Convert NII.GZ to TIFF

Technical note

What changes when you convert NII.GZ to TIFF

Converting NII.GZ to TIFF keeps the volume together. reaConverter writes a multi-page OME-TIFF with one page per slice, stores voxel values in their original data type instead of rescaling them to 8 bits, and carries the voxel size and the rest of the header in the OME-XML metadata. Fiji, napari and other Bio-Formats-based tools open it as a calibrated stack with distances in millimetres, and any ordinary TIFF reader can still page through the slices. 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.