On April 11, 2022, the U.S. Food and Drug Administration (FDA) issued an open letter to health care providers reminding them about the intended uses and limitations of radiological computer-aided triage and notification (CADt) devices. The CADt devices use artificial intelligence (AI) to prioritize radiology images and speed up reviews in time-sensitive conditions such as acute ischemic strokes caused by intracranial large vessel occlusion (LVO), which is obstruction of one of the large arteries in the brain.

The letter from FDA recommends that health care providers be aware that LVO CADt devices only flag radiological exams with suspected findings and should never be used as a replacement for an interpretation performed by a credentialed physician, e.g., a radiologist. FDA cautions that LVO CADt devices should not be used to rule out the presence of an LVO. If a radiological exam is not flagged by an LVO CADt device, the letter warns that an LVO could still be present. Health providers should use the device only as a prioritization and triage tool and not as a diagnostic device. It is intended to be used only to improve workflow by prioritizing suspected cases. 

FDA's letter stated that the use of the LVO CADt device should never result in radiological exams being removed from the queue of interpreting physicians. And finally, FDA cautions that LVO CADt devices may not be designed and tested to evaluate all intracranial vessels.

FDA's letter notes that the agency is engaged in continuing efforts to evaluate the real-world performance of artificial intelligence/machine learning imaging devices, including CADt devices. The FDA advised that it will keep health care providers and the public informed of new or additional information as it becomes available.