Table 1:

Head CT examination parameters^a

Patient Age (yr)	A or H	Rotation (sec)	Collimation (mm)	Section (mm)	Reconstruction Kernel	kVp	Pre-ASIR (mA)	Post-ASIR (mA)
Brain
0–2b	A	0.5	20	5	Soft and bone	100	280	150
2–5		1					200	120
6–10							220	130
11–18							240	140
≥19						120	200	105
Sinus
≥19	H	0.5	40	2.5	Soft and bone	120	NI = 7.5	155
0–18						100	220	130
Orbits
0–18c	Hd	0.5	20	1.25	Standard and bone	100	240	155
Temporal bone
≥19	H	1	20	1.25	Standard and bone	120	250	150
2–18		0.5				120	400	230
Maxillary bone
≥19	Hd	0.5	20	2.5	Standard and bone	120	NI = 7.5	NI = 9.25
0–18	H					100	300	180

Note:—A indicates axial; H, helical; NI, Noise Index; SFOV, scan FOV.

^aAll protocols were imaged with a SFOV using “Head” unless otherwise indicated. All helical acquisitions were scanned with a pitch of 0.984 unless otherwise indicated.

^bSFOV used “Ped Head.”

^cSFOV used “Small Head.”

^dPitch = 0.516.