Chapter 02Discovery insights
20+ clinical interviews, 15+ hospital systems.
We ran structured interviews across three groups: radiologists, referring physicians, and hospital administrators. The pattern was unambiguous: they didn't trust opaque outputs. A model that suggested a finding without showing why got dismissed. A model 15% slower but that surfaced source imagery regions, cited prior scans, and flagged uncertainty got adopted.
✦ What clinicians said
"I won't sign anything I can't defend. Show me what the model saw."
Before committing the team to a full rebuild, I tested the idea on a small group of radiologists first: an early version that showed its reasoning, not just its output. It held up. Only then did we pivot the MVP spec. Interpretability first, speed second, validated on a handful of clinicians before we bet the full build on it.
Chapter 03Engineering & regulatory
Build for adoption, not for demo day.
The rebuilt MVP shipped with region-level evidence highlighting, confidence intervals per finding, one-click model-feedback capture, and an audit log aligned to FDA SaMD requirements. We drove NLP accuracy from 68% to 88% through structured feedback loops: radiologists flagged errors inline, and those corrections flowed back into prompt tuning within the sprint.
The compliance decision: controlled automation over full autonomy. Every AI-generated report drafted, never submitted. Clinician sign-off was the spec, not an afterthought, a clear-cut call FDA SaMD requirements made obvious from the start.
The architecture decision underneath the pivot: retrieval-augmented generation, not a model answering from memory. Every finding had to trace back to retrieved source content, the current scan and cited prior scans, never asserted from general training. In a domain where a hallucinated finding is a patient-safety issue, that scoping was the entire point of choosing RAG over fine-tuning.
Chapter 04Outcome
$500K+ ARR in six months. 4,000+ manual hours eliminated annually.
The platform launched across the client's partner network. ARR surpassed $500K within six months, faster than the original velocity-first spec projected, because adoption was the constraint, not feature count. Downstream, the structured data pipeline we designed eliminated 4,000+ manual hours per year of post-processing across partner sites.
Chapter 06Lessons
What this taught me about trust.
Interpretability beats speed in clinical AI. Radiologists adopted the one they could defend to a patient, not the faster one.
Compliance and adoption aren't separate asks. The audit log and clinician sign-off FDA SaMD required were also what built the trust that drove adoption.
Feedback loops beat one-time accuracy pushes. 68% to 88% came from making every clinician correction traceable back into prompt tuning within the same sprint.