Study Population

Informed consent was obtained by the patients or legal representatives according to local law and regulations. Institutional review board approval was obtained before the commencement of this study and this study was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.

A total of 16 patients were included. Inclusion criteria were a National Institutes of Health Stroke Scale (NIHSS) > 3, age > 18 years, AIS symptoms due to suspected LVO and transfer from non-endovascular capable centers (nECC) to receive EVT (drip and ship model). To compare time metrics without any bias due to performed general anesthesia (GA), only patients with externally performed GA were included. Moreover, to avoid exposing patients to unnecessary radiation, only patients were included in which an externally performed imaging was not delivered, so new imaging before EVT was required for treatment decision (hemorrhage exclusion, LVO detection, situation of brain hemodynamics).

Our patient collective consisted of two parts. First, we screened prospectively for patients eligible for multimodal FD-CT. Out of 163 AIS patients that received EVT due to LVO between January 2020 and October 2020 (10 months), eight patients met the inclusion criteria and were transferred to the angiosuite, where multimodal FD-CT imaging was performed before EVT due to clinical indication.

Second, we screened our database for AIS patients that received EVT in our department and received multimodal CT imaging before transfer to the angiosuite. Between August 2017 and January 2019 (15 months), 261 patients with LVO received EVT in our department. During that period eight patients, that were screened retrospectively, met the inclusion criteria.

For all patients major workflow times were recorded: Time of AIS onset; Time of arrival in the ER of our center; Time of cerebral imaging; Time of groin puncture; Time of last DSA series. From the recorded data, several time intervals were calculated: Symptom onset to initial imaging (onset-to-image); ER arrival to initial imaging (door-to-image); ER arrival to groin puncture (door-to-groin-puncture); initial imaging to groin puncture (image-to-groin-puncture); initial imaging to reperfusion (image-to-reperfusion); groin puncture to reperfusion (groin-puncture-to-reperfusion). “Groin puncture” was defined as the moment when the interventionalist cannulates the inguinal artery to gain access to the patient's arterial system, thereby beginning the EVT procedure. “Reperfusion” was defined as the end of EVT, irrespective of the achieved TICI score. Workflow is pictured in Fig. 1.

The Workflow that was used. Patients presented externally at an nECC with suspected LVO. GA took place at the nECC or before. Afterwards, the patients were presented at our ECC. In our cohort external performed imaging was not presented to the ECC neuroradiology department. When the interventional neuroradiologist demanded additional imaging, multimodal CT imaging was performed before EVT. After establishing our new FD-CT protocol multimodal imaging was performed in the angiosuite using FD-CT