Elastography is based on the estimation of strain due to applied tissue compression. In conventional elastography, computed from gradient displacement estimates between gated pre- and postcompression echo signals. Gradient-based methods are known be susceptible noise. in addition electronic noise, a principal source error decorrelation signal as result compression (decorrelation noise). Temporal stretching signals previously was shown reduce this paper, we introduce novel estimator that uses...

Purpose: This paper describes the design, fabrication, and characterization of multilayered tissue mimicking skin vessel phantoms with tunable mechanical, optical, acoustic properties. The comprise epidermis, dermis, hypodermis layers, blood vessels, fluid. Each component may be individually tailored to a range physiological demographic conditions. Methods: layers were constructed from varying concentrations gelatin agar. Synthetic melanin, India ink, absorbing dyes, Intralipid added provide...

Sonoelasticity is a rapidly evolving medical imaging technique for visualizing hard tumors in tissues. In this novel diagnostic technique, low-frequency vibration externally applied to excite internal vibrations within the tissue under inspection. A small stiff inhomogeneity surrounding appears as disturbance normal eigenmode pattern. By employing properly designed Doppler detection algorithm, real-time image can be made. theory vibrations, or shear wave propagation inhomogeneous has been...

Tissue motion and elasticity imaging techniques commonly use time delay estimation (TDE) for the assessment of tissue displacement. The performance these is limited because signals are corrupted by various factors including electronic noise, quantization, speckle decorrelation. Speckle decorrelation caused changes in coherent interference among scatterers when moves relative to ultrasound beam. In estimation, effect noise usually addressed through signal-to-noise ratio (SNR) term....

PURPOSE: To compare sonoelasticity imaging versus ultrasound (US) in detection of prostate cancer. MATERIALS AND METHODS: Sonoelasticity and US were performed on 10 prostatectomy specimens which cancer was detected at previous biopsy. Six patients had no palpable lesions digital rectal examination. Specimens imaged axially the apex, middle, base gland to correlate with location pathologic sections. All images interpreted blindly prospectively, results compared findings. RESULTS: Sensitivity...

Conventional techniques in elastography estimate strain as the gradient of displacement estimates obtained through crosscorrelation pre- and postcompression rf A-lines. In these techniques, displacements are estimated over overlapping windows strains adjacent windows. The large amount noise at high window overlaps may result poor quality elastograms, thus restricting applicability conventional estimation to low overlaps, which, turn, results a small number pixels image. To overcome this...

We have developed quantitative descriptors to provide an objective means of noninvasive identification cancerous breast lesions. These include acoustic features assessed using spectrum analysis ultrasonic radiofrequency (rf) echo signals and morphometric properties related lesion shape. Acoustic measures echogenicity, heterogeneity shadowing, computed by generating spectral-parameter images the surrounding tissue. Spectral-parameter values are derived from rf at each pixel a sliding-window...

When a breast lump is detected through palpation, mammography or ultrasonography, the final test for characterization of tumour, whether it malignant benign, biopsy. This invasive and carries hazards associated with any surgical procedures. The present work was undertaken to study feasibility such using non-invasive electrical impedance measurements machine learning techniques. Because changes in cell morphology benign tumours, are expected at fixed frequency, versus frequency measurement....

We present a novel, robust and accurate blood velocity estimation technique that is implementable by elementary digital signal processing.In this technique, echoes from repeated firings of transducer are resampled along set predetermined trajectories constant velocities, called "butterlly lines" because their intersection at reference range.The slope the trajectory on which sampled signals satisfy criterion appropriate for type in question, provides an estimate target.The search "butterfly...

We evaluate texture quantified from ultrasound Nakagami parametric images for non-invasive characterization of breast tumors, as can more faithfully represent intrinsic tumor characteristics than standard B-mode images.Parametric were formed using sliding windows applied to envelope data. To analyze the trade-off between spatial resolution and stability estimated parameters quantification, two different window sizes used image formation: (i) square with sides equal three times pulse length...

We present a novel method for estimating the mean scatterer spacing (MSS) of breast tumors using ensemble empirical mode decomposition (EEMD) domain analysis deconvolved backscattered radio frequency (RF) data. The autoregressive (AR) spectrum from which MSS is estimated obtained intrinsic functions (IMFs) due to regular scatterers embedded in RF data corrupted by diffuse scatterers. IMFs are chosen giving priority presence an enhanced fundamental harmonic and greater number higher harmonics...

In conventional elastography, internal tissue deformations, induced by external compression applied to the surface, are estimated cross-correlation analysis of echo signals obtained before and after compression. Conventionally, strains computing gradient displacement. However, gradient-based algorithms highly susceptible noise decorrelation, which could limit their utility. We previously developed strain estimators based on a frequency-domain (spectral) formulation that were shown be more...