Abstract:The luminal surface of the arterial wall roughens in the early-stage atherosclerosis. A possible differentiation between the reflected and scattered components in the ultrasonic echo from the arterial wall potentially can serve as a diagnostic tool when such roughening occurs. This study presents a method for the differentiation of reflection and scattering components by creating ultrasonic beams from different directions using the synthetic aperture method. The technique was evaluated in experiments on uretha… Show more
“…The measurements were performed at five different positions. 28) The average of the arithmetic average roughnesses was used as an index of surface roughness. SG1025-5…”
Section: Arithmetic Average Roughness Measurement Experimentmentioning
confidence: 99%
“…27) In addition, the coefficient of variation calculated by the standard deviation of the backscattered component and the mean value of the reflected component was correlated with the roughness in the experiment conducted using phantoms. 28) On the other hand, this method requires a number of transmit-receive events to generate a Bmode image, and it would be preferable to acquire a full dataset with a few transmit-receive events for a moving target like an arterial wall. We investigated the feasibility of plane wave imaging in separation of reflection and backscattering components by phantom experiments.…”
In the early stage of atherosclerosis, the luminal surface of the arterial wall becomes rough. Methods for distinguishing between the reflected and backscattered components in the ultrasonic echo from the arterial wall has the potential to be used as a method for assessment of the roughness of the arterial wall. In this study, we proposed a method to distinguish between the reflected and backscattered components using a technique based on plane wave compounding. This method was evaluated by experiments using planar phantoms with rough surfaces made of polyurethane rubber. The coefficient of variation calculated from the mean value of the reflection component and the standard deviation of the backscattering component was proportional to the roughness of the rubber phantom. This result shows the potential usefulness of this method for analyzing surface roughness of the arterial wall.
“…The measurements were performed at five different positions. 28) The average of the arithmetic average roughnesses was used as an index of surface roughness. SG1025-5…”
Section: Arithmetic Average Roughness Measurement Experimentmentioning
confidence: 99%
“…27) In addition, the coefficient of variation calculated by the standard deviation of the backscattered component and the mean value of the reflected component was correlated with the roughness in the experiment conducted using phantoms. 28) On the other hand, this method requires a number of transmit-receive events to generate a Bmode image, and it would be preferable to acquire a full dataset with a few transmit-receive events for a moving target like an arterial wall. We investigated the feasibility of plane wave imaging in separation of reflection and backscattering components by phantom experiments.…”
In the early stage of atherosclerosis, the luminal surface of the arterial wall becomes rough. Methods for distinguishing between the reflected and backscattered components in the ultrasonic echo from the arterial wall has the potential to be used as a method for assessment of the roughness of the arterial wall. In this study, we proposed a method to distinguish between the reflected and backscattered components using a technique based on plane wave compounding. This method was evaluated by experiments using planar phantoms with rough surfaces made of polyurethane rubber. The coefficient of variation calculated from the mean value of the reflection component and the standard deviation of the backscattering component was proportional to the roughness of the rubber phantom. This result shows the potential usefulness of this method for analyzing surface roughness of the arterial wall.
“…Research on ultrasonic diagnosis [1][2][3][4][5][6][7][8][9][10][11][12][13] and ultrasonic therapy 14,15) are important in developing safe and highperformance medical ultrasonic equipment. As for ultrasonic diagnostic equipment, precise and practical test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields are required to ensure the safety of patients in diagnosis.…”
It is necessary to measure the bounded-square output power (P1x1) for determination of soft tissue thermal index (TIS) for both scanning and non-scanning modes of an ultrasonic diagnostic equipment according to the new JIS (or IEC Standards). However, there is no report about how to measure P1x1 for an ultrasound probe with an inclined beam-axis (UPIB). We designed an angle-corrected 1 cm × 1 cm absorbing mask in accordance with the spirit of the IEC 62359 Ed.2.0 and established a reasonable process for measurement of TIS and MI of a paste type probe (PTP), which is a specially designed UPIB for examination of the blood flow in carotid artery more conveniently and efficiently. Both TIS and MI of the PTP were much less than 1.0 at all selectable presetting of the blood flow monitor, FURUHATA device, suggesting it’s as safe as a common ultrasonic Doppler diagnostic device.
“…13) High frame rate ultrasound is highly beneficial for measurement of tissue dynamics and has been widely studied to achieve high temporal and spatial resolution simultaneously. [19][20][21][22][23][24][25][26] We conducted a preliminary study on investigation of the effect of conditions for emission of ultrasonic waves on the accuracy of the phase-sensitive 2D motion estimator. 27) However, only two transmission methods, i.e.…”
Section: Introductionmentioning
confidence: 99%
“…SAI was developed in the field of radar systems and introduced to the field of medical ultrasonic imaging to obtain a high-resolution image at a high frame rate. 22,23) In the present study, spherical waves were emitted from a transmit aperture composed of 64 elements, and ultrasonic echoes were received with all elements in the probe. In the present study, the active transmit aperture was shifted by 6 elements after every transmission, and the transmit-receive event was repeated 21 times.…”
A phase-sensitive 2D motion estimator is useful for measurement of minute tissue motion. However, the effect of conditions for emission of ultrasonic waves on the accuracy of such an estimator has not been investigated thoroughly. In the present study, the accuracy of the phase-sensitive 2D motion estimator was evaluated under a variety of transmission conditions. Although plane wave imaging with a single emission per frame achieved an extremely high temporal resolution of 10417 Hz, the accuracy in estimation of lateral velocities was worse than compound-based method or focused-beam method. By contrast, the accuracy in estimation of axial velocities hardly depended on the transmission conditions. Also, the phase-sensitive 2D motion estimator was combined with the block matching method to estimate displacements larger than the ultrasonic wavelength. Furthermore, the results show that the correlation coefficient in block matching has potential to be used for evaluation of the reliability of the estimated velocity.
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