Table 6. Effect of Arm Position on Slice Thickness-Normalized Image Noise and Subjective Image Quality.

	Arm Position
	Both Up	Others	P	Both Horizontal	Others	P
Slice thickness-normalized image noise (HU)
Group 1	4.5 ± 0.5 (n = 28)	4.7 ± 0.6 (n = 14)	0.1	4.7 ± 0.4 (n = 7)	4.5 ± 0.6 (n = 35)	0.6
Group 2	4.4 ± 0.6 (n = 25)	4.6 ± 0.7 (n = 16)	0.3	4.6 ± 0.7 (n = 9)	4.5 ± 0.6 (n = 32)	0.6
Subjective image quality grade
Group 1	1.3 ± 0.4 (n = 28)	1.9 ± 0.7 (n = 14)	0.001	2.3 ± 0.5 (n = 7)	1.3 ± 0.5 (n = 35)	< 0.0001
Group 2	1.1 ± 0.3 (n = 25)	2.0 ± 0.5 (n = 16)	< 0.0001	2.2 ± 0.4 (n = 9)	1.3 ± 0.4 (n = 32)	< 0.0001