ABSTRACT
La introducción de las adquisiciones helicoidal y multicorte en los equipos de TC y la disminución de los tiempos de reconstrucción de las imágenes han tenido un impacto enorme en la práctica radiológica. El gran desarrollo tecnológico de los últimos 10-12 años ha propiciado la obtención de imágenes de alta calidad en un tiempo muy breve. Con la mejora en la calidad de las imágenes ha aumentado el número de indicaciones. En paralelo con este desarrollo se ha producido un incremento considerable de la exposición a la radiación de los pacientes. La preocupación acerca de los riesgos potenciales para la salud de los exámenes de TC, así como diversas iniciativas y acciones de organismos oficiales y sociedades científicas, constituyen un estímulo para buscar vías de reducción de la exposición a la radiación de los pacientes sin comprometer la eficacia diagnóstica. Con este fin se han establecido recomendaciones de buena práctica, se han desarrollado aplicaciones especiales en los equipos y se han llevado a cabo investigaciones para optimizar el uso clínico de la TC. Entre los desarrollos técnicos incorporados en los equipos cabe destacar los distintos modos de modulación de la intensidad de corriente del tubo, la selección automática de los valores de tensión del tubo, la protección selectiva de órganos, la colimación adaptativa y la reconstrucción iterativa. El uso adecuado de estas herramientas para reducir las dosis precisa de un buen conocimiento sobre su funcionamiento (AU)
The introduction of helical and multislice acquisitions in CT scanners together with decreased image reconstruction times has had a tremendous impact on radiological practice. Technological developments in the last 10 to 12 years have enabled very high quality images to be obtained in a very short time. Improved image quality has led to an increase in the number of indications for CT. In parallel to this development, radiation exposure in patients has increased considerably. Concern about the potential health risks posed by CT imaging, reflected in diverse initiatives and actions by official organs and scientific societies, has prompted the search for ways to reduce radiation exposure in patients without compromising diagnostic efficacy. To this end, good practice guidelines have been established, special applications have been developed for scanners, and research has been undertaken to optimize the clinical use of CT. Noteworthy technical developments incorporated in scanners include the different modes of X -ray tube current modulation, automatic selection of voltage settings, selective organ protection, adaptive collimation, and iterative reconstruction. The appropriate use of these tools to reduce radiation doses requires thorough knowledge of how they work (AU)
Subject(s)
Humans , Radiation Dosage , Tomography, X-Ray Computed/methods , Tomography, X-Ray Computed/trendsABSTRACT
The introduction of helical and multislice acquisitions in CT scanners together with decreased image reconstruction times has had a tremendous impact on radiological practice. Technological developments in the last 10 to 12 years have enabled very high quality images to be obtained in a very short time. Improved image quality has led to an increase in the number of indications for CT. In parallel to this development, radiation exposure in patients has increased considerably. Concern about the potential health risks posed by CT imaging, reflected in diverse initiatives and actions by official organs and scientific societies, has prompted the search for ways to reduce radiation exposure in patients without compromising diagnostic efficacy. To this end, good practice guidelines have been established, special applications have been developed for scanners, and research has been undertaken to optimize the clinical use of CT. Noteworthy technical developments incorporated in scanners include the different modes of X-ray tube current modulation, automatic selection of voltage settings, selective organ protection, adaptive collimation, and iterative reconstruction. The appropriate use of these tools to reduce radiation doses requires thorough knowledge of how they work.
Subject(s)
Radiation Dosage , Tomography, X-Ray Computed/methods , Tomography, X-Ray Computed/trends , HumansABSTRACT
This study aimed at assessment of efficacy of selective in-plane shielding in adults by quantitative evaluation of the achieved dose reduction and image quality. Commercially available accessories for in-plane shielding of the eye lens, thyroid and breast, and an anthropomorphic phantom were used for the evaluation of absorbed dose and image quality. Organ dose and total energy imparted were assessed by means of a Monte Carlo technique taking into account tube voltage, tube current, and scanner type. Image quality was quantified as noise in soft tissue. Application of the lens shield reduced dose to the lens by 27% and to the brain by 1%. The thyroid shield reduced thyroid dose by 26%; the breast shield reduced dose to the breasts by 30% and to the lungs by 15%. Total energy imparted (unshielded/shielded) was 88/86 mJ for computed tomography (CT) brain, 64/60 mJ for CT cervical spine, and 289/260 mJ for CT chest scanning. An increase in image noise could be observed in the ranges were bismuth shielding was applied. The observed reduction of organ dose and total energy imparted could be achieved more efficiently by a reduction of tube current. The application of in-plane selective shielding is therefore discouraged.
