PHY541 Ultrasound Physics & Instrumentation (8)

Abstract

This subject provides a cohesive presentation of the physics and instrumentation of modern diagnostic medical ultrasound. It covers ultrasound wave properties, ultrasound propagation and attenuation in body tissue, ultrasonic transducers and their beam properties. The subject closely links these physical principles to the operation of modern diagnostic ultrasound instrumentation, such as two-dimensional, real-time scanning machines, M-mode scanners, and Spectral-, Colour- and Power- Doppler instrumentation. Recent advances in transducer- and imaging- technology are also discussed. The subject looks at the physics of blood flow, i.e. haemodynamics, and also covers quality assurance of ultrasound equipment, together with ultrasound bioeffects and safety considerations.

+ Subject Availability Modes and Location

Session 1
Distance*	Wagga Wagga Campus
Session 2
Distance	Wagga Wagga Campus

*This subject offering contains a residential school. Please view following information for further details.

Continuing students should consult the SAL for current offering details: PHY541
Where differences exist between the Handbook and the SAL, the SAL should be taken as containing the correct subject offering details.

Subject information

Duration	Grading System	School:
One session	HD/FL	School of Biomedical Sciences

Enrolment restrictions

Available only to students enrolling in the Grad Dip / MAppSc (Medical Ultrasound) courses.

Objectives

Upon successful completion of this subject, students should:
describe and perform relevant mathematical calculations pertaining to the physical properties of diagnostic ultrasound and its interaction with body tissue.
describe the properties, operation and applications of different varieties of modern real-time diagnostic ultrasound transducer probes.
explain the purpose, and describe the operation of current mainstream diagnostic ultrasound modalities (instrument systems), and understand some relevant quality assurance procedures.
recognise, and explain the physical basis underlying imaging/scanning artefacts associated with all modalities studied.
describe and perform calculations relating to the physical principles governing blood-flow in the human body (haemodynamics), and its relevance to Doppler ultrasound.
describe the different possible ultrasound bioeffects and their responsible damage mechanisms, together with international safety recommendations and guidelines.
describe a number of recent advances in ultrasound imaging technology, including harmonic imaging, 3-D imaging, multi-hertz imaging, confocal imaging, high-definition imaging, and the increasing use of contrast agents.
continue the independent-learning process and keep pace with the literature on new advances in ultrasound technology.

Syllabus

The subject will cover the following topics:
1. Basic Ultrasound Wave Theory wave definition and classification, wave pulses, spherical and planar waves, sound wave production, Hookes Law, particle velocity, bulk modulus, displacement- and pressure- expressions of a sound wave, specific acoustic impedance, absolute ultrasound intensity, relative intensity in dB. 2. Ultrasound Propagation & Attenuation reflection and refraction of ultrasound at specular/planar surfaces, Huygens principle, Snells law, critical angle, total reflection, amplitude- and intensity- reflection (R) and transmission (T) coefficients, impedance matching, transmission through layers, quarter-wave matching, mechanisms of ultrasound absorption, ultrasound scattering, Rayleigh scattering, frequency dependence of absorption and scattering, wave divergence, mode-conversion, intensity attenuation coefficient (in dB/cm/MHz), frequency dependence of attenuation for different body tissues, half value layers. 3. The Ultrasonic Transducer piezoelectric effect, natural and ceramic piezoelectric crystals (quartz, PZT, etc.), induction of piezoelectricity in PZT, Curie temperature, PVDF, piezoelectric constants, acoustic vs. electrical impedance of transducer crystal, transducer resonance, mechanical Q-factor, fundamental resonance frequency, harmonic resonances, frequency response curves, pulse frequency spectrum, pulse damping and log decrement, frequency bandwith of transducer, transducer material selection criteria, thickness expander mode, basic transducer probe construction - backing, front-end acoustic matching, electrical matching, optimum power transfer, tuning inductor, introduction to modern multi-element transducers, advantages of ceramic-epoxy composite transducers. 4.The Ultrasound Field CW field of planar single-element disc transducer, near field (Fresnel zone), far field (Fraunhofer zone), near field intensity distribution: axial and radial intensity fluctuations, PW field, far-field intensity distribution, directivity factor, side-lobe dependence on crystal radius and wavelength, beamshape dependence on crystal diameter and operating frequency, iso-echo contour plots, mechanical beam focussing (external and internal), multielement transducer beam patterns - linear-, curvilinear-, phased-, annular-, and rectangular- (2D-) arrays. 5.A- and M- mode Scanning Pulse-echo ranging, A-mode scanning instrumentation, TGC, pulse-repetition frequency/period, axial resolution, spatial pulse length, A-mode artifacts, acoustic coupling, M-mode scanning instrumentation and applications, M-mode artifacts, power and intensity in PW ultrasound, duty-factor, SATA, SAPA, SATP, SPTA, SPPA, SPTP average-intensity descriptors. 6.Static B-mode & Real-time, grey-scale Scanning static B-mode instrumentation, compound scanning, interlaced raster scanning, frame-rates, image flicker, digital scan converters, A/D and D/A converters, bit-depth, matrix memory size, pre-processing (log-compression, fill-in interpolation, edge-enhancement, image-updating, write-zoom and panning), post-processing (grey-scale mapping, contrast-enhancement, black-and-white inversion, freeze-frame, frame-averaging, read-zoom and smoothing), axial and lateral resolution, frame-rates, scan-lines, spatial- vs. motion- (time-) resolution, grey-scale artifacts (attenuation-, propagation- and miscellaneous artifacts), mechanical real-time scanning (contact- and liquid-path scanning), electronic real-time scanning (using annular-, linear-, phased-, curvilinear/convex-, rectangular-/2D- arrays), transmit/receive channels, channel element time-delay calculations for electronic focussing and steering, multi-zone transmit focussing, co-processing, dynamic receive focussing, dynamic aperture, broadband transducers, multi-hertz imaging, confocal imaging, HDI, endosonographic probes, harmonic imaging, 3D imaging, use of contrast agents, US equipment QA. 7.Haemodynamics blood viscosity, laminar flow, parabolic velocity profile, Poiseuille's Eq

Residential School

This subject contains a compulsory 5 day residential school.

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The information contained in the 2014 CSU Handbook was accurate at the date of publication: 27 June 2013. The University reserves the right to vary the information at any time without notice.

Handbook 2014