Virtual nonenhanced abdominal dual-energy MDCT: Analysis of image characteristics

Table 1 Subtraction of the average HU measurements of organs evaluated: Enhanced computed tomography minus virtual nonenhanced images

Organ	mean ± SD	P value	Percent deletion
Adrenal gland	1.8 ± 6.9	< 0.0001	55.3
Kidney	30.279 ± 34.91	< 0.0001	61.7
Spleen	9.202 ± 8.79	< 0.0001	34.5
Liver	3.619 ± 9.21	0.490	10.2
Subcutaneous fat	0.330 ± 2.52	0.8318	2.3
Prostate	-0.183 ± 1.63	1.0000	13.3
Erector spinae muscle	-0.403 ± 2.64	0.5235	7.7
Right atrium	135.4 ± 16.0	< 0.0001	51.5
Portal vein	7.6 ± 2.3	0.0015	39.3
Inferior vena cava	1.7 ± 2.0	0.5235	26.6
Aorta	114.1 ± 1.2	< 0.0001	51.6
Iliac vein	3.616 ± 3.04	0.0625	25.3
Iliac artery	104.64 ± 53.66	< 0.0001	55.0

Table 2 Average HU differences in densities of organs evaluated on virtual nonenhanced minus regular nonenhanced images

Organ	mean ± SD	P value
Adrenal gland	20.7 ± 13.5	< 0.0001
Kidney	40.5 ± 6.8	< 0.0001
Spleen	22.3 ± 9.8	< 0.0001
Liver	5.8 ± 6.9	0.0072
Subcutaneous fat	-0.3 ± 4.54	1.0000
Prostate	4.3 ± 6.6	0.5000
Erector spinae muscle	3.3 ± 4.9	0.0169
Right atrium	37.8 ± 16.1	< 0.0001
Portal vein	21.8 ± 12.0	0.0002
Inferior vena cava	12.2 ± 11.6	< 0.0001
Aorta	38.0 ± 9.3	< 0.0001
Iliac vein	8.3 ± 7.9	0.0225
Iliac artery	38.4 ± 15.0	< 0.0001