Medical ultrasound
A contrast medium for medical ultrasonography is a formulation of encapsulated gaseous microbubbles to increase echogenicity of blood, discovered by Dr Raymond Gramiak in 1968 and named contrast-enhanced ultrasound. This contrast medical imaging modality is clinically used throughout the world, in particular for echocardiography in the United States and for ultrasound radiology in Europe and Asia.
Ultrasonography of chronic venous insufficiency of the legs
The Doppler effect was first described by Christian Doppler in 1843. Nearly forty years later in 1880, the piezoelectric effect was discovered and confirmed by Pierre and Jacques Curie. Both of these findings were used in the development of ultrasonography. The first ultrasound was applied to the human body for medical purposes by Dr. George Ludwig, University of Pennsylvania, in the late 1940s.