Claude Opus 4.8 reports intact subscapularis tendon on 266 MB DICOM MRI, contradicting Grade III tear diagnosis

The user uploaded the full DICOM series to Claude Code running Opus 4.8 after receiving shockwave therapy and Traumeel injection. The model executed pydicom and numpy pipelines over one hour to generate a 7.72 MB PDF report. It flagged zero discrete tear despite the clinical note of >50% width involvement.

Comparison against the original report plus ChatGPT 5.5 Pro movement testing produced a second 4.52 MB arbitration PDF. The arbiter assigned moderate-to-high confidence to the LLM reading and stated no evidence supported partial- or full-thickness tear. The discrepancy centers on slice selection and contrast thresholds rather than model hallucination.

Human radiologists receive full clinical context and prior imaging; the model received only the symptom phrase "right shoulder pain for 2–3 weeks." This constraint plus lack of FDA-cleared validation for LLM DICOM interpretation limits immediate clinical substitution. Operational deployment would require DICOM-native guardrails and radiologist-in-the-loop review before any treatment change.

Next steps include repeat MRI at 8 weeks with quantitative T2 mapping and independent musculoskeletal radiologist second read to establish ground truth against the model's output.