Study on estimation of surface roughness by separation of reflection and backscattering components using ultrasonic synthetic aperture imaging

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 urethane rubber phantoms. The average magnitude of the echo signals from each phantom and the ratio of the mean values of the reflection and scattering components were found to be proportional to the arithmetic average roughness evaluated with a laser surface profilometer. These results show that the proposed separation technique has potentials in evaluation of surface roughness.

Enhancement of reflection and backscattering components by plane wave imaging for estimation of surface roughness

“…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…”

“…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.…”

Determination of thermal and mechanical indices of an ultrasound probe with an inclined beam-axis in accordance with the new JIS (or IEC Standards)

“…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.…”

Investigation on effect of transmit condition on ultrasonic measurement of 2D motion velocity

“…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.…”

“…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.…”