You plan to take an AP x-ray of the lumbar spine. You plan to perform this without a grid, with a small focal spot size,

[answerhappygod]

You plan to take an AP x-ray of the lumbar spine. You plan to
perform this without a grid, with a small focal spot size, and a
source to image distance of 100cm. You plan to use a kV of 90, mA
of 40 and time of 0.2 seconds. When you run through this with your
supervisor, he suggests that you use a grid to reduce scatter
radiation, and use a large focal spot and a source to image
distance of 180cm to improve image quality. What is the new kV, mA,
and time that you should use for this image? (Bucky factor of
4)