The U.S. Food and Drug Administration (FDA) issued a letter to healthcare providers regarding the intended use of radiological computer-aided triage and notification (CADt) devices for intracranial large vessel occlusion (LVO).

LVO is an obstruction of 1 of the large arteries in the brain, and is a common cause of acute ischemic strokes. LVO CADt devices are software devices intended to aid in prioritization and triage of time-sensitive suspected findings of LVO based on the analysis of radiological exams of the brain. LVO CADt devices do not provide diagnostic information or remove any cases from the imaging physician’s reading queue. Information from real-world use suggests that providers may not be aware of the intended use of these devices. If LVO CADt devices are not used as intended, there is the potential for misdiagnosis, resulting in patient injury or death.

The FDA recommends that healthcare providers: 

  • Be aware that LVO CADt devices only flag radiological exams with suspected findings, and should never be used as a replacement for informed interpretation by an imaging physician.

  • Recognize that LVO CADt devices cannot rule out the presence of an LVO. If a radiological exam is not flagged by a LVO CADt device, an LVO may still be present.

  • Recognize that when the device is used as intended (as a prioritization and triage tool and not a diagnostic device), it can improve workflow by prioritizing suspected cases.

  • Recognize that the device does not remove any radiological exams from the queue for interpretation by an imaging physician. When used as intended, exams that are not flagged by the device are still interpreted by an imaging physician according to the standard of care.

  • Be aware of the design of LVO CADt devices. This includes an understanding of the vessels for which the device was designed and tested to detect LVO. LVO CADt devices may not be designed and tested to evaluate all intracranial vessels.

U.S. Food and Drug Administration (FDA). Intended Use of Imaging Software for Intracranial Large Vessel Occlusion – Letter to Health Care Providers. April 11, 2022. Available at: click here. Accessed April 13, 2022.