Ground truth that names everyone who touched it.
Nitsor is a DICOM viewer and a 3D segmentation tool in the browser, which means you mark the region a structure occupies rather than draw a box around it. A radiologist draws, a second reader accepts or rejects, and the dataset you hand your model team names every person who touched it. The scans stay in your own storage.
QIN-Prostate · T2 axial · slice 16
30 slices · 3 mmreal scan
What a model team gets
A label with two names on it
Who drew it, who accepted it, when, and what it replaced. When a reviewer disagrees, the rejection stays in the record instead of vanishing.
A dataset you can version
Branch it, retrain, compare. A change reads as volume and boundary in millimetres, so you can see what moved between v3 and v4 of your ground truth.
Patient data that does not travel
The series stay in your own storage for the whole job. The browser reads only the bytes it needs. We keep an index and a hash, never a copy of the pixels.
How a study moves through it
- 01 · register
Point at the series
DICOM, read from your own storage. Series stay lined up, so a follow-up study sits on the same grid as the first one.
- 02 · label
Segment in 3D
A 512-slice series opens without waiting for the whole file. Brush, erase and grow a region at full resolution.
- 03 · review
A second reader decides
The reviewer sees the difference in millimetres, not a file diff, and accepts or rejects with a reason attached.
- 04 · release
Freeze it and hand it over
One file naming every contour, the reader who drew it, the reader who accepted it, and a hash chain that ties the release to the data it came from.
Formats and connections
| Topic | What it takes |
|---|---|
| Studies in | DICOM, part 10, uncompressed, read from your own storage. The acquisition details survive the import. |
| What comes out | A release: one file with the label events in order, the people and model versions behind them, and a hash chain. Your ethics committee reads it without seeing a single pixel. |
| Where the data sits | Your own S3-compatible storage, in the region you chose. Signed reads go straight to the browser and expire. |
| Who can write | People, models and agents each write with limits you set, under named accounts. Read-only collaborators are free and unlimited, so a colleague at another hospital can look without a paid seat. |
| Sign-on | Provider-neutral, so your identity provider is a swap rather than a rebuild. |
| During a demo | Your scans stay in your own storage. We read the slices on screen from your bucket. The viewer runs on our hosted instance. The pixels do not. |
The worked example on this site
The MRI on this site is QIN-PROSTATE-Repeatability from The Cancer Imaging Archive. It is a repeatability study, so the same patient is imaged twice in one sitting. That makes it a fair test of whether two labelling passes agree, which is the question a model team actually cares about.
We use the T2 axial series, 30 slices at 3 mm, with the study's own DICOM SEG labels. Nothing here is redrawn by us. On a call we can run the same walk on a series of yours, and your data stays in your storage while we do it.
QIN-PROSTATE-Repeatability, TCIA. CC BY 4.0, doi:10.7937/K9/TCIA.2018.MR1CKGND.
slice 12 real scan slice 16 real scan 
slice 20 real scan
- Series
- T2 axial
- Slices
- 30
- Slice spacing
- 3 mm
- Labels
- the study's own DICOM SEG
- Licence
- CC BY 4.0
- Source
- TCIA
What we do not claim
We make no compliance claim. We have not named a standard, been audited against one, or been cleared by a regulator, and we will not imply otherwise on a call. What we can describe is where your data sits, who touched each label, and what an export contains.
Two things your data protection officer will ask, answered before they ask. Viewing, validating and converting can need temporary copies, so source data staying in place does not mean no byte is ever read. And if somebody took our whole database and none of your storage, they would have file paths, a column of checksums, and outlines in millimetres with names attached. That is not nothing, and we will not pretend otherwise. It is also not your scans.
There is no connection to your picture archive today, so you bring studies into object storage yourself. Ask us for the current list on the call, and we will read it to you from product status rather than from a slide.