content: !INTERFILE  :=
  ; This is a sample minimal header for SPECT tomographic data
  ; The format is as per the 3.3 Interfile standard (aside from time frame info)
  
  !imaging modality := nucmed
  
  ; name of file with binary data
  name of data file := SPECT_test_Interfile_header.s
  
  !version of keys := 3.3
  !GENERAL DATA :=
  !GENERAL IMAGE DATA :=
  !type of data := Tomographic
  
  ; optional keywords specifying patient position
  ; patient rotation := prone
  ; patient orientation := feet_in
  
  imagedata byte order := LITTLEENDIAN
  
  number of energy windows:=1
  energy window lower level[1]:=120
  energy window upper level[1]:=160
  
  !SPECT STUDY (General) :=
  ; specify how the data are stored on disk
  ; here given as "single-precision float" (you could have "unsigned integer" data instead)
  !number format := float
  !number of bytes per pixel := 4
  !number of projections := 120
  ; total rotation (or coverage) angle (in degrees)
  !extent of rotation := 360
  process status := acquired
  !SPECT STUDY (acquired data):=
  ; rotation info (e.g. clock-wise or counter-clock wise)
  !direction of rotation := CW
  start angle := 180
  
  ; Orbit definition
  orbit := Circular
  ; radius in mm
  Radius := 166.5
  ; or
  ; orbit := Non-circular
  ; give a list of "radii", one for every position
  ; Radii := {150, 151, 153, ....}
  
  ; pixel sizes in the acquired data, first in "transverse" direction, then in "axial" direction
  !matrix size [1] := 111
  !scaling factor (mm/pixel) [1] := 3
  !matrix size [2] := 47
  !scaling factor (mm/pixel) [2] := 3.27
  
  ; optional keywords specifying frame duration etc
  ; These are not according to the Interfile 3.3 specification
  ; Currently only useful in STIR for dynamic applications
  ; (but a "time frame" is considered to be all projections acquired at the same time)
  ;number of time frames := 1
  ;image duration (sec)[1] := 0
  ;image relative start time (sec)[1] := 0
  
  !END OF INTERFILE :=
  