# How to process example cross beam CT calibration data

This movie illustrates the processing of the cross beam CT calibration data for a 3D polymer gel dosimeter.

The following procedures were applied:

Background

- Importing 20 CT series of a background - non-irradiated polymer gel dosimeter in Dose distribution phantom 1 immersed in a water phantom
- Calculating a mean out of those 20 series of background

Cross beam irradiated dosimeter

- Importing 20 CT series of a polymer gel dosimeter irradiated according to a cross beam calibration pattern; the dosimeter in Dose distribution phantom 1
- Calculating a mean out of those 20 series of an irradiated dosimeter

Subtracting the mean series

- Mean background series were subtracted from the mean irradiated polymer gel dosimeter series

Filtrations

The output series after subtraction procedure were filtered with:

- Mean filtering: 3 mm x 3 mm, 3D, 1 iteration; then,
- FFT/Nuttall: 25 iterations

Note that the time period for the filtration procedures is related to the parameters of a computer, size of the matrix, type and the parameters of a filter chosen. The polyGeVero-CT allows for resizing of a matrix processed.