TY - GEN
T1 - Design of quadratic filters for contrast-assisted ultrasonic imaging
AU - Phukpattaranont, Pornchai
AU - Nilmanee, Tojsaporn
AU - Limsakul, Chusak
AU - Ebbini, Emad S
PY - 2007/12/1
Y1 - 2007/12/1
N2 - We present a novel design of a quadratic filter (QF) in order to improve the quality of contrast-assisted ultrasound images for medical diagnosis. The design of QFs for capturing the second order nonlinearities is performed in frequency domain. The two-dimensional (2D) frequency response of the optimum quadratic filter is composed of two 2D Gaussian functions with different spreads in their major and minor axes. The centers of the Gaussian functions are positioned at frequency pairs where the contrast-to-tissue (CTR) ratio is maximal along the main diagonal of 2D frequency plane. Subsequently, the bandwidth of filter is independently determined to optimize spatial resolution. Therefore, the new design approach offers two degrees of freedom in maximizing the CTR and spatial resolution simultaneously. This avoids the inherent tradeoff between contrast and spatial resolution when linear filters are used (e.g. in second harmonic imaging). We demonstrate the performance of the new approach with echo data from a flow phantom.
AB - We present a novel design of a quadratic filter (QF) in order to improve the quality of contrast-assisted ultrasound images for medical diagnosis. The design of QFs for capturing the second order nonlinearities is performed in frequency domain. The two-dimensional (2D) frequency response of the optimum quadratic filter is composed of two 2D Gaussian functions with different spreads in their major and minor axes. The centers of the Gaussian functions are positioned at frequency pairs where the contrast-to-tissue (CTR) ratio is maximal along the main diagonal of 2D frequency plane. Subsequently, the bandwidth of filter is independently determined to optimize spatial resolution. Therefore, the new design approach offers two degrees of freedom in maximizing the CTR and spatial resolution simultaneously. This avoids the inherent tradeoff between contrast and spatial resolution when linear filters are used (e.g. in second harmonic imaging). We demonstrate the performance of the new approach with echo data from a flow phantom.
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U2 - 10.1109/ULTSYM.2007.556
DO - 10.1109/ULTSYM.2007.556
M3 - Conference contribution
AN - SCOPUS:48149088584
SN - 1424413834
SN - 9781424413836
T3 - Proceedings - IEEE Ultrasonics Symposium
SP - 2211
EP - 2214
BT - 2007 IEEE Ultrasonics Symposium Proceedings, IUS
T2 - 2007 IEEE Ultrasonics Symposium, IUS
Y2 - 28 October 2007 through 31 October 2007
ER -