This chapter describes theories and technologies about ultrasound imaging. As a mechanical wave, ultrasound propagates in the imaging zone, and the echoes deliver information about the position and properties of non -uniformities inside the specimen. The most commonly used device for ultrasound transmission and reception is piezoelectric ultrasound transducers and their arrays. Vibration modes and design principles were discussed in detail. Other ultrasound transmission and/ or reception technology include CMUT and optical -based acoustic sensing. Multiple imaging modes are available in ultrasound imaging. Finally, typical ultrasound imaging modes are described, including A -mode, B -mode, M -mode, IUVS, Doppler imaging and harmonic imaging modes.

Chapter Contents:

• List of abbreviations
• 14.1 Introduction
• 14.2 Ultrasound wave
• 14.2.1 Fundamentals of acoustic wave
• 14.2.1.1 Longitudinal vibration of bars
• 14.2.1.2 Vibration modes of bars with boundaries
• 14.2.2 Ultrasound beams
• 14.2.2.1 Plane wave
• 14.2.2.2 Three dimensional wave
• 14.2.2.3 Spherical wave
• 14.2.2.4 Piston-shaped source
• 14.2.3 Reflection and scattering
• 14.2.4 Attenuation
• 14.2.5 Doppler shift
• 14.2.6 Nonlinearities in ultrasound imaging
• 14.3 Ultrasound sensors
• 14.3.1 Piezoelectric ultrasound transducers
• 14.3.1.1 Piezoelectricity
• 14.3.1.2 Piezoelectric materials
• 14.3.1.3 Transduction between electrical and mechanical waves
• 14.3.1.4 Matching layer
• 14.3.1.5 Backing layer
• 14.3.1.6 Typical structure of a piezoelectric ultrasound transducer
• 14.3.2 Piezoelectric array
• 14.3.2.1 Typical array structures
• 14.3.2.2 Array excitation modes
• 14.3.3 Capacitive micro-machined ultrasound transducers
• 14.3.4 Optical ultrasound sensors
• 14.3.4.1 Fibre Bragg grating
• 14.3.4.2 Fabry-Perot interferometer
• 14.3.4.3 Laser Doppler vibrometer
• 14.4 Ultrasound imaging
• 14.4.1 Ultrasound imaging system
• 14.4.2 Amplitude mode (A-mode) ultrasound imaging
• 14.4.3 Brightness mode (B-mode) ultrasound imaging
• 14.4.4 Motion mode (M-mode) ultrasound imaging
• 14.4.5 Intravascular ultrasound (IVUS) imaging
• 14.4.6 Doppler ultrasonography
• 14.4.7 Harmonic imaging
• 14.5 Summary
• References

Inspec keywords: piezoelectric transducers; sensor arrays; ultrasonic transmission; ultrasonic imaging; ultrasonic transducer arrays; ultrasonic propagation; image sensors

Other keywords: CMUT; harmonic imaging modes; B-mode; ultrasound transmission; ultrasound reception; ultrasound imaging sensors; piezoelectric ultrasound transducers; optical-based acoustic sensing; ultrasound propagation; Doppler imaging modes; M-mode; A-mode; IUVS

Subjects: Piezoelectric devices; Image sensors; Sonic and ultrasonic transducers and sensors