A theoretical framework for performance characterization of elastography: the strain filter

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control ferroelectrics, and frequency control, 1997-01, Vol.44 (1), p.164-172
• Main Authors: Varghese, T., Ophir, J.
• Format: Article
• Language: English
• Subjects: Acoustical measurements and instrumentation; Acoustics; Biological and medical sciences; Capacitive sensors; Decorrelation; Dynamic range; Exact sciences and technology; Filtering; Filters; Fundamental areas of phenomenology (including applications); Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Miscellaneous. Technology; Physics; Quantization; Signal sampling; Signal to noise ratio; Ultrasonic imaging; Ultrasonic investigative techniques; Upper bound
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/58.585212

This paper presents a theoretical framework for performance characterization in strain estimation, which includes the effect of signal decorrelation, quantization errors due to the finite temporal sampling rate, and electronic noise. An upper bound on the performance of the strain estimator in elastography is obtained from a strain filter constructed using these limits. The strain filter is a term used to describe the nonlinear filtering process in the strain domain (due to the ultrasound system and signal processing parameters) that allows the elastographic depiction of a limited range of strains from the compressed tissue. The strain filter predicts the elastogram quality by specifying the elastographic signal-to-noise ratio (SNR/sub e/), sensitivity, and the strain dynamic range at a given resolution. The dynamic range is limited by decorrelation errors for large tissue strain values, and electronic noise for low strain values. Tradeoffs between different techniques used to enhance elastogram image quality may also be analyzed using the strain filter.