Songklanakarin Journal of Science and Technology (SJST) (Dec 2012)
Performance analysis of linear bandpass filter and pulse inversion in separating subharmonic frequency of signals from ultrasound contrast agent
Abstract
Recently, many publications reported the generation of subharmonic frequency (f0/2) and its potential use in imagingfrom ultrasound contrast agent (UCA). Subharmonic imaging (SHI) has provided better contrast resolution over the secondharmonic signals due to the lack of subharmonic generation in the tissue region. However, subharmonic separation in SHIutilizes linear bandpass filtering only. In this paper, we compare the subharmonic separation capability of linear band filter(LBF), pulse inversion (PI), and their combination (PILBF) based on contrast-to-tissue ratio (CTR). Results show that theCTR values from the LBF, the PI, and the PILBF are 20.30, 40.30, and 52.74 dB, respectively. The optimal stopband attenuation and fractional bandwidth for the PILBF method are 50 dB and 10%, respectively. This high CTR value indicates thefeasibility of the PILBF method in creating high quality ultrasound image from subharmonic frequency.
