Power settings were 120 kV, auto milliamperage
, matrix of 512x512 pixels, collimation 64x1.25 mm, slice thickness 1.25 mm, and pitch 0.984:1.
The image quality of devices using the cone-beam geometry varies according to acquisition parameters such as milliamperage
, kilovoltage, and voxel size.
CT images were taken with 2 mm thickness with a pitch of 1: 1.1, 16 x 0.5 mm detector configuration, at 120 peak kilovoltage (kVp) and a variable milliamperage
using an effective mAs of 100 mA.
CT was obtained with the following parameters: rotation time, 0.6 s; 2.5 to 5 mm thick sections with the possibility of back-reconstructions up to 0.6 mm; automatic milliamperage
(mA) (min 300 mA, max 450 mA), and 120 kV.
The CBCT units are manufactured with fixed exposure settings or can also be manually adjusted in relation to the peak kilovoltage (kVp) and/or milliamperage
requirements for supramaximal stimulation of the ulnar nerve with surface electrodes.
Influence of cone-beam computed tomography milliamperage
settings on image quality of the mandibular third molar region.
General technical ALARA strategies to reduce exposure include: 1) weight-based protocols for radiation parameters (eg, kilovoltage, kV; milliamperage
, mAs); and, 2) body and selective organ protective shielding.
Close proximity is obtained by ensuring that a twitch response is obtained at a low milliamperage
current (typically [less than or equal to] 0.3 mAmps in our institution).
Several academic studies suggest that low electrical current (LEG) disrupts cell membranes and enzymatic activities in both yeast and bacteria, and during the course of several years, the researchers have learned a good deal about the effects of different levels of milliamperage
and types of electrodes.
Exposures were made at 70 kVp (kilovoltage peak) and 7 mA (milliamperage
) on Kodak DF58 Ultraspeed periapical film using the Gendex GX 770 Intraoral X-ray System.
Automatic exposure control is available on some upper-end machines, measuring the amount of radiation passing through the mandible during the beginning of the exposure and adjusting the kilovoltage peak, milliamperage
and tube-film speed to obtain a well-exposed image.