{"id":"AIBD-0622","title":"FDA De Novo review of Viz.ai ContaCT: in a test on past scans, stroke alerts came about 51 minutes before usual care","summary":"In a retrospective test that FDA reviewed, Viz.ai ContaCT sent its stroke alert in 7.32 minutes on average, against 58.72 minutes for usual-care notification of the specialist.","date_observed":"2018-02-13","date_basis":"source publication","date_precision":"day","benefit_status":"intended","source_collection":null,"source_entry":null,"account":"Viz.ai of San Francisco submitted its ContaCT software to FDA as a tool that reads CT angiograms of the brain and alerts a neurovascular specialist when it suspects a large vessel occlusion. In a retrospective standalone test on 300 CT angiograms from two US clinical sites, the software had a sensitivity of 87.8% and a specificity of 89.6%. For 44 cases with a true occlusion and a recorded usual-care time, the study compared the time from scan to specialist notification. The mean was 58.72 minutes in usual care and 7.32 minutes for the software, a mean difference of 51.40 minutes. FDA granted the De Novo request on 13 February 2018. The reviewers note that the time comparison could only use the subset of cases with usual-care times and may hold some bias. The test used past scans, so the alerts did not change care, and the review did not measure patient outcomes.","category":"general benefit","unexpected":false,"purpose":"ContaCT was built to alert a stroke specialist to a suspected large vessel occlusion in parallel with the usual radiology read. Faster alerts are that purpose.","system":"ContaCT","model_version":null,"developer":"Viz.ai, Inc.","deployer":"Viz.ai (standalone performance test on archived CT angiograms)","location":"Two clinical sites, United States","domain":"Healthcare","segment":null,"benefit_type":"Reduced Task Time","taxonomy_note":null,"registry_ids":{},"ratings":[{"group":"organizational","depth":null,"reason":"The 51-minute difference comes from a retrospective test on past scans in which no alert reached a specialist, so no realized gain for the sites is reported."}],"ai_role":{"status":"assessed","statement":"FDA reviewers compared the alert time of the software with the recorded usual-care alert time on the same 44 cases, a paired comparison with and without the software."},"evidence":[{"kind":"regulatory document","citation":"U.S. Food and Drug Administration, Center for Devices and Radiological Health. De Novo classification request for ContaCT (DEN170073): decision summary. 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