San Francisco startup seeks to solve radiologist shortage with new ‘AI-native’ imaging group
A San Francisco startup is seeking to solve the U.S. radiologist shortage by launching a new “AI-native” imaging group, claiming it can harness the technology to deliver faster interpretations.
Epsilon Health officially emerged from “stealth” mode on Thursday, announcing it has raised nearly $28 million from investors. Founded in 2024, Epsilon says it is different from other existing radiology AI companies that build models for a single disease or imaging modality.
Instead, the startup is taking a “fundamentally different approach” by becoming the “radiology practice itself.” Epsilon offers “purpose-built AI” that integrates directly into the work of board-certified radiologists. This, it claims, can dramatically accelerate interpretations while “preserving how providers already deliver care.”
“Growing up around my dadʼs imaging practice, I saw firsthand the profound impact of misdiagnosis. When a diagnosis is missed or delayed, it can quickly change the course of someone's life,” Rustin Rassoli, founder and CEO of Epsilon Health, who studied mathematics and computer science at the University of Texas at Austin, said in a statement Sept. 10. “Americaʼs growing shortage of radiologists is putting real lives at even greater risk—the system is collapsing, and patients are bearing the brunt of it.
“Thatʼs why weʼre building a radically new approach to radiology at Epsilon, where radiologists and technologists work as one team to solve this growing bottleneck and create a world where no diagnosis is missed, delayed or wrong,” added Rassoli.
New York-based venture capital firm AlleyCorp led the Series A financing round. Other participating investment firms included Uncork Capital, Renegade Partners, and SemperVirens. American businessman and entrepreneur Jack Altman—brother of OpenAI CEO and founder Sam Altman—also pitched in while serving as managing partner at Alt Capital.
Epsilon noted that an estimated 75% of all medical decisions rely on radiology to diagnose and treat disease. However, the U.S. continues to face a “critical shortage” of radiologists amid surging demand, with bottlenecks purportedly leading to delayed treatments. Epsilon claims its proprietary AI technology can help to expand radiologist capacity, allowing docs to deliver “faster, more consistent diagnoses at scale.”
To date, the company has now served over 250,000 patients, processing more than 2,500 imaging studies per day. It is on track to review about 1% of all daily U.S. X-rays in 2026 and already handles half of the scan volume or one of the nation’s largest outpatient imaging providers. Its leadership team includes Head of Machine Learning Arjun Karpur, MS, who previously led research at Google DeepMind, and radiologist Roi Bittane, MD, the former chief medical officer of Envision Healthcare, who will serve as CMO for Epsilon.
Rassoli and colleagues said they plan to use the new funding to accelerate market expansion and support the practice through hiring, clinical partnerships and new infrastructure spending. Investments will seek to advance Epsilon’s mission to “ensure every patient has access to timely, high-quality diagnostic expertise, powered by AI and physicians working together.”
“Epsilon has built an entirely new kind of radiology practice, which I think makes a great blueprint for how healthcare will be done in the future,ˮ Jack Altman said in the announcement. “In less than 10 months, theyʼve gone from nothing to processing thousands of studies a day for some of the largest imaging providers in the country. I couldn't be more excited about what theyʼre doing.ˮ
Marty Stempniak has covered healthcare since 2012, with his byline appearing in the American Hospital Association's member magazine, Modern Healthcare and McKnight's. Prior to that, he wrote about village government and local business for his hometown newspaper in Oak Park, Illinois. He won a Peter Lisagor and Gold EXCEL awards in 2017 for his coverage of the opioid epidemic.