The impact of field size and radiation quality on KAP-meter and CT-chamber response
AuthorsŽivanović, Miloš Z.
Lazarević, Đorđe R.
Article (Published version)
MetadataShow full item record
Kerma-area product and kerma-length product are important practical dosimetric quantities used in diagnostic radiology. These quantities are measured by special types of dosimeters which are calibrated in standard radiation qualities established in calibration laboratories. However, in clinical practice the dosimeters are used in different conditions, including the radiation quality and field size. In this paper, energy and field size dependence are studied for both types of dosimeters. One dosimeter of each type is tested. The KAP-meter has shown significant dependence on both radiation quality and field size, while the dependence of the CT-chamber is much less pronounced. Two different approaches can be used to correct for the difference between conditions during calibration and in clinical practice. When the clinical beam is well characterized and energy and field size dependence of the dosimeter are well known, the optimum solution is to apply the adequate correction factor to the ...measurements, keeping measurement uncertainty as low as possible. If this is not the case, the above limitations must be taken under consideration in the calculation of the expanded uncertainty budget.
Keywords:calibration / diagnostic radiology / dosimetry / energy response / field size / kerma-area product / kerma-length product / metrology
Source:Nuclear Technology and Radiation Protection, 2018, 33, 1, 87-92
- International Atomic Energy Agency (IAEA) (SRB/6/012)