• References

    Doppler. Radiological Society of North America Electronic Journal website. Available at: Accessed November 19, 2012.

    General ultrasound imaging.
    Radiologic Society of North America Radiology Info website. Available at:
    . Updated July 2, 2012. Accessed November 19, 2012.

    Radiation-emitting products. US Food and Drug Administration website. Available at: Updated June 6, 2012. Accessed November 19, 2012.

  • Resources

    American Institute of Ultrasound in Medicine—Radiologic Society of North America

  • Canadian Resources

    The College of Family Physicians of Canada