Table 1.

Parameters obtained for constant PMMA SNR/CNR determination. Given the kVp, mA and filtration, as expected the RPAK increases from Low, to Normal to High Fluoro settings.

	Low dose	Normal fluoro	High dose
kVp	74.2	71.3	66.4
mA	125.3	98.7	150.1
Disp RPAK (mGy)	4	9	14
Spectral Filter, Cu (mm)	0.9	0.3	0.3

Abbreviations: SNR, signal to noise ratio; CNR, contrast to noise ratio; PMMA, polymethyl methacrylate; RPAK, reference point air kerma.