Chapter A - GENERAL & TECHNICAL DATA
A-12 Planmeca ProMax
PROMAX 3D: CTDI VALUES
Technical Manual
6 PROMAX 3D: CTDI VALUES
The following dose information was measured using a dosimetry phantom (head phantom)
that is compatible with the specification in international standard IEC 60601-2-44.
The dosimetry phantom consists of a PMMA cylinder with a diameter of 160mm. The length of
the phantom is 160mm. The phantom is no longer than the sensitive volume of the radiation
detector used for the measurements. The phantom contains holes just large enough to accept
the radiation detector. The holes are parallel to the axis of symmetry of the phantom and the
centres of the holes are located at the centre and 10mm below the surface of the phantom at
90° intervals.
Values were obtained using a dose meter manufactured by Radcal Corporation. Values are
presented in milligray (mGy), except in items b) and c) where values are normalized accord-
ingly. Values are shown separately for 3D and 3Ds sensors. Values for 3Ds sensor are
enclosed in brackets.
Dose measurement process is as follows. First the CT conditions of operation are set. These
conditions of operation include the parameters given in the following table:
After the conditions of operation have been set, the dose meter is placed inside the phantom,
the dose meter display is reset and exposure is commenced. Dose meter display is recorded
after the exposure.
Parameter Range of possible values
Radiation source tube current (mA) 1...14
(1...14)
Radiation source acceleration voltage (kV) 50...90
(50...90)
X-ray beam collimation height = lower / upper / full
width = half / full
(height = lower / upper / full
child patient = on / off)
Exposure mode low dose / normal / high resolution
(low dose / normal / high resolution)
3D sensor
3D s sensor
3D_sensor.eps
3Ds_sensor.eps
Values shown
in (brackets)
for 3D s sensor
(active area 13 x 13 cm)
(active area 8 x 13 cm)
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