The incidence of the different sources of noise on the uncertainty in radiochromic film dosimetry using single channel and multichannel methods.

The incidence of the different sources of noise on the uncertainty in radiochromic film dosimetry using single channel and multichannel methods.
Phys Med Biol. 2017 Nov 01;62(22):N525-N536
Authors: González-López A, Vera-Sánchez JA, Ruiz-Morales C
Abstract
The influence of the various sources of noise on the uncertainty in radiochromic film (RCF) dosimetry using single channel and multichannel methods is investigated in this work. These sources of noise are extracted from pixel value (PV) readings and dose maps. Pieces of an RCF were each irradiated to different uniform doses, ranging from 0 to 1092 cGy. Then, the pieces were read at two resolutions (72 and 150 ppp) with two flatbed scanners: Epson 10000XL and Epson V800, representing two states of technology. Noise was extracted as described in ISO 15739 (2013), separating its distinct constituents: random noise and fixed pattern (FP) noise. Regarding the PV maps, FP noise is the main source of noise for both models of digitizer. Also, the standard deviation of the random noise in the 10000XL model is almost twice that of the V800 model. In the dose maps, the FP noise is smaller in the multichannel method than in the single channel ones. However, random noise is higher in this method, throughout the dose range. In the multichannel method, FP noise is reduced, as a consequence of this method's ability to eliminate channel independent perturbations. However, the random noise increa...

Source: Physics in Medicine and Biology - November 1, 2017 Category: Physics Authors: González-López A, Vera-Sánchez JA, Ruiz-Morales C Tags: Phys Med Biol Source Type: research