Some of these are free...some are for $$$.  At any rate, there are more than enough to keep your registry current. 

If you come across other sources, please let us know at echo@ghse.org.

Advanced Health Education Center

American Institute of Ultrasound In Medicine (AIUM)

Chrestomathic, Inc

The Online Learning Center for Medical Imaging Professionals

Siemens

GE

The Burwin Institute

CME Info.Com

CME Web

Echo Web: A Resource for Sonographers

ESP Ultrasound

Gulf Coast Ultrasound

Institute for Advanced Medical Education

Medscape CME Center

National Institutes of Health

Pacific Vascular Institute for Continuing Medical Education

Pegasus Lectures

Society of Diagnostic Medical Sonography

The Texas Heart Institute at St. Luke's Episcopal Hospital

Ultrasound Technician -A Resourceful Site for Sonographers

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