Speed of Sound

Bamber, Jeffrey C.

doi:10.1002/0470093978.ch5

Cited by 26 publications

(19 citation statements)

References 79 publications

(114 reference statements)

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“…If the pulse shape changes due to dispersion in the measurement medium, due to frequency dependence of speed of sound or attenuation, then the definition of a single point of reference is difficult. The definition of first arrival as the time that the signal can be distinguished from the background noise, and the time of the first zero crossing have both been utilized (Bamber, 2004b). In this work the first zero crossing was used as the definition of first arrival time as this was more reproducible when considering the different signal attenuation from the various samples.…”

Section: Introductionmentioning

confidence: 99%

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Atkins

Humphrey

Duck

et al. 2010

J. Phys.: Conf. Ser.

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This thesis describes investigations into the design and evaluation of novel ultrasonic methods for 3-dimensional ionising radiation dose verification. Pulse-echo ultrasound methods were investigated for the measurement and analysis of complex radiation therapy dose delivery. The physical properties of MAGIC (Methacrylic and Ascorbic acid in Gelatin Initiated byCopper) polymer gel dosimeters have been characterized. The variations of speed of sound, ultrasonic attenuation coefficient and density of MAGIC gel with radiation dose and temperature have been quantified. This extends work that has previously been reported for the properties of this gel to the effect of measurement temperature on the results. The facilities to perform these measurements were specified, constructed and evaluated as part of the project.The measurement of radiation dose using ultrasound back scatter from an interface between the polymer gel dosimeter and an inert reflector is demonstrated. To enable the measurement of radiation dose using pulse-echo ultrasound methods a novel inert material has been specified, manufactured and characterised. This material is matched to the acoustic impedance of MAGIC gel to produce the most dose-sensitive reflections.The reflections from the interface between the inert reflector and dose-dependent MAGIC gel have been analysed using both a single element transducer and a commercial ultrasound scanner. Both measurement systems demonstrate the same dose and temperature dependence of the ultrasonic reflection. A methodology has been developed to relate pixel values from the ultrasound scanner to the amplitude of the reflected ultrasound signal. A phantom consisting of an array of threads formed from the inert backscattering material has been designed and constructed and a method of extracting pixel data from images of the array acquired using a commercial ultrasound scanner has been developed, so that multiple imaging positions could be used to perform a 3-dimensional assessment of radiation dose distributions.It has been demonstrated that a pulse-echo technique using a commercial ultrasound scanner shows promise for radiation gel dosimetry. Further investigation and alternative polymer gel and inert reflector combinations may improve these techniques.

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Section: Introductionmentioning

confidence: 99%

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Atkins

Humphrey

Duck

et al. 2010

J. Phys.: Conf. Ser.

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“…This is a consideration for the broadband system. Theoretical modelling (Bamber 2004) has demonstrated that changes in pulse shape may lead to overestimations in sound speed of up to 4% in longer sample path lengths with a higher attenuation coefficient relative to our experiment. The specimen path length is a maximum of 24 mm in the reflective technique.…”

Section: Uncertainties In the Measurementsmentioning

confidence: 44%

Carotid atherosclerotic plaque characterisation by measurement of ultrasound sound speed in vitro at high frequency, 20MHz

Brewin¹,

Srodon²,

Greenwald³

et al. 2014

Ultrasonics

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“…This widely known procedure is painless and safe. However, some important problems occur in such cases as, e.g., a significant degree of patient over-weight, ascites, intestinal gases and chronic flatulence [14]. Ultrasound has also trouble penetrating bone.…”

Section: Endoscopic Ultrasound Imaging (Eus)mentioning

confidence: 99%

“…The use of EUS can also assist controlling of the stents insertion and monitoring effects of treatment [19]. The complications are low, however, the safe and efficient use of EUS technique requires significant prior experience in endoscopy and abdominal ultrasonography as well as sufficient training with the technique itself [14,18]. On the other hand, obstruction from tumours (e.g.…”

Section: Endoscopic Ultrasound Imaging (Eus)mentioning

confidence: 99%

“…Modern imaging technology includes videoendoscopy, ultrasonography (USG), computer tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasonography (EUS) which make very advanced methods used in imaging of digestive tract diseases [10][11][12][13][14][15][16]. These methods are suitable for the detection of different properties of tissues through a variety of utilized phenomena.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Role of optical techniques in combined use of selected methods of medical imaging

Cysewska-Sobusiak

Wiczyński

Krawiecki

et al. 2008

Opto-Electronics Review

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The subject matter of this paper concerns advanced techniques of imaging used in diagnosis and minimally invasive procedures applied in non-operable cases of the digestive tract tumour therapy. The role of optical techniques in current medical imaging is significant. Optical properties of transilluminated or illuminated tissues and organs depend on strong light absorption and scattering. Numerous issues related to the result interpretation still remain unsolved. Effectiveness and precision can be especially improved when some combined methods of imaging are used. Videoendoscopy imaging, X-ray imaging, and endoscopic ultrasound imaging are three complementary methods applied during the interventions described in this work. All interventions have concerned with the upper part of the digestive tract. Especially, interdisciplinary issues of combined medical imaging are presented using some examples of a modern approach to imaging of esophagus and biliary stenting. The selected examples of effects obtained during interventions assisted by combined imaging of the operation site are presented. The operator can have great control over the appearance of desirable effects as well as undesirable complications in order to work comfortably and safe.

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Speed of Sound

Cited by 26 publications

References 79 publications

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry

Carotid atherosclerotic plaque characterisation by measurement of ultrasound sound speed in vitro at high frequency, 20MHz

Role of optical techniques in combined use of selected methods of medical imaging

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