Quantification of hand tissues to dose optimization procedures in computed radiology

Abstract

This study presents the development of a homog-enous hand patient equivalent phantom (hPEP) to be used in an optimization process in computed radiography systems. Lucite and aluminum plates were used for hPEP construction and their thickness were determined by the equivalence of tissues from anthropomorphic phantom (2.5 cm and 0.2 cm respectively). This phantom was used in x-ray beam calibra-tion to obtain the test-techniques of the optimization process with Agfa® exposure index values between 1.8 and 2.0. These test-techniques were applied to an anthropomorphic phantom to the image quality optimization process. In this process the obtained images were assessed by three experienced radiolo-gists through visual grading analysis, and a gold standard (GS) technique was selected on the basis of image quality and As Low As Reasonable Achievable (ALARA) dose. Compared to the previously adopted technique for the clinical routine of the HCFMB-UNESP, the GS technique provided optimal image quality, with reductions in dose and tube load of 41.3% and 33.2%, respectively. The images generated by using GS tech-nique has satisfactory quality for a safe diagnosis, decreasing the radiation risk to the patient and increasing the lifetime of the x-ray tube.