TY - JOUR T1 - Residual Thromboembolic Material in Cerebral Arteries after Endovascular Stroke Therapy Can Be Identified by Dual-Energy CT JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 1413 LP - 1418 DO - 10.3174/ajnr.A4350 VL - 36 IS - 8 AU - A.E. Grams AU - M. Knoflach AU - R. Rehwald AU - J. Willeit AU - M. Sojer AU - E.R. Gizewski AU - B. Glodny Y1 - 2015/08/01 UR - http://www.ajnr.org/content/36/8/1413.abstract N2 - 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 < .05). The sensitivity for the detection of a residual clot was 90%; the specificity was 83.3%, and the accuracy was 87.5%. Interrater agreement was good (κ = 0.733).CONCLUSIONS: Dual-energy CT may be valuable in the detection of clot persistence or early re-thrombosis without the necessity of additional contrast administration. However, its relevance for the prediction of outcomes remains to be determined in further studies.CIconfidence intervalDECTdual-energy CTDEwweighted dual-energy seriesIMiodine map seriesVNCvirtual noncontrast series ER -