TABLE 3.

Differences in Hounsfield Unit Values Between Definition AS Plus (Siemens Healthcare) and Volume CT (GE Healthcare) 64-MDCT Scanners for the Nine Anatomic Soft Tissue Sites Studied

Anatomic Site	No. of Scans	Difference in Hounsfield Unit Measurements Between Scanners
		Mean	SD	Standard error	Median	Minimum	Maximum	Interquartile Range	pa	pb
Right lobe liver	45	−2.9	8.2	1.2	−1.6	−22.3	22.5	10.7	0.023	0.022
Spleen	48	−6.6	6.0	0.9	−6.1	−28.0	3.4	7.6	< 0.0001c	< 0.0001
Right renal cortex	47	−4.1	6.0	0.9	−3.1	−21.8	10.2	7.4	< 0.0001	< 0.0001
Left renal cortex	44	−3.8	4.9	0.7	−3.9	−12.0	9.9	6.6	< 0.0001	< 0.0001
Right psoas muscle	47	−3.3	7.0	1.0	−4.0	−24.6	25.0	7.6	< 0.0001c	0.003
Left psoas muscle	47	−5.4	6.4	0.9	−5.3	−24.3	8.5	6.9	< 0.0001c	< 0.0001
Midline anterior subcutaneous fat	47	10.5	9.0	1.3	11.0	−11.0	32.0	10.0	< 0.0001	< 0.0001
Right posterolateral flank subcutaneous fat	48	−6.0	7.9	1.1	−5.4	−38.8	7.3	6.9	< 0.0001c	< 0.0001
Left posterolateral flank subcutaneous fat	48	−6.0	9.0	1.3	−4.6	−42.9	15.4	7.9	< 0.0001c	< 0.0001

^aWithout adjustment for age or sex obtained using either the two-sided paired Student t test or two-sided Wilcoxon signed rank test.

^bAfter adjustment for age or sex.

^cTwo-sided Wilcoxon signed rank test.