January-February 2019

Residual Thromboembolic Material in Cerebral Arteries after Endovascular Stroke Therapy Can Be Identified by Dual-Energy CT

Astrid E. Grams

CT is a quickly accessible imaging modality in most centers; however, one of its disadvantages is inferior tissue discrimination compared with MRI. Dual-energy CT can partly compensate for this limitation. Besides the possibility to reduce radiation dose or contrast agent administration with the same resulting imaging quality, the method features the opportunity to reduce beam-hardening artifacts and to improve tissue discrimination.

Our group has published and is currently performing studies on the 2 latter topics. One of the research fields is a large cohort of patients who have received a thrombectomy due to cerebral stroke and a dual-energy CT immediately after the intervention. Our group is focused on improving the visualization of relevant tissues (ie, blood vessels and brain tissue), especially in patients with acute stroke, for whom a fast imaging modality in order to make fast clinical decisions is crucial. The study performed to visualize residual clots after thrombectomy was the first publication in this series.

In our center, dual-energy CT is routinely applied in patients after thrombectomy, not only to visualize residual clots, but also to detect hemorrhage and infarction demarcation. Our group found that from the amount of contrast extravasation it can be predicted if in the near future a cerebral hemorrhage may occur. In addition, we found that the future size of the infarction can be predicted with the dual-energy technique.

We received mostly positive feedback after the publication of this study and the other dual-energy CT studies we have published so far. During international scientific conferences there have been interesting questions from colleagues who are planning to establish this method in their centers.

We are currently working on a big data analysis of our large, retrospective cohort of patients who received dual-energy CT early after a thrombectomy in order to work out further predictive features concerning infarction or clinical development. In addition, we are working on the optimization of imaging in patients with intracerebral or dental implants with the help of dual-energy CT.

In November 2018, I presented our data on infarction visualization with dual-energy CT at the Austrian Society of Neuroradiology’s annual meeting in Vienna, Austria. In addition, I will give a teaching lecture on the application of dual-energy CT during next year‘s European Stroke Organization Conference in Milan, Italy.

Read this article at AJNR.org