Table 1.

Values of normalized CTDI_w at the widest available beam width, for eight commercial CT scanners. N∕A: Not available.

Vendor	Scanner model	CTDIw (mGy∕100 mAs)
		80 kV	100 kV	120 kV	140 kV
GE	HiSpeed CT∕i	1.6	3.6	5.2	7.6
	LightSpeed Plus	2.9	5.6	9.0	12.9
	LightSpeed 16	2.7	5.8	9.1	13.7
	VCT	3.4	6.2	9.5	13.3
Siemens	Somaton Plus 4	2.3	N∕A	7.9	11.4
	Sensation 4	2.5	N∕A	7.7	10.9
	Sensation 16	2.4	4.8	7.6	10.9
	Sensation 64	1.8	4.1	7.0	11.4
Average ±σ		2.5±0.6	5.0±1.0	7.9±1.4	11.5±1.9