Modelagem e simulação de filme radiográfico através de programação paralela e distribuída orientada a objetos

Abstract

Analog X-ray films still have relevance in various applications, both in the medical and industrial fields. The behavior of an X-ray film and its characteristics when exposed to X-rays can be studied through the analysis of the sensitometric curve. In this regard, the use of computer simulations becomes a valuable tool for saving time and resources in analyzing the film’s performance under different settings. Despite the advantages, simulations involving a large number of random events require techniques such as Monte Carlo, which, although robust, can be quite slow, often requiring parallelization, as is the case with simulating the sensitization process in a discrete X-ray film. This work presents a computational tool capable of simulating analog X-ray films. More specifically, it simulates the emulsion layer containing silver halide crystals, which are represented by bits in the pixels of a discretized film. The simulator provides a map containing the number of sensitized grains per pixel. Sensitometric curves were obtained using the data provided by the simulator and compared with theoretical curves to validate the proposed model. For the construction of this tool, the Charm++ programming language was used on a cluster consisting of six high-performance computers. The sensitometric curves are generated from sequences of simulated X-ray images with different energy and fluence characteristics, and compared with corresponding theoretical curves. Deductions for the formal and logical modeling of X-ray films in monochromatic and polychromatic beams are presented, taking into account a vacuum system. Relevant alterations to the equations used to consider attenuation due to the presence of dry air and the lucite step wedge are also indicated. The generated characteristic curves allow verifying that the simulated results coincide with the theoretical ones, thus validating the modeling of an X-ray film. Within the limits of the presented modeling, it is considered that the tool is suitable for characterizing X-ray films, as well as for professional training and predicting the behavior of related systems. Furthermore, it is expected that this modeling can open up new possibilities for simulation applications.