Table 4. Doses for tissues and organs positioned within and at the boundaries of the scan length in adult and paediatric chest CT examinations with CT scanner A.

	Adult CT				Paediatric CT
Tube voltage (kV)	120	120	120	120	120	120	120	120
Rotation time (s rotation–1)	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
Beam width (mm)	1.0 mm × 16	1.0 mm × 16	1.0 mm × 32	1.0 mm × 32	1.0 mm × 16	1.0 mm × 16	1.0 mm × 32	1.0 mm × 32
Pitch factor	0.938	1.438	0.844	1.406	0.938	1.438	0.844	1.406
Effective mAs	100	100	100	100	50	50	50	50
Planned scan length (mm)	305	305	305	305	205	205	205	205
Exposed scan length (mm)	340	356	364	400	240	256	264	300
Tissue or organ	Organ dose (mGy)				Organ dose (mGy)
Salivary glands	–	–	–	–	1.5	2.2	2.8	6.7
Thyroid	21.9	24.1	21.5	25.1	11.6	11.6	10.8	13.2
Lung	15.4	15.7	14.1	14.2	10.6	11.2	10.6	10.7
Breast	10.5	7.2	9.7	11.1	8.3	7.3	8.4	9.4
Oesophagus	14.5	14.4	13.6	14.3	10.7	10.8	10.2	10.3
Liver	12.5	12.5	12.3	13.2	9.6	10.5	10.0	10.2
Stomach	12.9	15.3	13.2	11.9	5.2	6.6	6.8	8.6
Colon	1.1	1.4	1.4	2.0	0.6	0.8	0.8	2.5