complex that additionally is capable of performing both single and dual kv u201c dual energy u201d imaging the proposed scatter elimination technique using a coarse high transparency grid 32 or crossed coarse grids as opposed to fine granularity relatively low transparency grids the shadow mask 36 containing both absorbing elements for scatter estimation and spatially varying filtration for dual energy imaging for the purpose of correcting beam hardening artifacts the use of a shadow mask 36 that can be left in place during the diagnostic scan and methods for estimating the residual scatter and reconstructing the resulting data the use of a low current scout scan to determine the appropriate detector offset in addition to estimating appropriate exposure time appropriate exposures are presently estimated using a scout scan the use of a detector that is smaller than necessary in conjunction with apparatus for moving the detector 30 relative to the source 26 and an appropriate x ray collimator 28 to improve the precision of measurements by reducing scatter and by measuring some portions of the object twice relative to others adapting the measurement system x ray collimation and detector position dynamically to the size of the object to accomplish the above objectives i e appropriate detector position for each frame is not estimated from scout scan but rather from previous frames estimating the pedestal or dark signal for each channel that does not require turning off the x ray source 26 or acquiring additional u201c blank u201d frames between x ray exposures u201c dithering u201d the position of the detector 30 in order to reduce visually disturbing artifacts generating u201c panoramic u201d or conventional linear tomography images from the reconstructed ct volume extensive simulations and a.