Estimation method for sound velocity distribution for high-resolution ultrasonic tomographic imaging

Abe, Keiichiro; Arakawa, Mototaka; Kanai, Hiroshi

doi:10.1007/s10396-018-0915-9

Cited by 19 publications

(18 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their approach solves the above‐stated issue of hydrophone positioning‐derived error, by co‐registering the BP and the underlying anatomy images. In addition, array transducers may be used to estimate the in vivo sound speed for the liver 36 and breast, 37 increasing the accuracy of in vivo range verification. Methods that utilize multiple hydrophones simultaneously to reconstruct the dose distribution were also explored in simulation study, using 3D filtered backprojection, 38 time reversal algorithms, 39 and dictionary method 40 .…”

Section: Discussionmentioning

confidence: 99%

“…Their approach solves the above-stated issue of hydrophone positioning-derived error, by co-registering the BP and the underlying anatomy images. In addition, array transducers may be used to estimate the in vivo sound speed for the liver 36 and breast, 37 increasing the accuracy of in vivo range verification. Methods that The maximum pressure amplitude of about 23 mV (Figure 1 in Ref.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Technical Note: Range verification of pulsed proton beams from fixed‐field alternating gradient accelerator by means of time‐of‐flight measurement of ionoacoustic waves

et al. 2021

View full text Add to dashboard Cite

Purpose Ionoacoustics is one of the promising approaches to verify the beam range in proton therapy. However, the weakness of the wave signal remains a main hindrance to its application in clinics. Here we studied the potential use of a fixed‐field alternating gradient accelerator (FFA), one of the accelerator candidates for future proton therapy. For such end, magnitude of the pressure wave and range accuracy achieved by the short‐pulsed beam of FFA were assessed, using both simulation and experimental procedure. Methods A 100 MeV proton beam from the FFA was applied on a water phantom, through the acrylic wall. The beam range measured by the Bragg peak (BP)‐ionization chamber (BPC) was 77.6 mm, while the maximum dose at BP was estimated to be 0.35 Gy/pulse. A hydrophone was placed 20 mm downstream of the BP, and signals were amplified and stored by a digital oscilloscope, averaged, and low‐pass filtered. Time‐of‐flight (TOF) and two relative TOF values were analyzed in order to determine the beam range. Furthermore, an acoustic wave transport simulation was conducted to estimate the amplitude of the pressure waves. Results The range calculated when using two relative TOF was 78.16 ± 0.01 and 78.14 ± 0.01 mm, respectively, both values being coherent with the range measured by the BPC (the difference was 0.5‒0.6 mm). In contrast, utilizing the direct TOF resulted in a range error of 1.8 mm. Fivefold and 50‐fold averaging were required to suppress the range variation to below 1 mm for TOF and relative TOF measures, respectively. The simulation suggested the magnitude of pressure wave at the detector exceeded 7 Pascal. Conclusion A submillimeter range accuracy was attained with a pulsed beam of about 21 ns from an FFA, at a clinical energy using relative TOF. To precisely quantify the range with a single TOF measurement, subsequent improvement in the measuring system is required.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Technical Note: Range verification of pulsed proton beams from fixed‐field alternating gradient accelerator by means of time‐of‐flight measurement of ionoacoustic waves

et al. 2021

View full text Add to dashboard Cite

show abstract

“…However, there are restrictions on the conditions for setting the propagation route between the evaluation target and each element of the probe, and the estimation accuracy of the local speed of sound can be low. Methods for solving this problem include the technologies proposed by Jakovljevic et al [ 26 ] and Abe and Kanai et al [ 27 ].…”

Section: Speed Of Sound Evaluationmentioning

confidence: 99%

Basic concept and clinical applications of quantitative ultrasound (QUS) technologies

Yamaguchi

2021

J Med Ultrasonics

View full text Add to dashboard Cite

In the field of clinical ultrasound, the full digitalization of diagnostic equipment in the 2000s enabled the technological development of quantitative ultrasound (QUS), followed by multiple diagnostic technologies that have been put into practical use in recent years. In QUS, tissue characteristics are quantified and parameters are calculated by analyzing the radiofrequency (RF) echo signals returning to the transducer. However, the physical properties (and pathological level structure) of the biological tissues responsible for the imaging features and QUS parameters have not been sufficiently verified as there are various conditions for observing living tissue with ultrasound and inevitable discrepancies between theoretical and actual measurements. A major issue of QUS in clinical application is that the evaluation results depend on the acquisition conditions of the RF echo signal as the source of the image information, and also vary according to the model of the diagnostic device. In this paper, typical examples of QUS techniques for evaluating attenuation, speed of sound, amplitude envelope characteristics, and backscatter coefficient in living tissues are introduced. Exemplary basic research and clinical applications related to these technologies, and initiatives currently being undertaken to establish the QUS method as a true tissue characterization technology, are also discussed.

show abstract

“…The arrival time of an ultrasonic echo was estimated from the temporal position of the pulse or correlation analysis applied to echo obtained from two directions. The sound speed was also estimated using the delay profile of an echo from a distinct scatterer [ 73 ].…”

Section: Recent Trends In Adaptive Imagingmentioning

confidence: 99%

Advances in ultrasonography: image formation and quality assessment

Hasegawa

2021

J Med Ultrasonics

View full text Add to dashboard Cite

Delay-and-sum (DAS) beamforming is widely used for generation of B-mode images from echo signals obtained with an array probe composed of transducer elements. However, the resolution and contrast achieved with DAS beamforming are determined by the physical specifications of the array, e.g., size and pitch of elements. To overcome this limitation, adaptive imaging methods have recently been explored extensively thanks to the dissemination of digital and programmable ultrasound systems. On the other hand, it is also important to evaluate the performance of such adaptive imaging methods quantitatively to validate whether the modification of the image characteristics resulting from the developed method is appropriate. Since many adaptive imaging methods have been developed and they often alter image characteristics, attempts have also been made to update the methods for quantitative assessment of image quality. This article provides a review of recent developments in adaptive imaging and image quality assessment.

show abstract

Estimation method for sound velocity distribution for high-resolution ultrasonic tomographic imaging

Cited by 19 publications

References 23 publications

Technical Note: Range verification of pulsed proton beams from fixed‐field alternating gradient accelerator by means of time‐of‐flight measurement of ionoacoustic waves

Technical Note: Range verification of pulsed proton beams from fixed‐field alternating gradient accelerator by means of time‐of‐flight measurement of ionoacoustic waves

Basic concept and clinical applications of quantitative ultrasound (QUS) technologies

Advances in ultrasonography: image formation and quality assessment

Contact Info

Product

Resources

About