The Physics of Ultrasound

2018 ◽  
Author(s):  
Gerry van Rensburg ◽  
Andrew Smith ◽  
Ben O’Brien
Keyword(s):  
Continuous Wave ◽  
Imaging Modality ◽  
Doppler Frequency ◽  
Daily Practice ◽  
The Body ◽  
Ultrasound Images ◽  
Plain Language ◽  
Color Flow ◽  
Continuous Wave Doppler ◽  
Physical Principles

Clinical ultrasound has attained significant importance for the practising anesthesiologist. Its applications reach far and wide in anatomic and physiologic diagnosis, and it is a powerful adjunct for guiding interventional procedures. This article describes the physical principles that allow for the generation of ultrasound, its transmission and reflection from within the body, and generation of the ultrasound images used in daily practice. We not only review definitions of important technical terms but also provide synonyms in plain language, as jargon often presents a barrier to grasping basic and fundamental principles. Furthermore, we review the mathematical and physical principles that facilitate the generation of Doppler modes, such as pulsed wave, continuous wave, color flow. Clinically safe practice requires that all data be interpreted in the light of the technology’s shortcomings; we additionally review the common pitfalls and artifacts encountered in the use of this imaging modality. This review contains 16 figures, 1 table, and 5 references. Keywords: attenuation, continuous wave Doppler, Doppler, frequency, imaging artefacts, physics, pulsed-wave Doppler, ultrasound

scholarly journals Ultrasonography for diagnosis of peri-implant diseases and conditions: a detailed scanning protocol and case demonstration

2020 ◽  
Vol 49 (7) ◽  
pp. 20190445 ◽  
Author(s):  
Hsun-Liang Chan ◽  
Oliver D. Kripfgans
Keyword(s):  
Imaging Modality ◽  
Research Work ◽  
Diagnostic Value ◽  
Tissue Imaging ◽  
European Federation ◽  
Postoperative Phase ◽  
Ultrasound Images ◽  
Cross Sectional ◽  
Color Flow ◽  
Scanning Protocol

Objectives: Ultrasonography has shown its promising diagnostic value in dental implant imaging research in the three treatment phases, namely, planning, intraoperative, and postoperative phase. With increasing awareness of peri-implant diseases and a lack of an efficient diagnostic method, the aim is to propose ultrasound imaging as a potential solution by providing a detailed scanning protocol and case demonstration. Methods: Ultrasound device specification and the setup for optimizing peri-implant tissue imaging was described. Two useful imaging modes, viz. B-mode and color flow, were introduced. Important anatomical structures for accurate diagnosis of peri-implant diseases were illustrated. Finally, a detailed scanning sequence was proposed. Results: Ultrasound images were acquired on live humans to exemplify the four peri-implant diseases and conditions, endorsed by the 2017 World Workshop organized by the American Academy of Periodontology and the European Federation of Periodontology. Ultrasound can provide not only cross-sectional anatomical images but also functional images (color flow images) that may be useful for evaluating the degree of peri-implant tissue inflammation. Conclusions: High-frequency ultrasonography could be another cross-sectional imaging modality in adjunct to radiographs for diagnosing imminent peri-implant diseases and conditions that negatively influence quality of life of millions of patients with implants. This case study provides a framework for future related research work and clinical scanning guidelines.

Short-Time Fourier Transform of Continuous Wave Doppler Signals

1997 ◽  
Vol 503 ◽  
Author(s):  
Shi-Chang Wooh ◽  
Coach Wei ◽  
Arthur Clay
Keyword(s):  
Fourier Transform ◽  
Continuous Wave ◽  
Doppler Frequency ◽  
Doppler Frequency Shift ◽  
Ultrasonic Monitoring ◽  
Short Time Fourier Transform ◽  
Continuous Wave Doppler ◽  
Doppler Signals ◽  
The Time Domain ◽  
Short Time

ABSTRACTA Doppler-based ultrasonic monitoring scheme was introduced to detect discontinuities on the surface of a rapidly moving object. Single-tone, continuous wave (CW) ultrasound was impinged onto the moving surface and the reflected signal was processed by a Short-Time Fourier Transform (STFT) algorithm to identify surface anomalies. By monitoring the peak magnitude of the STFT spectra within a specified window, it was possible to reconstruct a signal representing Doppler frequency shift continuously in the time domain.

Assessment of aortic regurgitation by color flow and continuous-wave Doppler echocardiography

1996 ◽  
Vol 77 (8) ◽  
pp. 661-663 ◽  
Author(s):  
Prateek Dalal ◽  
Bibiana Nagy ◽  
Marvin Berger ◽  
Susan Hecht ◽  
Preston Hupart ◽  
...  
Keyword(s):  
Aortic Regurgitation ◽  
Doppler Echocardiography ◽  
Continuous Wave ◽  
Color Flow ◽  
Continuous Wave Doppler

scholarly journals Research on Mud Flow Rate Measurement Method Based on Continuous Doppler Ultrasonic Wave

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Quan Zhou ◽  
Hui Zhao ◽  
Yufa He ◽  
Shengnan Li ◽  
Shiquan Jiang ◽  
...  
Keyword(s):  
Doppler Ultrasound ◽  
Flow Rate ◽  
Continuous Wave ◽  
Doppler Frequency ◽  
Drilling Mud ◽  
Continuous Wave Doppler ◽  
Gas Kick ◽  
Annular Pipe ◽  
Judgment Data ◽  
Mud Flow

In deep-water drilling processes, the flow rate of drilling mud inside an annular pipe is significant judgment data for early kick detection. On the basis of the continuous-wave Doppler ultrasound, this paper proposes a new detection method of nonoriented continuous-wave Doppler ultrasound. The method solves the problem of the ultrasound having great attenuation in mud and not receiving effective signals by using a continuous ultrasound. Moreover, this method analyzes the nonoriented characteristics of ultrasound reflection on principle and proposes the detection of ultrasound Doppler frequency shift by detecting Lamb wave, which releases the detection of oil-based mud flow rate in a nonintrusive annular pipe. The feasibility of the method is verified through theoretical analysis and numerous experiments on a gas kick simulation platform. The measurement result has reached a flow accuracy approximating to the intrusive flow meter.

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