phantom and MOSFET dosimeters
The following is an example of an empirical method that was used to measure dose from CT examinations in a paediatric phantom. In this example 4 banks of 5 dosimeters were utilised. Figure 13 illustrates a paediatric phantom with the MOSFET dosimeters located in specific organs and tissues. With only 20 dosimeters available the phantom is loaded and
Figure (13) Loading the phantom with MOSFET detectors and scan set up.
irradiated in order, locations 1-20, then 21-40 and so on. The obtained values (mV/mGy) are sent to the computer via wireless network and saved as an Excel file sheet. This was then repeated many times until all of the 167 or 271 dose locations had mV readings for
paediatric and adult ATOM phantoms, respectively. Once the data is gathered they are divided by the respective calibration factors (Table 11) for each MOSFET dosimeter in order to determine organ and tissues absorbed dose.
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