Revised 8/2008 NOVA COLLEGE-WIDE COURSE CONTENT SUMMARY DMS 209 - ULTRASOUND PHYSICS AND INSTRUMENTATION II (2 CR.) Course Description Focuses on the areas of ultrasonic, instrumentation, image artifacts, biologic effects, quality control as well as Doppler principles and applications and basic types of equipment through lecture and laboratory exercises. Lecture 2 hours per week. General Course Purpose The purpose of this course is to introduce students to the advanced study of acoustical physics. Course Prerequisites/Co-requisites Prerequisite is DMS 208. Course Objectives At the completion of this course the student will be able to: • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Identify the information presented in a spectral Doppler display. Differentiate factors that impact the characteristics of spectral Doppler waveforms. Compare and contrast the spectral waveforms of laminar and turbulent flow. Describe factors that influence laminar and turbulent flow. Describe the effects of stenosis on flow characteristics. Describe the Doppler waveform changes associated with proximal and/or distal stenosis. Relate changes in peripheral vascular resistance to characteristics of the spectral Doppler waveform. Describe the effects of hydrostatic pressure, calf muscle pump, and respiration on venous flow. Predict how the Doppler effect varies with changes in physiologic states. Identify the typical values of the Doppler shift. Describe the optimal Doppler angle for a specific sonographic examination. Describe the basic operational differences between PW and CW Doppler instrumentation. Compare and contrast the advantages and disadvantages of CW and PW and color Doppler equipment. Compare and contrast the color Doppler display to the direction of flow. Identify the ultrasound system controls that may be used to increase pulse repetition frequency (PRF) and reduce aliasing. Discuss the function of the fast Fourier transformer (FFT). Describe the effect of the quadrature phase detector on the Doppler shift. Compare and contrast color maps. Describe the effect of color Doppler on frame rates. Describe the system location and function of autocorrelation. Differentiate color and power Doppler and related sonographic applications. Describe the clinical applications of the range equation. Compare and contrast the major functions of each component of a diagnostic ultrasound machine. Identify which components are under operator control and the system control for that component. Discuss the dynamic range of the signal as the signal flows through the imaging circuit. Describe how the image changes as the dynamic range changes. Predict methods to increase the signal to noise ratio. Decide when to adjust the systems overall gain, TGC, reject, transducer frequency, and dynamic range based on image variations. Describe the echo amplitude sampling methods of the DSC. Describe what influences the shade of gray and the number of shades in digital memory. 1 • • • • • • • • • • • • • • • • • • • • Relate spatial resolution to the number of pixels and the field of view. Relate contrast resolution to the memory size and the number of matrix boards available. Compare the effects of pre processing versus post processing controls on the displayed image. Sequence an electron through the components of a cathode ray tube. Compare and contrast a TV monitor to a computer monitor with respect to frames per second, interlacing, and interpolation. Describe the methods used to produce an ultrasound image on film, laser imagers, (color) thermal printers, video tape, MOD, and CD. Describe the advantages and disadvantage of different storage media. Explain the signal to noise ratio and the techniques used to enhance a diagnostic image. Describe the production, image characteristics, clinical examples, and techniques to eliminate or minimize artifacts. Identify ultrasound artifacts. Describe the purposes and the requirements of quality control (QC). Compare and contrast multipurpose phantoms versus test objects. Explain the importance of each QC parameter. Predict image consequences when a QC parameter becomes nonstandard. Describe instrument output measurements. List typical output values for an ultrasound machine. Differentiate between labeling standards for machine output. Describe the importance of ALARA (As Low As Reasonably Achievable) principles. Explain ultrasound bioeffects in animals and humans. Describe the importance of national guidelines and regulations. Major Topics to be Included 1. Doppler instrumentation and hemodynamics a. b. c. d. e. f. g. h. i. j. Doppler effect Factors influencing the magnitude of the Doppler shift frequency Continuous wave and pulsed wave Doppler Doppler PRF, Nyquist limit and aliasing Color flow imaging Power Doppler imaging Duplex Doppler imaging Spectral analysis Doppler artifacts Hemodynamics (laminar and turbulent flow, velocity profiles, energy, etc.) 2. Quality assurance / quality control of equipment a. Preventive maintenance b. Malfunctions c. Performance testing with phantoms 3. Pulse-echo instrumentation a. b. c. d. e. f. g. h. i. Display modes and their formation (A-mode, B-mode, M-mode, 3-D, etc.) Transmission of ultrasound Reception of ultrasound (preprocessing) Beam former Postprocessing of ultrasound signals Pulse-echo imaging artifacts Tissue harmonic imaging Realtime ultrasound instrumentation Recording and storage devices, bioeffects and ALARA 2