Rad AI vs Subtle Medical (2026)
Two radiology products that never touch each other's work. Rad AI writes the report impression from the radiologist's own dictated findings, learning their individual language from prior reports, with the clearest structural oversight in this index because the workflow enforces it. Subtle changes the image itself, with deep learning reconstruction letting a department scan faster or at lower dose on existing scanners, backed by eleven clearances and more than twenty five publications. One returns radiologist time, the other returns scanner time, and which matters depends entirely on where your queue actually forms. Note the asymmetry in failure: a degraded report is read and corrected, while a degraded reconstruction produces a cleaner image that lost something nobody will notice.
- It generates the report impression from the radiologist's own dictated findings and learns that radiologist's language from their prior reports.
- The oversight model is structurally the clearest in this index because the workflow enforces it, with the model drafting and the radiologist signing.
- It publishes specific falsifiable operational figures with named baselines, including follow up completion.
- It changes the image rather than the report, with deep learning reconstruction and denoising letting a department scan faster or at lower dose.
- Eleven clearances across two modalities and more than twenty five peer reviewed publications, with a published standards based integration specification.
- The benefit lands on the scanner rather than the reading list, which is a different constraint and often the binding one.
This comparison is published by AI Health Index, an independent research platform that compares healthcare AI vendors objectively. Rad AI and Subtle Medical are each graded against the same capability taxonomy, from each vendor's own public materials and the regulatory record, under the AI Health Index verification standard. No vendor pays for placement, and no vendor has reviewed this page. How this evidence is graded
Plain facts
| Fact | Rad AI | Subtle Medical |
|---|---|---|
| Primary category | Radiology & Imaging AI | Radiology & Imaging AI |
| Founded | 2018 | Not recorded |
| Headquarters | Berkeley, California | Menlo Park, California |
| Website | radai.com | subtlemedical.com |
Side by Side
Each record in one paragraph
Written to be quoted whole. Each paragraph states what the AI Health Index verified about the vendor, with the caveats attached. Generated from this pair’s live capability grades, so it moves when a grade moves.
The AI Health Index awards Rad AI its top capability grade on AI Centrality, Autonomy and Oversight Model and EHR and Interoperability Depth. Set against Subtle Medical, Rad AI grades higher on Autonomy and Oversight Model. Grades reflect evidence the AI Health Index could verify at the last review, so a low grade records disclosure the vendor has not published rather than a capability it has been shown to lack.
Source: AI Health Index, August 2026
The AI Health Index awards Subtle Medical its top capability grade on several axes, including AI Centrality, Clinical and Operational Evidence and FDA and Regulatory Status. Set against Rad AI, Subtle Medical grades higher on several axes, including Model Supply Chain Disclosure, Clinical and Operational Evidence and FDA and Regulatory Status. Grades reflect evidence the AI Health Index could verify at the last review, so a low grade records disclosure the vendor has not published rather than a capability it has been shown to lack.
Source: AI Health Index, August 2026
Questions buyers ask
Should we choose Rad AI or Subtle Medical?
On the axes where the AI Health Index separates them, Rad AI grades higher on Autonomy and Oversight Model, and Subtle Medical grades higher on several axes, including Model Supply Chain Disclosure, Clinical and Operational Evidence and FDA and Regulatory Status. Subtle Medical leads on the greater share of scored axes, but the split means the decision turns on which constraint is binding rather than on an overall winner.
Where do Rad AI and Subtle Medical differ most?
The widest separation the AI Health Index records between Rad AI and Subtle Medical is on FDA and Regulatory Status, where Rad AI grades C and Subtle Medical grades A. That axis sits in the Regulatory and Compliance group, so it should carry the most weight for a buyer whose binding constraint is where regulatory exposure sits and who carries it.
Where do Rad AI and Subtle Medical grade the same?
The AI Health Index grades Rad AI and Subtle Medical the same on several axes, including AI Centrality, Model and Technology Transparency and AI Safety and PHI Stewardship. Neither holds an advantage the index can evidence on those axes, so they should not carry weight in a selection between these two.
Related comparisons
Other published head to head assessments involving these vendors or their closest peers. The full set for this category is on the Radiology & Imaging AI page.
These change different parts of the imaging pathway and a department may reasonably run both, so this is a sequencing question rather than a choice. Their failure modes are opposite and only one is visible: a reporting assistant that degrades produces text a radiologist reads and corrects, while a reconstruction model that degrades produces a cleaner image that has lost something no reader will notice. Rad AI holds no clearance for any product in its portfolio, and neither vendor publishes subgroup performance or pricing.