A preliminary study on an image analysis based method for lowest detectable signal measurements in Pulsed Wave Doppler ultrasounds

Abstract

<span lang="EN-GB">Nowadays, Doppler system performance evaluation is a widespread issue because a shared worldwide standard is still awaited. Among the recommended Doppler test parameters, the lowest detectable signal could be considered mandatory in Quality Control (QC) protocols for Pulsed Wave (PW) Doppler. Such parameter is defined as the minimum signal level that can be clearly distinguished from noise and therefore, it is considered as related to PW Doppler sensitivity. The present study focuses on proposing and validating a novel image analysis based method for the estimation of the Lowest Detectable Signal in the spectrogram image (LDS<sub>IMG</sub>), namely Automatic Doppler Sensitivity Measurement Method (ADSMM), as well as to compare its results with the outcomes retrieved from the Naked Eye Doppler Sensitivity Method (NEDSM), based on the mean judgment of three independent observers. Data have been collected from a Doppler flow phantom, through three ultrasound systems for general purpose imaging, equipped with two linear array probes each and with two configuration settings. Results are globally compatible among the proposed methods, US systems and settings. Further studies could be carried out on a higher number of US diagnostic systems, Doppler frequencies and observers, as well as with different probe and phantom models.</span>

Image quality comparison of two different experimental setups for MEMS actuators functional evaluation: a preliminary study

“…A subjective score is of utmost importance in imaging system quality evaluation, particularly in the case of biomedical imaging systems [18,[21][22][23][24]. In literature comparisons of different methods for subjective images quality assessment have been presented, and among them, the forced-choice pairwise comparison has been found to be the most accurate [25], and besides, it has also been reported as the easiest for observers, as it requires a direct comparison between two images shown simultaneously and only one choice.…”