California-based Subtle Medical has raised $33 million in a Series C growth round and named industry veteran Ohad Arazi chief executive, as it tries to turn its AI-powered medical imaging software into the standard layer health systems run scans on.
Morgan Stanley leads, Samsung returns
The round was led by Morgan Stanley Expansion Capital, with participation from Shinhan Venture Investment and existing investors Fusion Fund, BRV and Samsung Ventures. The fresh capital brings Subtle's lifetime funding to $86 million. The Menlo Park company plans to use the proceeds to accelerate global commercialisation and deepen its product portfolio.
SubtleHD and SubtlePET: speed by AI, not by hardware
Subtle's lead products are SubtlePET and SubtleHD, software-as-a-medical-device tools that use deep learning to enhance and reconstruct medical images. As with peers in deep-learning MRI reconstruction, the approach lets radiology departments cut MRI scan times by up to 80% on installed hardware — meaningful throughput gains without buying new magnets. SubtlePET was first cleared by the U.S. Food and Drug Administration in 2018; SubtleHD followed in February 2025.
A broader Subtle-ELITE suite
Around those flagships, Subtle has built the Subtle-ELITE suite, which now also includes SubtleALIGN — an automatic brain-MR alignment tool — and SubtleSYNTH, which generates additional MR imaging contrasts from existing sequences. The aim is to position Subtle as a vendor-neutral platform spanning MR, PET and CT workflows.
New CEO brings imaging-plus-enterprise lineage
Arazi previously held CEO and senior roles at Change Healthcare, Zebra Medical Vision and Clarius Mobile Health. "What drew me to Subtle is that this isn't a point solution — it's becoming the AI layer where health systems run their imaging," he said. Co-founder Enhao Gong moves to chief science officer, while Greg Zaharchuk remains on the team.
Imaging is the AI in healthcare hotspot
The raise lands as healthcare AI spending balloons. GlobalData puts the combined AI market across healthcare at $11.9 billion in 2024, projected to hit $57.4 billion by 2029, with medical imaging consistently flagged as the fastest-to-scale clinical use case alongside AI-designed cancer therapies.
Reporting based on coverage from Medical Device Network (Ross Law, 2 June 2026), Fierce Healthcare and PR Newswire.