Impact of gain on high-frequency contrast-enhanced ultrasound video and radio frequency data

Abstract

We have examined the impact of a gain on contrast-enhanced ultrasound video (JPEG DICOM) and radiofrequency (RF) data. The gain is one of main acquisition parameters and therefore, its influence on a data analysis might be huge. The gain was set in a range of 10 to 50 dB. Imaging was performed with an ultrasound system Vevo 2100 and a linear array probe MS 250 with a transmit frequency of 18 MHz. A contrast agent used in this study was Sonovue (Bracco, Milan, Italy). Measurements were performed for two solutions with a different contrast agent concentration (a dilution factor of 1:4 and 1:16, a solvent is saline). The impact of the gain was evaluated using three parameters: the contrast to background ratio (CBR), the contrast to noise ratio (CNR) and the background to noise ratio (BNR). In RF data, an image intensity grows up continually with the increasing gain but in video data, saturation can occur at higher values of the gain. In terms of the CBR, CNR and BNR, the impact of the gain on RF data is negligible but on video data is substantial.