When you subpoena medical imaging records, you may receive two very different things: a radiology report and a DICOM study. Attorneys sometimes treat these as interchangeable. They are not. Understanding the difference matters for case strategy, expert preparation, and what you bring to deposition and trial.
The Radiology Report: The Radiologist's Written Interpretation
The radiology report is a written document — typically one to three pages — prepared by the radiologist who reviewed the imaging study. It describes what the radiologist observed, their findings, and their impressions or conclusions. It may note the presence of a herniation, a fracture, a mass, or other findings. It may also note what was not found.
The radiology report is the radiologist's professional opinion. It is not the imaging data itself. It is a summary of what one radiologist saw when they reviewed the study at a particular point in time.
The DICOM Study: The Actual Imaging Data
The DICOM study is the actual imaging data — the raw files produced by the MRI machine, CT scanner, or other imaging equipment. A single DICOM study can contain hundreds or thousands of individual image slices organized into series. These are the images the radiologist reviewed when preparing their report.
The DICOM study is not a document. It cannot be opened like a PDF. It requires specialized software to view, and it contains embedded metadata including patient information, scan date, equipment parameters, and technical acquisition data.
Why Both Matter in Litigation
In litigation, the radiology report and the DICOM study serve different purposes. The report tells you what the treating or reviewing radiologist found. The DICOM study is what your expert witness will independently review — and their findings may differ from the original report.
Your expert cannot form an independent opinion from the radiology report alone. They need the actual imaging data. This is why obtaining the DICOM study — not just the report — is essential in any matter where medical imaging is relevant.
What Your Expert Needs
A medical expert witness reviewing imaging for litigation needs the DICOM study, not just the radiology report. They will review the actual images, form their own independent opinion, and may identify findings that differ from — or expand on — the original radiologist's report.
Once your expert has reviewed the study and identified the relevant images or series, those images need to be prepared as a professional image set for deposition, mediation, and trial use.
A Practical Note on Subpoenas
When subpoenaing medical imaging records, specify that you want both the radiology report and the DICOM imaging study. Hospitals and imaging centers sometimes produce only the report unless the DICOM study is specifically requested. The DICOM study may be provided on CD, DVD, or via secure digital transfer depending on the facility.
Lightning Medical provides medical image reproduction and litigation-support services. Lightning Medical does not provide medical diagnoses, radiological interpretations, medical opinions, or legal advice.