Table 1:

Technical parameters for different CTA examinations

Scan Parameters	Protocol 1: Cerebral Scan with AEC	Protocol 2: Cervicocerebral Scan without AEC
Topogram	120 kV(p), 35 mAs	120 kV(p), 60 mAs
Premonitoringa	120 kV(p), 40 mAs	120 kV(p), 40 mAs
Monitoringb	120 kV(p), 40 mAs	120 kV(p), 40 mAs
Tube voltage (kV[p])	100	120
Effective mAs/quality ref. mAs	148/160	160 (constant tube current)
Pitch factor	1.20	1.20
Rotation time (sec)	0.5	0.33
Acquisition	64 × 0.6 mm	64 × 0.6 mm
Slice collimation (mm)	0.6	0.6
Section width (mm)	4.0	5.0
Scan range (cm)	19	41

^aOne section scanned at the level of aortic arch.

^bFive sections scanned at the level of aortic arch.