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Characteristics relevant to portal dosimetry of a cooled CCD camera‐based EPID
Author(s) -
Franken E. M.,
de Boer J. C. J.,
Barnhoorn J. C.,
Heijmen B. J. M.
Publication year - 2004
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.1785893
Subject(s) - dosimetry , optics , image sensor , physics , radiation , nuclear medicine , image quality , dynamic range , computer science , computer vision , medicine , image (mathematics)
Our EPIDs have recently been equipped with Peltier‐cooled CCD cameras. The CCD cooling dramatically reduced deteriorating effects of radiation damage on image quality. Over more than 600 days of clinical operation, the radiation induced noise contribution has remained stable at a very low level (1 SD⩽0.15% of the camera dynamic range), in marked contrast with the previously used noncooled cameras. The camera response (output signal versus incident EPID radiation exposure) can be accurately described with a quadratic function. This response reproduced well, both in short and long term (variation <0.2% respectively <0.4% (1 SD)), rendering the cooled camera well‐suited for EPID dosimetry applications.