A comparative study of iAEC (intelligent aperture exposure control) and regular AEC of the mammography system of a major public hospital

Abstract

This research delves into the features offered by the Fujifilm AMULET Innovality Full Field Digital Mammography system. These include the intelligent automatic exposure control features which is claimed to improve patient dose stabilization. The objective of this research was to determine whether this system offers significant or substantial benefit over traditional automatic exposure control systems within the realms of dose, signal-to-noise ratio, and contrast-to-noise ratio. To do so, the DMAM phantom was used. This simulates breast tissues at variable thicknesses and, through the use of a piece of aluminium, is also able to determine the contrast-to-noise ratio of the obtained images. Images were taken at a variety of thicknesses ranging from 20 to 70 mm, with both automatic exposure control and intelligent automatic exposure control. Following this, pixel intensity and standard deviation were measured from the images and used to determine the contrast-to-noise ratio and signal-to-noise ratio. In addition, DICOM tags (0040,8302) and (0040,0316) were used to determine entrance dose and organ dose. Finally, all the data was placed into a dataframe and visualized using the Matplotlib package in Python. It was determined that, overall, images taken with intelligent automatic exposure control systems possessed higher doses, but also a higher signal-to-noise ratio but lower contrast-to-noise ratio for compressions up to approximately 60 mm. The conclusions drawn from this were that the intelligent automatic exposure control system starts to falter at larger thicknesses and, thus, overestimates the dose to be delivered, when compared to standard automatic exposure control systems. Further research should focus on the use of intelligent automatic exposure control on phantoms which possess a lower radiodensity, as well as a comparison between the spatial resolutions of the two systems.