Table 5-.

Qualitative Scores of 120 kV and 50 keV PCD-CT images for both readers individually and then averaged for the entire cohort, low contrast cohort and routine contrast cohort. Summaries are presented as Mean ± SD.

	Low Contrast Group			Routine Contrast Group			Contrast groups combined
	120 kV	50 keV	p-value	120 kV	50 keV	p-value	120 kV	50 keV	p-value
READER 1
Enhancement	4.4 ± 0.8	4.6 ± 0.6	0.43	4.0 ± 1.1	4.1 ± 0.9	0.83	4.2 ± 1.0	4.3 ± 0.8	0.50
Sharpness	4.2 ± 0.8	4.2 ± 0.8	0.89	4.3 ± 0.9	4.3 ± 0.9	1.00	4.2 ± 0.8	4.2 ± 0.8	0.90
Artifact	4.0 ± 1.1	4.0 ± 1.1	0.88	3.5 ± 1.3	3.5 ± 1.3	1.00	3.8 ± 1.2	3.8 ± 1.2	0.90
Noise	4.7 ± 0.5	4.5 ± 0.6	0.06	4.7 ± 0.6	4.4 ± 0.6	0.06	4.7 ± 0.5	4.5 ± 0.6	0.01
Overall IQ	4.1 ± 1.1	4.1 ± 1.1	0.91	3.7 ± 1.4	3.7 ± 1.3	0.95	3.9 ± 1.3	3.9 ± 1.2	0.99
READER 2
Enhancement	4.0 ± 0.7	5.0 ± 0.2	< 0.0001	4.0 ± 1.0	4.9 ± 0.4	< 0.0001	4.0 ± 0.9	4.9 ± 0.3	< 0.0001
Sharpness	4.1 ± 0.8	4.5 ± 0.9	0.02	4.0 ± 0.4	4.4 ± 0.6	0.02	4.1 ± 0.6	4.4 ± 0.7	< 0.0001
Artifact	4.5 ± 0.8	4.6 ± 0.7	0.80	4.4 ± 0.6	4.5 ± 0.6	0.80	4.5 ± 0.7	4.5 ± 0.7	0.72
Noise	4.5 ± 0.6	4.6 ± 0.5	0.50	4.4 ± 0.5	4.5 ± 0.5	0.60	4.4 ± 0.5	4.5 ± 0.5	0.39
Overall IQ	3.6 ± 0.6	4.7 ± 0.5	< 0.0001	3.6 ± 0.9	4.6 ± 0.6	< 0.0001	3.6 ± 0.7	4.7 ± 0.6	< 0.0001
AVERAGED
Enhancement	4.2 ± 0.6	4.8 ± 0.4	< 0.0001	4.0 ± 0.9	4.5 ± 0.5	0.02	4.1 ± 0.8	4.6 ± 0.5	< 0.0001
Sharpness	4.1 ± 0.7	4.4 ± 0.7	0.16	4.2 ± 0.5	4.3 ± 0.6	0.20	4.2 ± 0.6	4.3 ± 0.7	0.06
Artifact	4.3 ± 0.8	4.3 ± 0.8	0.80	4.0 ± 0.8	4.0 ± 0.8	0.90	4.1 ± 0.8	4.2 ± 0.8	0.80
Noise	4.6 ± 0.4	4.5 ± 0.4	0.51	4.6 ± 0.4	4.5 ± 0.5	0.44	4.6 ± 0.4	4.5 ± 0.4	0.31
Overall IQ	3.9 ± 0.8	4.4 ± 0.7	0.01	3.7 ± 1.0	4.2 ± 0.8	0.04	3.8 ± 0.9	4.3 ± 0.8	< 0.0001

IQ= Image quality