The unique radiation exposure conditions that exist in computed tomography (CT), during which thin slices of the patient are irradiated by a narrow, fan-shaped beam of x rays emitted from the x-ray tube during its rotation around the patient, have required the use of special dosimetry techniques to characterize the radiation doses to patients and to monitor CT system performance. This section d...

The possibility of using Brazilian stones in gamma high-dose dosimetry was investigated at IPEN using the optically stimulated luminescence (OSL) technique. Agate samples were studied in relation to their OSL dosimetric properties, in this work. The samples were irradiated at a Gamma-Cell system (Co). The calibration curves show a sublinear behavior between 50 Gy and 300 kGy, and the lower dete...

Dosimetry is the science of measuring radiation dosage. The absorbed dose of radiation is measured in a unit called “gray” (Gy). Radiation dosage measurements and ensuring they are as accurate as possible are important if the benefits of the application of nuclear technology in health care are to be harnessed. Radioactive processes and radiation are utilized in many health related technologies,...

The applications of mathematical simulations of tissue tem perature distributions in hyperthermia treatments are discussed in terms of four areas, comparative, prospective, concurrent, and retrospective thermal dosimetry. These four aspects of thermal dosimetry cover the range of hyperthermia applications of interest to clinicians, from comparative evaluation of compet itive heating modalities ...

The problem of choosing a prior distribution for the Bayesian interpretation of measurements (specifically internal dosimetry measurements) is considered using a theoretical analysis and by examining historical tritium and plutonium urine bioassay data from Los Alamos. Two models for the prior probability distribution are proposed: (1) the log-normal distribution, when there is some additional ...

Gafchromic XRCT radiochromic film is a self-developing high sensitivity radiochromic film product which can be used for assessment of delivered radiation doses which could match applications such as computed tomography (CT) dosimetry. The film automatically changes colour upon irradiation changing from a yellow to green/brown colour. The absorption spectra of Gafchromic XRCT radiochromic film a...

A lack of suitable dosimetric quantities for application in diagnostic radiology is noted by Dr Moores. It is concluded by Dr Moores that it is not possible to adhere to the basic principles of the International Commission on Radiation Units and Measurements (ICRU) regarding patient dosimetry in diagnostic radiology due to the extremely wide variety of quantities and units employed. The conclus...