The optimal optical readout for the x-ray light valve--document scanners.
The x-ray light valve (XLV) is a novel, potentially low-cost, x-ray detector that converts an x-ray exposure into an optical image stored in a liquid crystal cell. This optical image is then transferred from the liquid crystal cell to a computer through an optical-to-digital imaging readout system. Previously, CCD-based cameras were used for the optical readout, but recently it was proposed that an inexpensive optical scanner, such as an office document scanner, is a better match to the optical properties of the XLV. A methodology for characterizing a document scanner's ability to produce medical quality images from the XLV is outlined and tested on a particular scanner (Canon LiDE 30). This scanner was shown to have key characteristics of a medical device-a linear response, dynamic range sufficient for chest radiography (although not mammography) in a single pass, and an MTF and NPS that exceed the requirements for all medical applications of the scanner. This combination of criteria shows that a document scanner can be used as a digitization method for the XLV.
Oakham
P
P
Imaging Research, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
MacDougall
Robert D
RD
Rowlands
J A
JA
D002138:Calibration; D004867:Equipment Design; D004864:Equipment and Supplies; D006801:Humans; D008327:Mammography / Q000379:methods; D015233:Models, Statistical; D055095:Optics and Photonics; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D012984:Software; D013997:Time Factors; D014584:User-Computer Interface; D014965:X-Rays