Detecting Large Vessel Occlusion at Multiphase CT Angiography by Using a Deep Convolutional Neural Network.

Background Large vessel occlusion (LVO) stroke is one of the most time-sensitive diagnoses in medicine and requires emergent endovascular therapy to reduce morbidity and mortality. Leveraging recent advances in deep learning may facilitate rapid detection and reduce time to treatment. Purpose To develop a convolutional neural network to detect LVOs at multiphase CT angiography. Materials and Methods This multicenter retrospective study evaluated 540 adults with CT angiography examinations for suspected acute ischemic stroke from February 2017 to June 2018. Examinations positive for LVO (n = 270) were confirmed by catheter angiography and LVO-negative examinations (n = 270) were confirmed through review of clinical and radiology reports. Preprocessing of the CT angiography examinations included vasculature segmentation and the creation of maximum intensity projection images to emphasize the contrast agent-enhanced vasculature. Seven experiments were performed by using combinations of the three phases (arterial, phase 1; peak venous, phase 2; and late venous, phase 3) of the CT angiography. Model performance was evaluated on the held-out test set. Metrics included area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Results The test set included 62 patients (mean age, 69.5 years; 48% women). Single-phase CT angiography achieved an AUC of 0.74 (95% confidence interval [CI]: 0.63, 0.85) with sensitivity of 77% (24 of 31; 95% CI: 59%, 89%) and specificity of 71% (22 of 31; 95% CI: 53%, 84%). Phases 1, 2, and 3 together achieved an AUC of 0.89 (95% CI: 0.81, 0.96), sensitivity of 100% (31 of 31; 95% CI: 99%, 100%), and specificity of 77% (24 of 31; 95% CI: 59%, 89%), a statistically significant improvement relative to single-phase CT angiography (P = .01). Likewise, phases 1 and 3 and phases 2 and 3 also demonstrated improved fit relative to single phase (P = .03). Conclusion This deep learning model was able to detect the presence of large vessel occlusion and its diagnostic performance was enhanced by using delayed phases at multiphase CT angiography examinations. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Ospel and Goyal in this issue.

Community Health Workers' Role in Supporting Pediatric Asthma Management: A Review.

Objective: Community Health Workers (CHWs) have been effective in improving health outcomes in vulnerable communities by providing health education and management services. We review CHW-led asthma education and management interventions for children and their families. Next, we describe the selection and training of CHWs in pediatric asthma management in the Rhode Island Integrated Response Asthma Care Implementation Program (RI-AIR). Methods: We queried the MEDLine, Cochrane, PubMed, and EMBASE databases with keywords ("community health worker", "asthma", "health worker", "lay worker", "pediatric", "child", and "childhood") from inception until September 2019. Criteria for study inclusion included: published in English, conducted in the United States, approved with an ethics notification, published in peer-reviewed journal, and involved CHWs as the interventionists. The initial search identified 216 manuscripts. Fifteen studies met criteria for inclusion. Results: CHWs provide asthma management and education services, including home environmental trigger assessments, strategies to reduce environmental trigger exposure, resource linkage, and community referrals. We describe RI-AIR, and its CHW-led asthma education and management interventions. Conclusions: CHWs are effective and vital supports for positive asthma outcomes. More research is needed to guide models of intervention using CHWs, specifically addressing integration in interdisciplinary teams, training, and reimbursement for CHW services. Implications for Impact Statement: CHWs are effective in helping children with asthma and their families learn to manage asthma. It is important to develop programs that prepare CHWs to work with other medical professionals and health care models to pay for their services.