Abstract: Method and apparatus for management of image data using dynamic image pixel management for composite image display of image data so that "overlayed" and transparent images may be displayed, changed, and redisplayed in real time. On redisplay, the invention returns values of only those pixels, the values of which have changed, or any subset of all pixels. The invention is independent of the hardware used to display images and permits true color with transparency regardless of the number of display hardware bit planes available.

Abstract: An apparatus and method for aligning a radiosurgery/stereotactic radiotherapy system. The system includes a linear accelerator, including a gantry and a collimator, a couch, and a stereotactic reference system mounted on the couch. The apparatus includes a laser measuring device mounted on the gantry, the laser measuring device having a laser generator element for generating a laser light beam and a laser displacement sensor. The apparatus also includes a reference fixture, attached to the stereotactic reference system, having at least one reflective surface for reflecting the laser light beam to the laser displacement sensor, upon which the laser displacement sensor measures the distance between the reflective surface and the laser measuring device.