Ultrasound

Diagnostic ultrasound is a powerful, non-invasive medical tool for real-time imaging of the fetus, internal organs of the body such as the heart, liver and gallbladder, as well as major veins and arteries. Blood flow can also be imaged or measured. The basis of operation for diagnostic ultrasound is the transmission into the body of sound (or acoustic radiation) at frequencies 100 - 500 times higher than can be heard. Images are then created by reception, processing, and display of echoes reflected from structures, tissues and flowing blood. The technique is similar to how bats, whales, and dolphins use echolocation, or how submarines use SONAR.

Ultrasound is also used for physiotherapy treatment, particularly for joints. A new and growing use is ultrasound as a surgical tool for destroying abnormal tissue growths or tumours. Ultrasound is also used extensively in industrial, commercial, military and home applications such as ultrasonic drilling, welding, cleaning, alarms, and animal repellants.

There are concerns about the safety of ultrasound because it is a form of energy which, above certain thresholds, can cause destructive heating and/or interaction effects with microscopic bubbles in the body. A cautious approach should therefore be taken in its use.

For general information about the benefits and risks of using diagnostic fetal ultrasound

• It’s Your Health: Fetal Ultrasound for Keepsake Videos

For guidelines and regulations related to ultrasound

• Food and Drugs Act
  
  
  • Medical Devices Regulations
    
    
    • Guidance for Manufacturers Preparing Device Licence Applications for Ultrasound Diagnostic Systems and Transducers
      
      
    • Notice to Industry - Risk Classification of Diagnostic Ultrasound Systems and Transducers
      
      
• Guidelines for the Safe Use of Diagnostic Ultrasound, 2001
  
  This update replaces all parts of Safety Code 23 “Guidelines for the Safe Use of Ultrasound – Part 1: Medical and Paramedical Applications (1989)” pertaining to the safe use of diagnostic ultrasound devices. Several developments in the past decade have necessitated this update.
  
  
• Guidelines for the Safe Use of Ultrasound: Part I - Medical and Paramedical Applications
  
  This excerpt contains the safe use guidelines for ultrasound therapy devices from Safety Code 23 - Guidelines for the Safe Use of Ultrasound, Part I, Medical and Paramedical Applications, 1989. Ultrasound therapy devices are used in physiotherapy. The guidelines complement legislation controlling the sale, lease, importation and advertising of ultrasound therapy devices in Canada, to help ensure that physiotherapy using ultrasound is safe.
  
  
• Radiation Emitting Devices Act
  
  
  • Radiation Emitting Devices Regulations
    
    
    • Part XIII Ultrasound Therapy Devices
      
      
• Safety Code 24. Guidelines for the Safe Use of Ultrasound: Part II - Industrial and Commercial Applications, 1991
  
  Provides guidance on the safe use of ultrasound in commercial and industrial applications. the recommended safety procedures and protective measures are based upon information provided here on the health effects of both contact and airborne ultrasound exposure.
  
  
• Selling Ultrasound Therapy Devices in Canada: What You Need to Know
  
  

For information on what Health Canada does to protect Canadians in this area

• Acoustics
  
  

To make an inquiry regarding ultrasound

• Contact the Consumer and Clinical Radiation Protection Bureau