Convert NII.GZ to SVG

Technical note

NII.GZ to SVG: what carries over and what does not

The standard NII.GZ header has no fields for a patient's name, birth date or accession number, only an 80-character free-text description, which is one reason research pipelines convert DICOM to NIfTI before data is shared. That does not make every output anonymous. A head scan contains the face, and a 3D rendering of the volume can reconstruct it well enough to recognise someone, which is why public datasets are usually defaced first. Slices that pass through the front of the head carry the same risk. NII.GZ is made of pixels and SVG stores geometry, so the conversion traces the image into paths. Once traced, the artwork scales to any size without softening, which is the point of the exercise. It is a reconstruction rather than the original drawing: curves are fitted to the pixel edges, so the cleaner and sharper the source, the closer the paths follow what the designer intended.