A novel method for the measurement of acoustic speed

Kuo, I.Y.; Hete, B.; Shung, K. K.

doi:10.1121/1.400242

Cited by 91 publications

(44 citation statements)

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“…The plexiglas plate has been chosen as a first-order model for the skull bone because of their similar SOS for both L and T waves (as can be checked in Refs. [10] (plexiglas) and [11] (skull) for L waves). The squama of the investigated temporal bone is less than 2 mm thick and contains probably no spongy bone, making up an "easy" acoustic window.…”

Section: B Water Tank Experimentsmentioning

confidence: 99%

P3B-6 Implications of Mode Conversion on Transcranial Ultrasound Imaging

Vignon

Shi

Yin³

et al. 2007

2007 IEEE Ultrasonics Symposium Proceedings

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Transcranial ultrasound sector images are affected by a "streak artifact": two dark streaks stem radially from the apex to the maximal depth of the scan at particular angles, limiting the effective field of view and diagnostic confidence. The aim of this paper is to investigate experimentally the angle dependency of ultrasound transmission through the skull in order to understand and try to reduce this artifact. It is shown that the streaks are a consequence of the angle-dependent amplitude transmission coefficient at fluid-solid interfaces such as the interfaces between the skull bone and the surrounding fuild-like soft tissues. At a critical incidence angle of about 27°, no ultrasound wave can cross the soft tissue-skull interfaces, which explains the presence of the streaks. At higher incidence angles, mode conversion from longitudinal to transverse waves occurs in the skull, and then back to longitudinal into the brain. The influence of the incidence angle on the distortion of the transmitted beam is also qualitatively assessed. Implications for transcranial imaging are discussed.

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Section: B Water Tank Experimentsmentioning

confidence: 99%

P3B-6 Implications of Mode Conversion on Transcranial Ultrasound Imaging

Vignon

Shi

Yin³

et al. 2007

2007 IEEE Ultrasonics Symposium Proceedings

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“…The speed of sound in the cusp tissue was measured using the method introduced in [7]. For each cusp, the temperature of the CPS was measured with ±0.2 • C accuracy and ±0.1 • C precision using a digital thermometer (Cat.…”

Section: Sound Speed Measurementmentioning

confidence: 99%

Reconsidering the Layer Thickness Distribution in Aortic Valve Cusps Using High-Frequency Ultrasound

Khan

Boughner

Lacefield

2007

2007 4th IEEE International Symposium on Biomedical Imaging: From Nano to Macro

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A non-destructive high-frequency ultrasound method for measuring the thickness of thin tissue layers was adapted to map the thicknesses of the fibrosa, spongiosa, and ventricularis layers of aortic valve cusps. The sound speed and layer thicknesses of thirteen porcine aortic valve cusps were measured. The measurements yielded results of (mean ± standard deviation) 0.81 ± 0.13 mm, 0.30 ± 0.07 mm, 0.23 ± 0.05 mm, and 0.32 ± 0.08 mm for the total, fibrosa, spongiosa, and ventricularis thicknesses, respectively, and a sound speed of 1527 ± 33 m/s. The uncertainty introduced by variations in sound speed plays a relatively small role in the variability of the thickness measurements. The relative distribution of layer thicknesses of fresh, intact cusps measured with this method differs from that of fixed, sliced cusps measured with conventional methods.

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“…Several [7,9,10,20] described a single point ultrasonic velocity measurement method using a reflector plate located behind and separated from the sample, that does not require prior knowledge of sample thickness. The latter, method was studied with success in prototypical scanning configurations for…”

Section: Single Transducer Thickness-independent Ultrasonic Velocity mentioning

confidence: 99%

“…Precision and relative accuracy associated with this method are estimated at near 1 percent for plate-like samples having machined surfaces [17]. The thickness-independent methods noted here [5,[7][8][9][10][16][17]20] require access to both sides of the sample, i.e., there is not a single-sided technique available for scanning that wi11 result in thickness-independence.…”

mentioning

confidence: 99%

A Novel Ultrasonic Method for Accurate Characterization of Microstructural Gradients in Monolithic and Composite Tubular Structures

Roth

Carney

Baaklini

et al. 1999

Review of Progress in Quantitative Nondestructive Evaluation

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Prior studies have shown that ultrasonic velocity/time-of-flight imaging that uses back surface echo reflections to gauge volumetric material quality is well suited (perhaps more so than is the commonlyused peak amplitude c-scanning) for quantitative characterization of microstructural gradients. Such gradients include those due to pore fraction, density, fiber fraction, and chemical composition variations [11][12][13][14][15]. Variations in these microstructural factors can affect the uniformity of physical performance (including mechanical [stiffness, strength], thermal [conductivity], and electrical [conductivity, superconducting transition temperature], etc. performance) of monolithic and composite [1,3,6,12]. A weakness of conventional ultrasonic velocityltime-of-flight imaging (as well as to a lesser extent ultrasonic peak amplitude c-scanning where back surface echoes are gated [17] is that the image shows the effects of thickness as well as microstructural variations unless the part is uniformly thick. This limits this type of imaging's usefulness in practical applications. The effect of thickness is easily observed from the equation for pulse-echo waveform time-of-flight (2'r) between the first front surface echo (FS) and the first back surface echo (B I), or between two successive back surface echoes where:where d is the sample thickness and V is the velocity of ultrasound in the material. Interpretation of the time-of-flight image is difficult as thickness variation effects can mask or overemphasize the true microstructural variation portrayed in the image of a part containing thickness variations. Thickness effects on time-of-flight can also be interpreted by rearranging equation (I) to calculate velocity: (2) such that velocity is inversely proportional to time-of-flight. Velocity and time-of-flight maps will be affected similarly (although inversely in terms of magnitude) by thickness variations, and velocity maps are used in this investigation to indicate time-of-flight variations. SINGLE TRANSDUCER THICKNESS-INDEPENDENT ULTRASONIC VELOCITY MEASUREMENTSSeveral [7,9,10,20] described a single point ultrasonic velocity measurement method using a reflector plate located behind and separated from the sample, that does not require prior knowledge of sample thickness. The latter, method was studied with success in prototypical scanning configurations for

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A novel method for the measurement of acoustic speed

Cited by 91 publications

References 0 publications

P3B-6 Implications of Mode Conversion on Transcranial Ultrasound Imaging

P3B-6 Implications of Mode Conversion on Transcranial Ultrasound Imaging

Reconsidering the Layer Thickness Distribution in Aortic Valve Cusps Using High-Frequency Ultrasound

A Novel Ultrasonic Method for Accurate Characterization of Microstructural Gradients in Monolithic and Composite Tubular Structures

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