Table 1.

Comparison of first-, second-, and third-generation dual-source CT.

Main parameter	First generation	Second generation	Third generation
Minimum frame rotation time (s)	0.33	0.28	0.25
Time resolution (ms)	83	75	66
Max scan speed (cm/s)	20.0	45.8	73.7
Maximum number of image layers (layer)	64	128	96
Optional kV value (KV)	80.100.120.140	70.80.100.120.140	70.80.100.120.140.150
Imaging vision (cm)	26	33	50
Ball tube max. power (kW)	2 × 80	2 × 100	2 × 120
Maximum collimation beam width (mm)	19.2	34.8	52.5