Modelling optical scattering artefacts for varying pathlength in a gel dosimeter phantom
Modelling optical scattering artefacts for varying pathlength in a gel dosimeter phantom
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DOI:
10.1088/0031-9155/54/2/007
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发表时间:
2009-01-21
影响因子:
3.5
通讯作者:
Baldock, Clive
中科院分区:
文献类型:
--
作者:
Bosi, Stephen G.;Brown, Saxby;Baldock, Clive
A gelatin phantom containing an optically scattering funnel-shaped region of elevated optical density (OD) was used to examine light-scattering-induced artefacts in a cone-beam optical CT scanner used for gel dosimetry. To simulate polymer gel dosimeters, the opacity was introduced by adding a colloidal scatterer to the gelatin. Scatter results in an underestimate of OD (hence dose). In line profiles of OD taken from 3D reconstructions of the funnel, those profiles with a long pathlength through high OD regions exhibited a 'dishing' (or 'cupping') artefact, while those of short pathlength exhibited the opposite effect-'doming'. These phenomena are accounted for by a model that includes the effect of stray, scattered light.