10.2 Diagnostic ultrasound

• The frequency of a sound wave is measured in Hertz
• Ultrasound has a frequency above 20 kHz
• What happens to an ultrasound wave when it encounters a boundary between two materials with different acoustic impedances?

  Part is reflected
• What effect do transducers in diagnostic ultrasound utilize?

  Piezoelectric effect
• Transducers can focus the sound beam using acoustic lenses or curved surfaces


  True
• What is the unit for measuring wavelength?

  Meters
• What is the purpose of ultrasound in medical imaging?

  To image internal structures
• The time taken for an echo to return is used to calculate the depth
• Transducers convert electrical energy into sound waves during transmission
• The transducer is the key component that enables the generation, transmission, and detection of ultrasound waves.
• Ultrasound refers to sound waves with a frequency above 20 kHz.
• The angle of reflection equals the angle of incidence for ultrasound waves.


  True
• Transducers in diagnostic ultrasound utilize the piezoelectric effect.
• Steps in the image formation process in ultrasound imaging:

  1️⃣ Reflection of ultrasound waves at boundaries

  2️⃣ Detection of echoes by the transducer

  3️⃣ Calculation of depth using echo return time

  4️⃣ Building an image from multiple echoes
• M-mode ultrasound is used to track the movement of structures over time.
• What is the frequency range of ultrasound in diagnostic applications?

  Above 20 kHz
• What is the speed of sound in air under typical conditions?

  343 m/s
• What effect do transducers in ultrasound use to convert energy?

  Piezoelectric effect
• What is the typical frequency range of transducers used in medical ultrasound imaging?

  2-10 MHz
• Steps in the image formation process in diagnostic ultrasound:

  1️⃣ Reflection of ultrasound waves at boundaries

  2️⃣ Detection of echoes by the transducer

  3️⃣ Processing of echoes to build a 2D image
• When an ultrasound wave encounters a boundary with different acoustic impedances, part of the wave is reflected
• Part of an ultrasound wave is reflected at a boundary, while part is transmitted
• The amplitude of a reflected wave depends on the difference in acoustic impedance between materials.


  True
• What is the time of flight in ultrasound imaging used to calculate?

  Depth of structure
• What is the typical frequency range of ultrasound waves used in medical imaging?

  2-10 MHz
• The choice of ultrasound mode depends on the specific clinical application
• What type of waves are sound waves?

  Mechanical waves
• The speed of sound in air is approximately 343 m/s


  True
• Ultrasound imaging relies on the reflection and detection of high-frequency sound waves


  True
• Steps in the ultrasound imaging process

  1️⃣ Reflection of ultrasound waves at boundaries

  2️⃣ Detection of echoes by the transducer

  3️⃣ Calculation of depth from echo time

  4️⃣ Building an image by detecting multiple echoes
• Which materials are commonly used as piezoelectric materials in transducers?

  PZT and quartz
• What unit is used to measure frequency in sound waves?

  Hertz
• What is the primary principle of ultrasound imaging?

  Reflection and detection
• Match the piezoelectric material with its common use:

  Quartz ↔️ Transducers

  Lead Zirconate Titanate (PZT) ↔️ Medical imaging

  Barium Titanate ↔️ High-frequency transducers
• B-mode ultrasound imaging generates a 2D image based on the brightness of reflected waves.

  True
• Which ultrasound mode measures the frequency shift of reflected waves to analyze blood flow?

  Doppler
• Sound waves are mechanical waves that propagate through a medium by causing particle vibrations.


  True
• The principle of ultrasound imaging relies on the reflection and detection of high-frequency sound waves.


  True
• Match the wave property with its behavior at a boundary:

  Reflected Wave Amplitude ↔️ Depends on impedance difference

  Reflected Wave Angle ↔️ Equals angle of incidence

  Transmitted Wave Angle ↔️ Differs from incident angle
• Transducers convert electrical energy into sound waves during transmission and sound waves into electrical signals during reception.


  True