Residual thromboembolic material in cerebral arteries after endovascular stroke therapy can be identified by dual-energy CT

Abstract

BACKGROUND AND PURPOSE: Dual-energy CT features the opportunity to differentiate among up to 3 different materials because the absorption of X-rays depends on the applied tube voltage and the atomic number of the material. For example, it is possible to distinguish between blood-brain barrier disruption and an intracerebral hemorrhage following treatment for a stroke. The aim of this study was to evaluate whether dual-energy CT is capable of distinguishing intra-arterial contrast agent from residually clotted vessels immediately after endovascular stroke therapy. MATERIALS AND METHODS: Sixteen patients (9 women, 7 men; mean age, 63.6±13.09 years) were examined. Measurements were made on the postinterventional dual-energy CT virtual noncontrast, iodine map, and "weighted" brain window (weighted dual-energy) series. Postinterventional conventional angiography was used as the criterion standard method. RESULTS: A residual clot was found in 10 patients. On the virtual noncontrast series, the Hounsfield attenuation of the clotted arteries was higher than that in the corresponding perfused contralateral arteries (53.72±9.42 HU versus 41.64±7.87 HU; P.05). The latter had higher absorption values on the weighted dual-energy series than on the virtual noncontrast series (49.37±7.44 HU versus 41.64±7.87 HU; P