Overbeaming in z-axis
For single slice scanners, width of x-ray beam in z-axis is very close to imaged width
For four and greater slice scanners, beam is about 2-3 mm wider than total imaged width
- This is due to non-uniform dose distribution along z-axis
- Equal x-ray beam intensity required for each detector in matrix
For similar image quality in multi-slice, doses are slightly higher than in single slice
- More significant for narrow collimations