DICOM, JPEG, and what an export quietly loses
Exporting a study to JPEG is convenient and occasionally costly. What actually changes when images leave their native format.
Most clinics have, at some point, exported a study to JPEG to email it somewhere. It works. But it is worth understanding what the convenience costs, because the loss is not always visible on your own monitor.
Bit depth is the main casualty
Native DICOM from a digital radiography system typically carries 12 to 16 bits per pixel — thousands of distinguishable grey levels. A standard JPEG carries 8 bits: 256 levels.
On a well-windowed image, that difference is often invisible, because the window you chose has already selected the range that matters. The problem is that it fixes that choice permanently. A reader receiving the JPEG cannot re-window to examine soft tissue after you optimised for bone, because the data to do so is gone.
Compression artefacts imitate pathology
JPEG compression works by discarding information the eye is unlikely to miss in a photograph. Radiographs are not photographs. At aggressive compression settings, the blocking and ringing artefacts that result can produce subtle textures in lung fields and at bone margins that look like findings.
If you must export to JPEG, use the highest quality setting your system offers, and never re-save an already-compressed file.
The metadata goes too
A DICOM file carries acquisition parameters, the study date, patient identifiers, laterality markers, series ordering and calibration data. A JPEG carries pixels.
That means measurements may no longer be reliable, series can arrive out of order, and side markers have to be inferred from what is burned into the image — if anything was.
What we recommend
Send DICOM when your system can export it. SINAX handles DICOM natively for every modality, including full CT and MRI series with their metadata intact.
Where DICOM is genuinely not available, export at full resolution and maximum quality, verify that laterality markers are visible in the exported image, and include the acquisition parameters in the case notes.
Convenience is a reasonable trade to make. It is only a bad trade when nobody realised they were making it.
A note on scope. SINAX provides specialist interpretation of diagnostic images. Our reports are advisory and do not replace clinical examination — the final treatment decision always rests with the attending veterinarian.