Though not in a hospital setting, the “basilar ganglia” is a real error that was served up by Google’s healthcare AI model, Med-Gemini. A 2024 research paper introducing Med-Gemini included the hallucination in a section on head CT scans, and nobody at Google caught it, in either that paper or a blog post announcing it. When Bryan Moore, a board-certified neurologist and researcher with expertise in AI, flagged the mistake, he tells The Verge, the company quietly edited the blog post to fix the error with no public acknowledgement — and the paper remained unchanged. Google calls the incident a simple misspelling of “basal ganglia.” Some medical professionals say it’s a dangerous error and an example of the limitations of healthcare AI.

Med-Gemini is a collection of AI models that can summarize health data, create radiology reports, analyze electronic health records, and more. The pre-print research paper, meant to demonstrate its value to doctors, highlighted a series of abnormalities in scans that radiologists “missed” but AI caught. One of its examples was that Med-Gemini diagnosed an “old left basilar ganglia infarct.” But as established, there’s no such thing.

Fast-forward about a year, and Med-Gemini’s trusted tester program is no longer accepting new entrants — likely meaning that the program is being tested in real-life medical scenarios on a pilot basis. It’s still an early trial, but the stakes of AI errors are getting higher. Med-Gemini isn’t the only model making them. And it’s not clear how doctors should respond.

“What you’re talking about is super dangerous,” Maulin Shah, chief medical information officer at Providence, a healthcare system serving 51 hospitals and more than 1,000 clinics, tells The Verge. He added, “Two letters, but it’s a big deal.” —The Verge