Otimização de exames de extremidade para radiologia computadorizada

• Main Author: Pavan, Ana Luiza Menegatti [UNESP]
• Publication Date: 2013
• Other Authors: Pina, Diana Rodrigues de [UNESP], Alves, Allan Felipe Fattori [UNESP], Velo, Alexandre França [UNESP], Miranda, José Ricardo de Arruda [UNESP]
• Format: Article
• Language: por
• Source: Repositório Institucional da UNESP
• Download full: http://www.rbfm.org.br/index.php/rbfm/article/view/245; http://hdl.handle.net/11449/140821
• topic: Simulation; Dosimetry; Radiology; Upper extremity; Simulação; Dosimetria; Radiologia; Extremidade superior

The computed radiography (CR) has become the most used device for image acquisition, since its introduction in the 80s. The detection and early diagnosis, obtained through CR examinations, are important for the successful treatment of diseases of the hand. However, the norms used for optimization of these images are based on international protocols. Therefore, it is necessary to determine letters of radiographic techniques for CR system, which provides a safe medical diagnosis, with doses as low as reasonably achievables. The objective of this work is to develop an extremity homogeneous phantom to be used in the calibration process of radiographic techniques. In the construction process of the simulator, it has been developed a tissues’ algorithm quantifier using Matlab®. In this process the average thickness was quantified from bone and soft tissues in the region of the hand of an anthropomorphic simulator as well as the simulators’ material thickness corresponding (aluminum and Lucite) using technique of mask application and removal Gaussian histogram corresponding to tissues of interest. The homogeneous phantom was used to calibrate the x-ray beam. The techniques were implemented in a calibrated hand anthropomorphic phantom. The images were evaluated by specialists in radiology by the method of VGA. Skin entrance surface doses were estimated (SED) corresponding to each technique obtained with their respective tube charge. The thicknesses of simulators materials that constitute the homogeneous phantom determined in this study were 19.01 mm of acrylic and 0.81 mm of aluminum. A better picture quality with doses as low as reasonably achievable decreased dose and tube charge around 53.35% and 37.78% respectively, compared normally used by radiology diagnostic routine clinical of HCFMB-UNESP.