Table 2.

Mean Hounsfield unit (HU) values and objective image noise (SD) ± standard deviation of standard of care and reduced dose CT series (0.25, 0.4 and 0.8 mGy) for iterative reconstruction techniques [SafeCT (MedicVision^®, Tirat Carmel, Israel), adaptive statistical iterative reconstruction (ASIR; GE Healthcare, Waukesha, WI) and model-based iterative reconstruction (MBIR; GE Healthcare)]

		ASIR40	ASIR70	ASIR90	SafeCT-CH0	SafeCT-CH1	MBIR	p-value
Descending thoracic aorta
Standard of care CT	HU	206 ± 97
	SD	16 ± 5
0.25 mGy	HU		147 ± 92	146 ± 91	146 ± 91	144 ± 91	55 ± 101	0.003
	SD		55 ± 13	49 ± 13	59 ± 13	48 ± 12	40 ± 15	<0.001
0.4 mGy	HU		148 ± 58	148 ± 58	147 ± 58	147 ± 57	138 ± 58	0.9
	SD		40 ± 10	34 ± 9	43 ± 11	34 ± 9	18 ± 7	<0.001
0.8 mGy	HU		131 ± 52	131 ± 52	131 ± 52	130 ± 52	130 ± 53	0.9
	SD		27 ± 9	22 ± 8	29 ± 10	21 ± 8	16 ± 4	<0.001
Tracheal air
Standard of care CT	HU	−938 ± 21
	SD	25 ± 13
0.25 mGy	HU		−814 ± 123	−814 ± 124	−815 ± 125	−814 ± 131	−757 ± 146	0.5
	SD		67 ± 22	66 ± 21	65 ± 21	60 ± 22	28 ± 12	<0.001
0.4 mGy	HU		−933 ± 36	−933 ± 36	−934 ± 36	−935 ± 37	−916 ± 42	0.4
	SD		52 ± 18	51 ± 17	47 ± 17	40 ± 18	23 ± 12	<0.001
0.8 mGy	HU		−947 ± 22	−947 ± 22	−946 ± 23	−947 ± 22	−941 ± 23	0.8
	SD		37 ± 12	36 ± 12	33 ± 15	27 ± 13	18 ± 12	<0.001

CH0 and CH1 are two settings of SafeCT.