Basic Principles Outline

Basic Physical Principles

• Sound Waves

  • Rarefaction

  • Compression

  • Amplitude

  • Decibels

  • Acoustic Pressure

  • Propagation Velocity

  • Frequency

  • Frequency-Wavelength-Propagation Velocity Relationship

  • Penetration

  • Resolution-Penetration Relationship

  • Amplitude

Ultrasound Waves

• Tissue Interaction

• Reflection

  • Angle of Incidence

  • Dropout

  • Tissue Boundary Width

  • Specular Reflector

  • Acoustic Impedance

    • Density

    • Acoustic Impedance Mismatch

• Scattering

  • Hematocrit Effect

• Refraction

• Attenuation
  

Transducers 

• Piezoelectric Crystal

• Pulse Length

• Ring Down Time

• Depth of Structure

• Frequency Bandwidth

• Aliasing

• Transducer Components

• Piezoelectric Crystal Arrangement

  • Single/Double

  • Mechanical Transducer

  • Phased Array Transducer

    • Linear Array

    • Annular Array

• Sector Scanning

  • Beam Steering/Focusing

• Transducer Properties

  • Frequency

  • Focal Depth

  • Bandwidth

  • Aperture

  • Transducer Types (Alternate)

Ultrasound Beam 

• Unfocused Beam

  • Near Field

  • Focal Point

  • Far Field

  • Near Field Length

  • Divergence Angle

• Focused Beam

  • Focal Zone

  • Side Lobes

  • Grating Lobes

  • Beam Shapes

• Resolution

  • Axial Resolution

  • Lateral Resolution

  • Elevational Resolution

Indications and Complications

• Indications

  • Category I

  • Category II

  • Category III

Bioeffects and Biosafety

• Bioeffects

  • Thermal

  • Cavitation

  • Other

• Biosafety