Prog Med Phys.  2016 Jun;27(2):72-78. 10.14316/pmp.2016.27.2.72.

Characteristics of CCD Based Optical CT Scanner for Therapeutic Radiation Dosimetry

• Lee JC
• Kim AR
• Ji YH
• Kwon SI

• KMID: 2328191
• DOI: http://doi.org/10.14316/pmp.2016.27.2.72

Abstract

A CCD camera and an LED light source were combined to fabricate a compact optical CT scanner for the therapeutic radiation dose evaluation of a polymer gel dosimeter. After the collimated beam emitted by the LED passed through aquarium, gel phantom, and telecentric lens, an image was collected by the CCD camera and reconstructed using MATLAB. By using a stepping motor and LabVIEW, the gel dosimeter was rotated at every 0.72°, and the time for collecting 500 slice images per a revolution was within 20 min. At a spatial frequency of 4.5 lp/mm of the optical CT scanner, the modulation transfer function value was 72%. The linear correlation coefficient of the optical CT scanner for the polymer gel dosimeter was 0.987.

Keyword

Optical Computed Tomography Scanner; Polymer Gel; Dosimetry

MeSH Terms

Polymers
Radiometry*
Polymers

Figure

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  Fig. 1. A schematic diagram of OCT Scanner (left) and a picture of OCT on the experiment (right).

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  Fig. 2. Modulation Transfer Function curve. Spatial resolution for a optical CT system is measured to be 72% out to 4.5 lp/mm.

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  Fig. 3. Projection image of a gel dosimeter irradiated with Cyberknife (1 Gy, 2 Gy and 3 Gy).

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  Fig. 4. Dose response curve of a gel dosimeter measured by OCT scanner. The inset shows the linearity to 6 Gy and the linear correlation coefficient of r2=0.987.

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  Fig. 5. Dose response curve of a gel dosimeter using MRI. The linear correlation coefficient is r2=0.997.

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  Fig. 6. Percent Depth Dose distribution measured on the depth of central axis of a polymer gel dosimeter using 6 MV X-ray photon beam.

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  Fig. 7. (a) Sinogram, (b) irradiated gel and (c) isodose distribution.

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  Fig. 8. (a) A bear doll installed in PET container, (b) sagittal projection image (2,456×2,058 pixels, 16 bit), (c) sinogram, (d) line profile at the vertical black line of sinogram and (e) 3-dimensional rendering image.

Reference

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