Table 1.

Imaging parameters for six phantoms for routine brain CT examinations^a

Phantom	Rando	Anthropomorphic
Weight (kg)	70	10	30	50	70	90
Average tube currents (mA)	400	250	300	350	400	400
Rotation arcs (°)	420	360	360	420	420	420
Rotation time (s)	1.0	0.75	1.0	1.0	1.0	1.0
CTDIvol (mGy)	69.2	42.7	51.1	60.1	69.2	69.2
Scan length (cm)	12.5	6.4	9.2	10.8	12	14.4
DLP (mGy cm)	896.8	302.2	517.8	666.3	896.8	996.5

^aCurrent tube voltage setting at 120 kVp, collimator 10 mm, beam pitch 1.