A direct method for air kerma-length product measurement in CT for verification of dose display calibrations.
The dose display values of computed tomography (CT) devices are used for patient dose estimation and as a tool for optimisation. Therefore, the dose display value accuracy should be verified. In practice, this means doing measurements in the standard phantoms and comparing results with the dose display values. The traditional method for measuring CT dose enables measurements only for one axial rotation, and there has not been a method for measuring the dose of a complete helical scan sequence. In this work, a new method for a direct measurement of the dose of a complete helical sequence is developed and tested. Results show that this method is practical and that the accuracy of the modern CT devices seems to be at the sufficient level, so that the dose display values can be used for patient dose estimation.
Merimaa
Katja
K
Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki, Finland. katja.merimaa@stuk.fi
Järvinen
Hannu
H
Kortesniemi
Mika
M
Karppinen
Juhani
J
D000465:Algorithms; D001822:Body Burden; D002138:Calibration; D005387:Finland; D006801:Humans; D011829:Radiation Dosage; D011835:Radiation Protection / Q000592:standards*; D011874:Radiometry / Q000592:standards*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000592:standards*