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.
John J. Wild
Wild emigrated to the United States in 1946, taking a position at the University of Minnesota. After starting at the school's department of surgery, he shifted to the electrical engineering department in 1950. As a surgeon during World War II he had seen many patients who had suffered bowel failure experienced because of bomb explosions from German V-1 flying bombs and had developed a technique called the "Wild tube" to deal with the problem. After seeing patients in the U.S. with similar conditions, Wild conceived the idea of using ultrasound as a noninvasive means to determine the level of injuries suffered in the intestines of patients, with the sound bouncing back from the tissue identifying the thickness and resiliency of that portion of the intestine. He had developed the technique after having heard of high-frequency sounds being used as a means to identify cracks in tank armor. While the early machines operated at too low a resolution for the purpose of scanning the intestines, by 1951 he and Dr. John Reid gained access to equipment that operated at the 15 MHz range, providing the detail needed to scan internally and to distinguish between healthy and cancerous tissue. Wild and his team were able to take ultrasound scans of breast tissue that could be used as a noninvasive means to identify and diagnose tumors. Together with Reid, Wild developed tools for scanning rectal and vaginal tissues.