• 4D MetaIO, Nifti, Nrrd files
  • Enhanced DICOM IODs
  • Sequential and interleaved DICOM series
  • Siemens Mosaic, UIH Grid/VFrame
  • Set of 3D images, having same geometry and data type, can be interpreted as 4D image
Fig. 1
Fig. 2

Create 4D image from set of 3D images

Images must have same data type, dimensions, orientation, origin and spacingThe operation doesn't change data of images or generate new data, group identification number will be assigned to 3D imagesFor images opened from 4D file (MetaIO, Nifti, Nrrd) group identification will be assigned during load
  • Select one of 3D images
  • Open 3D+t toolbar
  • Click g button [1, 2]
  1. Play button or f button (plot pixel intensities) will have same effect, application will try silently create 4D image group
  2. Level/window, LUT and region of selected image 3D image will be applied to 4D image group

Order of frames (3D images) in 4D image

  • Sorted by acquisition time, if available [3]
  • Sorted by instance number, if available and acquisition time is not available [3]
  • Sorted by internal image ID, if neither acquisition time nor instance number are available

3. Applicable to DICOM images

Remove 4D group

  • Open 3D+t toolbar
  • Click X button [4, 5]

4. Applicable to all loaded images

5. Default level and window will be restored

Start 3D+t animation

  • Open 3D+t toolbar
  • Click 3D+t Play button [6]

6. Selected region, window, level and LUT can be adjusted during animation is running

Frame rate

  • Set manually - default 120 ms
  • Check Acq. checkbox to use acquisition time, if available [7]

7. If acquisition times are not available animation will run at manually selected rate

Plot pixel intensities

Fig. 3
  • Open 3D+t toolbar
  • Click f button [8, 9]
  • Click at selected pixel or hold left mouse button and move
  • If check box right of f button is checked - range is relative (min and max of selected pixel)
  • If check box right of f button is unchecked - range is absolute (min and max of 4D image)
  • Click at a graph or hold left mouse button and move to see frame and value

8. Also possible during animation is running

9. Data representation make sense if patient was in quiescence during acquisition

Save 4D image

  • Edit -> Save 4D image
  • Select format by extension, e.g. MetaIO (.mha), Nifti (.nii, .nii.gz), Nrrd (.nrrd)