Table 2.

Scanner and scanning protocol used for both normal subjects and severe asthmatics

	Scanner and Protocol
Scanner model	GE VCT 64 slice
Scan type	Helical
Rotation time(s)	0.5
Detector configuration (channel no. × mm)	64 × 0.625 mm
Pitch	0.984
Peak kilovoltage, kVp	120
Miliampere, mA	S-145
	M-180
	L-270
Dose modulation	Auto mA OFF
Reconstruction algorithm	Standard or Detail
Lung algorithm	None
Additional image filters	No selection
Thickness, mm	0.625
Interval, mm	0.5
Iterative reconstruction (noise reduction algorithm)	No selection
Scan time(s), 30-cm length	<10

mA was varied for Severe Asthma Research Program protocol based on BMI size (small: BMI <20, medium: 20 ≤ BMI ≤30, large: BMI >30).