An artificial intelligence tool that reads chest X-rays without oversight from a radiologist got regulatory clearance in the European Union last week — a first for a fully autonomous medical imaging AI, the company, called Oxipit, said in a statement. It’s a big milestone for AI and likely to be contentious, as radiologists have spent the last few years pushing back on efforts to fully automate parts of their job.

The tool, called ChestLink, scans chest X-rays and automatically sends patient reports on those that it sees as totally healthy, with no abnormalities. Any images that the tool flags as having a potential problem are sent to a radiologist for review. Most X-rays in primary care don’t have any problems, so automating the process for those scans could cut down on radiologists’ workloads, the Oxipit said in informational materials.

The tech now has a CE mark certification in the EU, which signals that a device meets safety standards. The certification is similar to Food and Drug Administration (FDA) clearance in the United States, but they have slightly different metrics: a CE mark is less difficult to obtain, is quicker, and doesn’t require as much evaluation as an FDA clearance. The FDA looks to see if a device is safe and effective and tends to ask for more information from device makers.

Oxipit spokesperson Mantas Miksys told The Verge that the company plans to file with the FDA as well.

The FDA has cleared autonomous AI devices before, starting with a tool that can detect diabetes-related eye problems in 2018 (the same tool received a CE mark in 2013). But autonomous radiology devices are more controversial. Professional organizations have spoken out against the idea: the American College of Radiology and the Radiological Society of North America published a joint letter in 2020 after an FDA workshop on artificial intelligence in medical imaging, saying that autonomous AI wasn’t ready for clinical use. So far, they said, AI programs were too inconsistent and often didn’t perform as well on groups of patients outside of the original environments they were built in.

Oxipit said in a statement that ChestLink made zero “clinically relevant” errors during pilot programs at multiple locations. When it is introduced into a new setting, the company said there should first be an audit of existing imaging programs. Then, the tool should be used under supervision for a period of time before it starts working autonomously.

The company said in a statement that it expects the first healthcare organizations to be using the autonomous tool by 2023.