FIG. 4.
Projection images and corrections. Raw projection images (A, D, G, and J), flood field corrected projection images (B, E, H, and K), and line profiles (C, F, I, and L) along dotted lines in raw and flood field corrected images from the CCD scanner for the unirradiated PRESAGE™ insert (top panel), single rectangular beam treatment (second panel), parallel-opposed treatment (third panel) and IMRT treatment (bottom panel). Background inhomogeneities and light attenuating static impurity specs were eliminated by flood field correction of raw images.