PT  - JOURNAL ARTICLE
AU  - A.E. Grams
AU  - M. Knoflach
AU  - R. Rehwald
AU  - J. Willeit
AU  - M. Sojer
AU  - E.R. Gizewski
AU  - B. Glodny
TI  - Residual Thromboembolic Material in Cerebral Arteries after Endovascular Stroke Therapy Can Be Identified by Dual-Energy CT
AID  - 10.3174/ajnr.A4350
DP  - 2015 Aug 01
TA  - American Journal of Neuroradiology
PG  - 1413--1418
VI  - 36
IP  - 8
4099  - http://www.ajnr.org/content/36/8/1413.short
4100  - http://www.ajnr.org/content/36/8/1413.full
SO  - Am. J. Neuroradiol.2015 Aug 01; 36
AB  - 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