Added value of brain perfusion ultrasound to prehospital stroke scales-a secondary analysis of the SONAS trial
5 affiliations
- 1Department of Neurology, University of Regensburg, Medbo Bezirksklinikum, TEMPiS Telestroke Center, and University Clinic Regensburg
- 2Department of Anaesthesiology, St. Josef Hospital Regensburg
- 3Center for Human Genetics
- 4Center for Neuroradiology, University Clinic Regensburg
- 5Department of Neurology, University of California, Los Angeles Medical Center
Abstract
Introduction: Accurate prehospital identification of acute ischemic stroke due to large vessel occlusion (LVO) is critical to guide selection of an optimal target hospital for either intravenous thrombolysis (IVT) alone and/or mechanical thrombectomy (MT). The novel portable non-imaging brain perfusion ultrasound (BPU) device SONAS(TM) indicated similar sensitivity and specificity as prehospital stroke scales. In this study, we reanalyzed data from the original 20 patient cohort to evaluate whether combining BPU with prehospital stroke scales (ph-SS) can further improve LVO detection.
Methods: Clinical data and NIHSS scores of all patients suffering from acute ischemic stroke with and without proven LVO in the SONAS trial were collected and applied to 16 different phSS. As an exploratory analysis we also applied a prehospital score for intracerebral hemorrhage (ph-ICH) to this cohort. The positive and negative predictive values as well as sensitivity and specificity were analyzed retrospectively for both methods.
Results: The best performing phSS, CG-FAST, and RACE, showed comparable performances to BPU, but still misdiagnosed patients. However, in our specific cohort, the combination of both methods allowed for a reliable classification into three groups: (A) “highly probably LVO”, (B) “highly probable non-LVO” and (C) “not assessable” (including all patients misdiagnosed by one method alone). The addition of BPU resulted in shifts towards higher sensitivity and NPV. When using the ph-ICH score three patients were classified as ICH (false positive), and all of them showed severe perfusion deficits in BPU indicating LVO.
Conclusion: The combination of BPU with phSS may hold the potential to enhance prehospital triage of acute stroke patients selecting patients to (A) endovascular-capable centers, (B) the nearest stroke unit for, i.e., IVT or (C) either depending on other clinical factors and local circumstances. However, validation is critical in stroke-call patients in the prehospital setting including application by paramedics with/without emergency physicians or telemedical support, and compared to other prehospital point-of-care diagnostics both in respect to sensitivity/specificity, timeline and, ultimately, costs. In the future, the addition of serum biomarkers for ICH may open new opportunities for early ICH treatment or even enable prehospital IVT, and/or streamline direct to angio-suite approaches in confirmed LVO.
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BibTeX
@article{birner2026added,
title = {{Added value of brain perfusion ultrasound to prehospital stroke scales-a secondary analysis of the SONAS trial}},
author = {Nicole Birner and Sibylle Wilfling and Mustafa Kilic and Christina Wendl and Amir M. Molaie and Ralf A. Linker and David S. Liebeskind and Felix Schlachetzki},
journal = {Frontiers in Neurology},
year = {2026},
month = oct,
doi = {10.3389/fneur.2026.1924664},
url = {https://www.frontiersin.org/articles/10.3389/fneur.2026.1924664/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Added value of brain perfusion ultrasound to prehospital stroke scales-a secondary analysis of the SONAS trial
AU - Nicole Birner
AU - Sibylle Wilfling
AU - Mustafa Kilic
AU - Christina Wendl
AU - Amir M. Molaie
AU - Ralf A. Linker
AU - David S. Liebeskind
AU - Felix Schlachetzki
PY - 2026
DA - 2026/10/23
JO - Frontiers in Neurology
DO - 10.3389/fneur.2026.1924664
UR - https://www.frontiersin.org/articles/10.3389/fneur.2026.1924664/full
AB - Introduction: Accurate prehospital identification of acute ischemic stroke due to large vessel occlusion (LVO) is critical to guide selection of an optimal target hospital for either intravenous thrombolysis (IVT) alone and/or mechanical thrombectomy (MT). The novel portable non-imaging brain perfusion ultrasound (BPU) device SONAS(TM) indicated similar sensitivity and specificity as prehospital stroke scales. In this study, we reanalyzed data from the original 20 patient cohort to evaluate whether combining BPU with prehospital stroke scales (ph-SS) can further improve LVO detection. Methods: Clinical data and NIHSS scores of all patients suffering from acute ischemic stroke with and without proven LVO in the SONAS trial were collected and applied to 16 different phSS. As an exploratory analysis we also applied a prehospital score for intracerebral hemorrhage (ph-ICH) to this cohort. The positive and negative predictive values as well as sensitivity and specificity were analyzed retrospectively for both methods. Results: The best performing phSS, CG-FAST, and RACE, showed comparable performances to BPU, but still misdiagnosed patients. However, in our specific cohort, the combination of both methods allowed for a reliable classification into three groups: (A) “highly probably LVO”, (B) “highly probable non-LVO” and (C) “not assessable” (including all patients misdiagnosed by one method alone). The addition of BPU resulted in shifts towards higher sensitivity and NPV. When using the ph-ICH score three patients were classified as ICH (false positive), and all of them showed severe perfusion deficits in BPU indicating LVO. Conclusion: The combination of BPU with phSS may hold the potential to enhance prehospital triage of acute stroke patients selecting patients to (A) endovascular-capable centers, (B) the nearest stroke unit for, i.e., IVT or (C) either depending on other clinical factors and local circumstances. However, validation is critical in stroke-call patients in the prehospital setting including application by paramedics with/without emergency physicians or telemedical support, and compared to other prehospital point-of-care diagnostics both in respect to sensitivity/specificity, timeline and, ultimately, costs. In the future, the addition of serum biomarkers for ICH may open new opportunities for early ICH treatment or even enable prehospital IVT, and/or streamline direct to angio-suite approaches in confirmed LVO.
SN - 1664-2295
ER -