RESUMO
The purpose of this study is to evaluate the accuracy of automatic matching in cone-beam computed tomography (CBCT) images relative to the reduction of total tube current-exposure time product (mAs) for the X-ray imaging (XI) system. The CBCT images were acquired with the Catphan 504 phantom various total mAs ratios such as 1.00, 0.83, 0.67, 0.57, and 0.50. For studying the automatic match-ing accuracy, the phantom images were acquired with a six-dimensional shifting table. The image quality and correction of automatic matching were compared. With a decreasing total mAs ratio, the noise of the images increased and the low-contrast resolution decreased, while the accuracy of the automatic matching did not change. Therefore, this study shows that a change of the total mAs while acquiring CBCT images has no effect on the automatic matching of Catphan 504 phantom in XI system.
Assuntos
Algoritmos , Tomografia Computadorizada de Feixe Cônico/métodos , Processamento de Imagem Assistida por Computador/métodos , Imagens de Fantasmas , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Automação , Desenho de Equipamento , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Espalhamento de Radiação , Raios XRESUMO
Hantaviruses cause two forms of human disease: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome. Hantavirus infection can occur in pregnant women and it can have an influence on the maternal and fetal outcomes, although this is a rare finding even in endemic areas. We describe here a recent case of HFRS complicating pregnancy.