Dataset Information

Time domain attenuation estimation method from ultrasonic backscattered signals.

ABSTRACT: Ultrasonic attenuation is important not only as a parameter for characterizing tissue but also for compensating other parameters that are used to classify tissues. Several techniques have been explored for estimating ultrasonic attenuation from backscattered signals. In the present study, a technique is developed to estimate the local ultrasonic attenuation coefficient by analyzing the time domain backscattered signal. The proposed method incorporates an objective function that combines the diffraction pattern of the source/receiver with the attenuation slope in an integral equation. The technique was assessed through simulations and validated through experiments with a tissue mimicking phantom and fresh rabbit liver samples. The attenuation values estimated using the proposed technique were compared with the attenuation estimated using insertion loss measurements. For a data block size of 15 pulse lengths axially and 15 beamwidths laterally, the mean attenuation estimates from the tissue mimicking phantoms were within 10% of the estimates using insertion loss measurements. With a data block size of 20 pulse lengths axially and 20 beamwidths laterally, the error in the attenuation values estimated from the liver samples were within 10% of the attenuation values estimated from the insertion loss measurements.

SUBMITTER: Ghoshal G

PROVIDER: S-EPMC3407163 | biostudies-other | 2012 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BackgroundAn important indicator of penile erectile function is erection hardness (EH), which is currently evaluated by the semi-quantitative erectile hardness score (EHS). EH increases continuously during the course of an erection, so although it is statistically a continuous variable, the EHS is a grade variable. We propose a new method for real-time quantitative measurement of penile EH using ultrasonic shear wave elastography (SWE).MethodsThe study group comprised 40 patients with erectile dysfunction (ED) and 20 normal controls who all underwent real-time SWE to measure tissue stiffness (Young's modulus, YM) of the penile corpus cavernosum and tunica albuginea during erection, at rest and at different EH grades induced by intracavernosal injection (ICI) of prostaglandin. The examiner gently placed the high frequency probe on the ventral penis and got the two-dimensional longitudinal US image of penis, then switched to SWE mode, the appropriate region of interest (ROI) was selected, then a 3-5 mm circle ("Q-box") was automatically set to by machine to measure the SWE of the corpus cavernosum and tunica albuginea on the left side.ResultsIn both the ED patients and normal controls, YM slightly decreased in the corpus cavernosum during erection but the stiffness of tunica albuginea increased significantly with increasing EH (resting: 21.66±4.21 kPa, grades 1-4: 32.61±4.27, 54.86±8.69, 128.02±20.66, and 223.23±23.61 kPa, respectively). Because EH grades 1 and 2 clinically predicted failure to complete sexual intercourse, and EH grades 3 and 4 predicted ability, the cutoff point for the YM of the tunica albuginea to evaluate whether sexual intercourse could be completed was 81.60 kPa.ConclusionsOur data demonstrated that tunica albuginea stiffness, not corpus cavernosum stiffness, provided a good clinical imaging index indicator for evaluating penile EH. The tunica albuginea stiffness changed continuously during penile erection, which could be measured quantitatively by SWE. Compared with the EHS, measuring the YM of the penile tunica albuginea using SWE is a new and objective technique for quantitatively assessing EH. Because of its objective and quantifiable characteristics, measuring YM enables more accurate evaluation of the effect on EH of various treatments for ED.

Dataset Information

Time domain attenuation estimation method from ultrasonic backscattered signals.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets