Abstract
Objectives
The Alberta Stroke Program Early CT Score (ASPECTS) is a semi-quantitative method to evaluate the severity of early ischemic change on non-contrast computed tomography (NCCT) in patients with acute ischemic stroke (AIS). In this work, we propose an automated ASPECTS method based on large cohort of data and machine learning.
Methods
For this study, we collected 3626 NCCT cases from multiple centers and annotated directly on this dataset by neurologists. Based on image analysis and machine learning methods, we constructed a two-stage machine learning model. The validity and reliability of this automated ASPECTS method were tested on an independent external validation set of 300 cases. Statistical analyses on the total ASPECTS, dichotomized ASPECTS, and region-level ASPECTS were presented.
Results
On an independent external validation set of 300 cases, for the total ASPECTS results, the intraclass correlation coefficient between automated ASPECTS and expert-rated was 0.842. The agreement between ASPECTS threshold of ≥ 6 versus < 6 using a dichotomized method was moderate (κ = 0.438, 0.391–0.477), and the detection rate (sensitivity) was 86.5% for patients with ASPECTS threshold of ≥ 6. Compared with the results of previous studies, our method achieved a slight lead in sensitivity (67.8%) and AUC (0.845), with comparable accuracy (78.9%) and specificity (81.2%).
Conclusion
The proposed automated ASPECTS method driven by a large cohort of NCCT images performed equally well compared with expert-rated ASPECTS. This work further demonstrates the validity and reliability of automated ASPECTS evaluation method.
Clinical relevance statement
The automated ASPECTS method proposed by this study may help AIS patients to receive rapid intervention, but should not be used as a stand-alone diagnostic basis.
Key Points
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NCCT-based manual ASPECTS scores were poorly consistent.
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Machine learning can automate the ASPECTS scoring process.
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Machine learning model design based on large cohort data can effectively improve the consistency of ASPECTS scores.
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Abbreviations
- AIS:
-
Acute ischemic stroke
- ASPECTS:
-
Alberta Stroke Program Early CT Score
- C:
-
Caudate head
- GLCM:
-
Gray-level co-occurrence matrix
- GLDM:
-
Gray-level dependence matrix
- GLRLM:
-
Gray-level run length matrix
- GLSZM:
-
Gray-level size zone matrix
- I:
-
Insula
- IC:
-
Internal capsule
- ICC:
-
Intraclass correlation coefficient
- IQR:
-
Interquartile range
- L:
-
Lentiform nucleus
- LBP:
-
Local binary pattern
- LVO:
-
Large vessel occlusion
- M1:
-
Frontal operculum
- M2:
-
Temporal lobe
- M3:
-
Posterior temporal lobe
- M4:
-
Anterior MCA
- M5:
-
Lateral MCA
- M6:
-
Posterior MCA
- MCA:
-
Middle cerebral artery
- NCCT:
-
Non-contrast computed tomography
- NGTDM:
-
Neighboring gray-tone difference matrix
- SOTA:
-
State-of-the-art
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Acknowledgements
We would like to acknowledge the contribution of neurologists Dr. Shu Wan and Dr. Sheng Guan for their valuable assistance with the clinical interpretation. We also would like to thank the following colleagues: Wei Lu, Yu Fu, Ming Wang, Kaizheng Liu, Sijing Chen, Wubiao Chen, Yang Wang, Jun Wu, Xiaochang Leng, Jens Fiehler, Adnan H. Siddiqui, and Jianping Xiang. Special thanks to ArteryFlow Technology Co., Ltd., for the technical support of this research.
Funding
This work was supported by the Key Research and Development Project of Zhejiang Provincial Department of Science and Technology (Grant No. 2021C03105), Medical Health Science and Technology Project of Zhejiang Provincial Health Commission (Grant No. WKJ-ZJ-2014), and Hangzhou Leading Innovation and Entrepreneurship Team Project (TD2022007).
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The scientific guarantor of this publication is Jianping Xiang.
Conflict of interest
The authors of this manuscript declare relationships with the following companies: ArteryFlow Technology Co., Ltd. The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
Statistics and biometry
No complex statistical methods were necessary for this paper. Some simple descriptive statistics and graphs were used in the study.
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Written informed consent was waived by the Institutional Review Board.
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Institutional Review Board approval was obtained.
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All of the study subjects or cohorts have not been previously reported.
Methodology
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retrospective
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multicenter study
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Wan, S., Lu, W., Fu, Y. et al. Automated ASPECTS calculation may equal the performance of experienced clinicians: a machine learning study based on a large cohort. Eur Radiol 34, 1624–1634 (2024). https://doi.org/10.1007/s00330-023-10053-z
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DOI: https://doi.org/10.1007/s00330-023-10053-z