Introduction to Ultrasound




How does ultrasound (US) work?

Why US?

Advantages

  • Real time images

  • Cheaper and more readily available (point of care)

  • No radiation


Limitations​

  • Depth of penetration depends on body habitus

  • Technique/technician dependent

What is US?

  • A piezoelectric crystal within the ultrasound transducer vibrates, creating sound waves

  • As the waves pass through an object, they can either completely transmit, partially reflect, or get completely reflected at interfaces

  • Reflected waves will be picked up by the crystal in the transducer and converted into an image

Transducer Types

Linear transducer

  • Higher frequency

  • Higher resolution

  • Poor tissue penetration so better for superficial structures (soft tissue or thyroid US)

Curvilinear transducer

  • Lower frequency

  • Lower resolution

  • Better tissue penetration so better for deeper structures (abdominal or pelvic US)