re-SAH was confirmed by detection of extravasated iodine within the subarachnoid spaces in post-interventional DE-CT. Dual-energy CT allowed the discrimination of old blood clots of the initial SAH and blood originating from peri-interventional re-SAH. After subtraction of the iodine-related high density signal, VNC images optimized the estimation of the true amount of subarachnoid blood.
Conclusion: Dual-energy CT allows the discrimination and subtraction of blood and iodine mixed within the subarachnoid spaces in patients with peri-interventional re-SAH. It helps to avoid overestimation of SAH after peri-interventional re-bleeding and therefore is a potentially valuable tool in the assessment of peri-interventional re-SAH.