European Survey of Image Quality Assessment Methods Used in Mammography

Abstract

-The definition of reference dose levels has to be linked with the definition of image quality. Unfortunately, there is still no general agreement on the definition of image quality in mammography, and most of the protocols used are based on the detectability of objects having various shapes and contrasts. To facilitate the task of assessing image quality, scoring methods are often used to produce a single number representative of the imaging chain performance. The goal of this study is to present a comparison between different ways of assessing image quality commonly used in Europe. A set of five mammograms, having different image quality levels, has been obtained with several test objects and compared. The results show large sensitivity variations among the different methods. Concerted work between radiologists and physicists is still required to define the radiological tasks and develop objective ways to measure image quality in mammography.

Survey on image quality and dose levels used in Europe for mammography

“…The test object names were not mentioned to keep the results as anonymous as possible. It is interesting to note that several centres which were in the nonoptimized series because of a lack of resolution used test objects which were more sensitive to noise than resolution [10,19]. Nevertheless, no obvious correlation between the type of test object used in the centres and the position of the centre in the IQI-dose graph appears.…”

“…This study took place during a survey on the different ways used in Europe to assess image quality in mammography [9,10]. During this survey, 24 centres (based in hospitals or private practices) were personally visited by the first author, and information concerning their quality assurance programmes was gathered.…”

Indicadores de calidad en imágenes digitales en programas de control de calidad en mamografía

“…Muchos de los protocolos utilizados para determinarla se basan en la detectabilidad de objetos con varios tamaños y contraste [42]. La forma de determinar la calidad de imagen en este fantoma es valorar la imagen mediante la inspección visual por parte de una persona experta en mamografías.…”

“…En la presente sección se hace una revisión de diferente protocolos que son aplicados actualmente para determinar la calidad de la imagen a partir de distintos tipos de fantomas [42]. Esto, sirvió de base para crear un protocolo para el fantoma utilizado en la presente tesis y que se desarrolla en capitulo cuatro, a partir de los resultados obtenidos tras el procesamiento automático de sus distintas zonas con las técnicas específicamente desarrolladas explicadas en el capítulo siguiente.…”

“…El pequeño tamaño de algunos de los objetos de test y el poco contraste que presentan en la imagen respecto del fondo, hacen que en ocasiones estos objetos no se detecten al analizar la imagen digital [39][40][41][42][43]45]. El análisis de la imagen digital aporta información sobre las características del fantoma que muy difícilmente pueden obtenerse mediante observación directa de la imagen.…”