@article {644688,
	title = {Big Data Approaches to Phenotyping Acute Ischemic Stroke Using Automated Lesion Segmentation of Multi-Center Magnetic Resonance Imaging Data},
	journal = {Stroke},
	volume = {50},
	number = {7},
	year = {2019},
	month = {2019 Jul},
	pages = {1734-1741},
	abstract = {Background and Purpose- We evaluated deep learning algorithms{\textquoteright} segmentation of acute ischemic lesions on heterogeneous multi-center clinical diffusion-weighted magnetic resonance imaging (MRI) data sets and explored the potential role of this tool for phenotyping acute ischemic stroke. Methods- Ischemic stroke data sets from the MRI-GENIE (MRI-Genetics Interface Exploration) repository consisting of 12 international genetic research centers were retrospectively analyzed using an automated deep learning segmentation algorithm consisting of an ensemble of 3-dimensional convolutional neural networks. Three ensembles were trained using data from the following: (1) 267 patients from an independent single-center cohort, (2) 267 patients from MRI-GENIE, and (3) mixture of (1) and (2). The algorithms{\textquoteright} performances were compared against manual outlines from a separate 383 patient subset from MRI-GENIE. Univariable and multivariable logistic regression with respect to demographics, stroke subtypes, and vascular risk factors were performed to identify phenotypes associated with large acute diffusion-weighted MRI volumes and greater stroke severity in 2770 MRI-GENIE patients. Stroke topography was investigated. Results- The ensemble consisting of a mixture of MRI-GENIE and single-center convolutional neural networks performed best. Subset analysis comparing automated and manual lesion volumes in 383 patients found excellent correlation (ρ=0.92; P,
	issn = {1524-4628},
	doi = {10.1161/STROKEAHA.119.025373},
	author = {Wu, Ona and Winzeck, Stefan and Giese, Anne-Katrin and Hancock, Brandon L and Etherton, Mark R and Bouts, Mark J R J and Donahue, Kathleen and Schirmer, Markus D and Irie, Robert E and Mocking, Steven J T and McIntosh, Elissa C and Bezerra, Raquel and Konstantinos Kamnitsas and Frid, Petrea and Wasselius, Johan and Cole, John W and Xu, Huichun and Holmegaard, Lukas and Jim{\'e}nez-Conde, Jordi and Lemmens, Robin and Lorentzen, Eric and McArdle, Patrick F and Meschia, James F and Roquer, Jaume and Rundek, Tatjana and Sacco, Ralph L and Schmidt, Reinhold and Sharma, Pankaj and Slowik, Agnieszka and Stanne, Tara M and Thijs, Vincent and Vagal, Achala and Woo, Daniel and Bevan, Stephen and Kittner, Steven J and Mitchell, Braxton D and Rosand, Jonathan and Worrall, Bradford B and Jern, Christina and Lindgren, Arne G and Maguire, Jane and Rost, Natalia S}
}