(a) Cylindrical PMMA phantoms of 20 and 32 mm diameter and (b) dosimetric equipment (phantom, ionization chamber, TLD holder, and TLD rods) used for dose measurements.
Example for the TLD placement in the 2 mice cadavers (maximum intensity projections of mouse two, first scan). Three sets of two TLDs each were placed at different positions in the mouse cadaver: One in the abdomen and two in the thorax [anatomical right (r) and left (l)].
Calibration results: ionization chamber response over the voltage range typical for (a) the TomoScope micro-CT scanner (40, 50, and 60 kV) and (b) clinical CT (beam qualities RQR 9, RQA 9, RQT 8–10, see Table IV).
CTDI100 measured free in air and in the central cavity of the 20 and 32 mm cylindrical PMMA phantoms in a six month interval between June and December 2010.
Spectra calculated according to Tucker et al. as well as measured spectra (40 and 60 kV).
CTDI100,c as a function of voltage for both cylindrical PMMA phantoms using (a) spectra calculated according to Tucker et al. and (b) spectra measured at our institute.
Dose profiles along the z-axis measured with TLD rods (points) and calculated using MC calculations (lines) for three different voltages and the 32 mm PMMA phantom.
(a) Measured versus calculated CT values at 40 kV for all materials listen in Table III. (b) Density vs CT value for different human tissues at 40 kV.
(a) Slice through an acquired CT dataset of a mouse and (b) corresponding dose distribution.
Approach of CTDI L to the equilibrium dose for the 32 mm phantom and a tube voltage of 60 kV.
Technical parameters of the TomoScope micro-CT scanner.
Tube voltage, total tube output, and air kerma for all scan protocols used.
Materials used for stoichiometric calibration of the MC tool.
Beam qualities for clinical CT [according to IEC 51267:2005 (Ref. 28)].
Materials and corresponding CT value thresholds used for material decomposition at 40 kV.
Measured and calculated TLD readings, calibrated in air kerma at different positions (r = anatomical right, l = anatomical left) in two mice cadavers.
Article metrics loading...
Full text loading...