Acute arterial occlusions like in cerebral stroke are in most cases caused by vascular thrombi second to atherothrombosis or thromboembolism [1]. Depending on the circumstances during thrombogenesis, these thrombi can hereby be of different entities that also offer varying proportions of cellular and tissue components such as red blood cells (RBC) or fibrin [1, 2]. The proportions of these components have a decisive influence on the thrombi‘s biomechanical properties, as, e.g., red, RBC-rich thrombi are considered soft while white, fibrin-rich thrombi tend to be more rigid [1 - 3]. As a consequence of these biomechanical differences, the effectiveness of interventional or pharmaceutical therapies in the treatment of acute stroke varies depending on the underlying thrombus type [4, 5]. Accordingly, the thrombus type may affect the patient’s outcome, and pre-interventional diagnostic thrombus characterisation by imaging techniques could therefore be a promising approach to improve therapeutic efficiency [6, 7]. Therapeutic procedures could then be precisely tailored to the specific thrombus. In this regard, spectral computed tomography is an innovative imaging technique that enables tissue characterisation beyond conventional X-ray density and could therefore provide relevant information about the composition of the thrombus [6 - 8]. The present study analysed the spectral properties of thrombi of different composition using spectral detector CT (SDCT).