iaea human health series publications - SEDIM

FIG. 10. Detector crystallization. (a) The arrows in the top left-hand corner indicate a subtle artefact in the mediolateral oblique(MLO) view image that appears to mimic calcification. (b) The subsequent MLO view of the other breast indicates that the artefact isin fact caused by the a-Se detector beginning to crystallize. The window width and window level in this image have been adjusted tohighlight the problem. (c) A more obvious and serious example of a-Se detector crystallization is apparent in this image (see arrows).FIG. 11. The image on the left is a standard craniocaudal (CC) view of a breast, and the image on the right is the MLO view acquiredimmediately afterward. As indicated by the arrows, the CC view is still evident in the latter image. This is a totally unacceptableexample of a-Se detector image lag, caused in this instance by the room temperature not being high enough to maintain the detectortemperature at the required level.32