A technologist performed a portable KUB using a 40 inch SID, 5:1 grid, 85 kVp and 20 mAs. 

When critiquing the image, it was noticed that the image lacked sufficient contrast, and had a long scale of gray which obscured some anatomy. There also appeared to be less density over the whole image than expected, and the spine was not centered to the IR. It had to be repeated, but first the technologist had to see which technical factors should be changed to improve image quality. 

Critical Thinking: 

Was the correct grid ratio used? Why or why not? 

If a change of grid is needed, describe the technical factors that should be selected. Consider that you always want to try to minimize dose to the patient. 

What caused the overall decrease in density and how does that relate to the fact that the spine is off to one side of the image?