TABLE II.

For the various segmented detectors (columns 2 –9) and the phosphor screen detector (column 10), CNR results for the liver-equivalent object at 3.08 cGy (CNR_Liver) are shown. The CNR result for the phosphor screen detector was interpolated from the slope of CNR² versus dose results illustrated in Fig. 11. Also shown are MTF results at 0.5 and 1.0 line pair/mm (MTF_0.5 and MTF_1.0) obtained from a previous study of Monte Carlo simulations of radiation energy deposition involving the same segmented detector configurations.⁴⁸ For comparison, MTF results obtained from measurements³⁶ with an MV AMFPI employing a phosphor screen (Lanex Fast B, Eastman Kodak) equivalent to that simulated in the present study are also listed in the last column. Note that, for segmented detectors, the first row indicates the detector thickness and scintillator material, and the second row indicates the septal wall density.

X-ray Detector	10 mm CsI		40 mm CsI		10 mm BGO		40 mm BGO		Phosphor Screen
	Low	High	Low	High	Low	High	Low	High
CNRLiver	1.21	1.12	1.88	1.66	1.40	1.23	2.00	1.80	0.27
MTF0.5	0.41	0.55	0.33	0.46	0.49	0.58	0.39	0.48	0.37
MTF1.0	0.20	0.29	0.15	0.26	0.25	0.33	0.19	0.27	0.12