1. National Alliance for Medical Image Computing http://na-mic.org NRRD (“nerd”) format: Nearly Raw Raster Data ASCII header + raw/ascii/gzip datafile(s) NrrdIO: reader/writer in ITK right now Represents scalars, DWIs, tensors, etc. unu: command-line swiss-army knife –unu slice, crop, flip, permute, resample … –“unu make” makes header in one shot General orientation representation Conservative approach to optional info

2. National Alliance for Medical Image Computing http://na-mic.org NRRD0004 content: HUVA51125252 modality:=SPGR dimension: 3 sizes: 256 256 124 type: short endian: big encoding: raw data file: HUVA51125252_spgr.img space: right-anterior-superior space origin: (117.5,-93,119) space directions: (-0.9375,0,0) (0,0,-0.9375) (0,1.5,0) space units: "mm" "mm" "mm" thicknesses: NaN NaN 1.5 centerings: cell cell cell kinds: space space space NRRD in action (for scalar volume) “magic” Array dimension and sizes SPGR data for this BIRN# Location and Orientation in RAS space Encoding on disk (Analyze-friendly) Slice thickness + sample centering (all axes are spatial)

3. National Alliance for Medical Image Computing http://na-mic.org NRRD0004 content: HUVA33202368 modality:=DW dimension: 4 sizes: 256 256 35 7 type: short endian: big encoding: raw data file: HUVA33202368_dwi.img space: right-anterior-superior space origin: (117.5,-93,119) space directions: (-0.859375,0,0) (0,0,-0.859375) (0,5,0) none space units: "mm" "mm" "mm" thicknesses: NaN NaN 4 NaN centerings: cell cell cell none kinds: space space space list DW_gradient_001:= 0.70710677 0.0 0.70710677 DW_gradient_002:= 0.70710677 0.70710677 0.0 DW_gradient_003:= 0.0 0.70710677 0.70710677 DW_gradient_004:= 0.70710677 -0.70710677 0.0 DW_gradient_005:=-0.70710677 0.0 0.70710677 DW_gradient_006:= 0.0 0.70710677 -0.70710677 NRRD in action (for DWI volume) “magic” Array dimension and sizes Diffusion-weighted data for this BIRN# Location and Orientation in RAS space Encoding on disk (Analyze-friendly) Slice thickness + sample centering Diffusion sensitizing gradient directions, also in RAS space Spatial vs. non-spatial axes

4. National Alliance for Medical Image Computing http://na-mic.org Location + Orientation space: right-anterior-superior space origin: (117.5,-93,119) space directions: (-0.859375,0,0) (0,0,-0.859375) (0,5,0) none right anterior superior (RAS) fast medium slow (image)