Desenvolvimento de objeto simulador da cabeça para dosimetria em tomografia computadorizada

Abstract

The main goal of this work is the development of an anthropomorphic head phantom for use in computed tomography dosimetry. This phantom was built with materials which are inexpensive and easy to find (alginate and acrylic resin). Additionally, its dosimetric behavior was analyzed in a CT, comparing the values of C100mm and the estimated effective dose. The phantoms were filled with water because of the fact that the mass attenuation coefficients and the mass energy-absorption coefficient indicated that this was the best material to simulate the reference brain (ICRU-44 s brain). Two phantoms were built for this work; one was created using a real skull and the other using a regular mannequin. The phantom created with the real skull showed an average percentage difference of 4% in anatomical measurements in comparison with the reference (ICRU-48). The value of the estimated effective dose in the real skull phantom was 1,29 mSv, a value 5.4 times greater than the computational phantom (MASH). Despite the discrepant value, it represents a 46% improvement in comparison with the geometric PMMA phantom. It is estimated that the cost of the phantom produced from a real skull using the techniques and materials used in this work is approximately R$ 300,00.