Radiology 3: Study Guide

• Benefits of an ultrasonography

  • No radiation
  • Patient and technician safety
  • Allows continuous, moving, real time imaging
  • Good for soft tissue
  • Good for neonates
• Reasons to use a CT

  • Highlights soft tissue and bony structures
  • Looks at whole organs
• Reasons to use MRI

  • View the spinal chord and brain
  • Good for soft tissues (water based)
  • Good for joints
• 1. Mode (amplitude mode)


  Linear (single line through), Measures distances, Simplest form
• 1. Mode (brightness)


  Sector transmitter to see across ribs, Can see the different heart valves, Can see abnormalities (ex. tumors), 2d image
• 1. Mode (motion-mode)


  Motion and timing, View contraction of the heart, Moving things in the body
• How images are produced in MR

  1. Powerful magnet aligns polar water molecules in tissues

  2. Brief radio wave increases energy of water molecules

  3. Scanner measures energy as it is released from the tissues
• How an image is produced in Ultrasonography

  1. Emits a high-frequency sound = ultrasound

  2. Receives the echo reflected back from tissues
• How an image is produced in a CT

  1. Contains x-ray tube and detectors that rotate around the patient

  2. Narrow beam of x-rays is aimed at a patient and quickly rotated around the body, producing signals that are processed by the machine's computer to generate cross-sectional images, or "slices"
• Imaging that uses positive and negative contrast


  X rays
• What piezoelectric materials within a probe are capable of

  • Converts electrical energy into mechanical energy and vice versa
• Linear array probe


  Multiple transducers in a line, Rectangular image, Fine-detail imaging
• Curved away (convex) probe


  Multiple transducers in a fan, Curved image
• Sector/convex probe


  Transducers oscillate back and forth from a single point, Wedge shaped image, General scan
• Microconvex Transducer


  Much smaller footprint size, Smaller animals, Great for exotics, View between the ribs
• Matrix transducer


  Newest technology, Can create 3D images, Ability to scan in different planes at the same time
• Phased Array Sector Transducer


  Used for cardiac, Offers a CW mode, Piezoelectric elements that move in unison through complex timing to focus and steer sound beams at different depths at the same time
• Volume Transducer


  4 and 5 dimensional structures
• Angles used for bisecting angle technique


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