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Overview
Tomograph files are used when the user desires simulations of the same object using different tomographs (e.g., testing multiple collimator geometries to see which gives the best combination of sensitivity and resolution). Each tomograph file specifies a collimator parameter file, a detector parameter file, and a binning parameter file. The output from a single run of the PHG is used as input to each of the tomographs. This can significantly improve computational efficiency, as the PHG uses the great majority of cpu time for most simuations.
Features
The user can specify up to 100 different tomograph files for each run. There are three restrictions:
- Not compatible with multiple binning parameter files: Only one binning parameter file may be specified per tomograph file: if multiple binning sets are desired for the same tomograph, a tomograph file must be given for each set of binning parameters.
- The tomograph files must use the same type of collimator and detector: For example, if one tomograph file specifies a Monte Carlo PET collimator, all must do so. The parameters for the collimator may change from file to file, but not the type.
- The user may not mix tomograph parameter files with collimator/detector/binning parameter files in the run file: No collimator, detector, and binning parameters files may be specified in the run parameters file if one or more tomograph files are specified. The collimator, detector, and binning parameters are specified in the tomograph files.
Activating Tomograph Files
To activate tomograph files, edit the PHG run-time parameters file and enter file names in 'tomograph_params_file' fields:
STR tomograph_params_file = "a.mytomofile"
Then create (or modify) tomograph parameters files as described below.Note: you can specify up to 100 tomograph parameter files in the PHG run-time parameters file.
[top of page] [example tomograph parameter file]
Tomograph file syntax
Each tomograph parameter file gives the names of a collimator parameter file, a detector parameter file, and a binning parameter file. Tomograph parameter files have the same structure as other SimSET Parameter files:
DATA_TYPE parameter_name = value As each of the three parameters is a file name, DATA_TYPE is always STR. The parameter_name will be collimator_params_file, detector_params_file, or bin_params_file. The value will be the file name. Click on the link below for an example.
The following two links give an example of a run file that uses several tomograph parameter files (the tomograph files are specified near the bottom) and an example of a tomograph parameter file:
Last revised by: Robert Harrison Revision date: 2 Oct 2001
