COMPUTED TOMOGRAPHY 9: A second generation CT scanner has a fan of eight beams. For your measurement, you perform 16 translations, of duration eight seconds each, which provides you with a full set of projections. You can assume that the noise in a region of interest (ROH), in the center of a homogeneous water cylinder is proportional to the noise of the total number of photons that penetrated this ROlI under all angles In order to speed up the scan, you decide to rearrange the angle between the eight detectors to accommodate a full set of projections in 12 translations. The duration of each translation is now four seconds. How much larger or smaller does the region of interest (RO12) have to be to allow an evaluation of the density with the same precision as in ROl1? Assume that the time needed for scanner rotation is negligible COMPUTED TOMOGRAPHY 9: A second generation CT scanner has a fan of eight beams. For your measurement, you perform 16 translations, of duration eight seconds each, which provides you with a full set of projections. You can assume that the noise in a region of interest (ROH), in the center of a homogeneous water cylinder is proportional to the noise of the total number of photons that penetrated this ROlI under all angles In order to speed up the scan, you decide to rearrange the angle between the eight detectors to accommodate a full set of projections in 12 translations. The duration of each translation is now four seconds. How much larger or smaller does the region of interest (RO12) have to be to allow an evaluation of the density with the same precision as in ROl1? Assume that the time needed for scanner rotation is negligible