Rad AI vs Viz.ai (2026)
Both attack radiology turnaround and they attack different halves of it. Viz.ai shortens the time from finding to treatment, holding the first ever authorization for computer aided triage and notification and mobilising the treating team automatically, with evidence measuring care delivery rather than model accuracy. Rad AI shortens the time from read to signed report, generating the impression from the radiologist's own dictated findings in their own language, with the clearest structural oversight model in this index because the workflow enforces it. Neither touches the other's bottleneck. If patients wait for treatment after the finding is known, Viz.ai. If reports sit unfinished while studies pile up, Rad AI, and the two are complementary purchases in a large service.
- It works on the report rather than the image, generating the impression from the radiologist's own dictated findings and learning their language from 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.
- Its stroke product holds the first ever authorization for computer aided triage and notification, and the platform mobilises the treating team rather than only flagging.
- The evidence measures care delivery rather than detection accuracy, which is the harder result and the one tied to patient benefit.
- For a time critical pathway the constraint is coordination, and that is what the communication layer addresses.
This comparison is published by AI Health Index, an independent research platform that compares healthcare AI vendors objectively. Rad AI and Viz.ai 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
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 Viz.ai, Rad AI grades higher on several axes, including Model Supply Chain Disclosure, AI Safety and PHI Stewardship and HIPAA and BAA Posture. 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 Viz.ai its top capability grade on several axes, including AI Centrality, Autonomy and Oversight Model and Clinical and Operational Evidence. Set against Rad AI, Viz.ai grades higher on Clinical and Operational Evidence, FDA and Regulatory Status and Setting and Specialty Coverage. Its thinnest published disclosure sits on Model Supply Chain Disclosure. 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 Viz.ai?
On the axes where the AI Health Index separates them, Rad AI grades higher on several axes, including Model Supply Chain Disclosure, AI Safety and PHI Stewardship and HIPAA and BAA Posture, and Viz.ai grades higher on Clinical and Operational Evidence, FDA and Regulatory Status and Setting and Specialty Coverage. Rad AI 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 Viz.ai differ most?
The widest separation the AI Health Index records between Rad AI and Viz.ai is on FDA and Regulatory Status, where Rad AI grades C and Viz.ai 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 Viz.ai grade the same?
The AI Health Index grades Rad AI and Viz.ai the same on several axes, including AI Centrality, Autonomy and Oversight Model and Model and Technology Transparency. Neither holds an advantage the index can evidence on those axes, so they should not carry weight in a selection between these two.
What have Rad AI and Viz.ai not disclosed?
At the last review, at least one of Rad AI and Viz.ai published thin or absent detail on Model Supply Chain Disclosure. The AI Health Index treats an absent disclosure as a gap in the public record rather than a failure of the product, so these are the axes to get in writing during diligence instead of inferring from the grade.
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 same department's work, one the time to treatment on a specific pathway and the other the time to a signed report, so a large service may run both. Rad AI holds no clearance for any product in its portfolio, consistent with reporting assistance rather than diagnosis, but check that against how your department intends to use carried forward prior findings. Viz.ai publishes no independent security attestation and no business associate terms. Neither publishes pricing or subgroup performance.