From A-mode to virtual beam: 50 years of diagnostic ultrasound

• Published in: The Journal of the Acoustical Society of America 2017-05, Vol.141 (5), p.3790-3790
• Main Author: Kremkau, Frederick W.
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4988354

In the 50 years from 1967 (the year that, as a student, I met Edwin Carstensen) to 2017, diagnostic ultrasound has progressed from A mode to M mode to B&W static 2D to gray-scale static 2D to real-time 2D to static 3D to real-time 3D (“4D”). Along the way, other modes and features appeared including analog-to-digital, color-, power- and spectral-Doppler, coded excitation, harmonic imaging, panoramic imaging, spatial compounding, contrast agents, elastography and virtual beam forming. Contrast agents have been in wide use globally for years, although limited in the U.S. by the FDA to cardiac application until recently. Contrast agents operate on the ability of gas bubbles to strongly reflect ultrasound. In a 1968 study conducted by Professors Carstensen and Gramiak and me, it was shown that the contrast effect was due to bubbles in the radiologic contrast agent. As an electrical engineering graduate student at the time, I could not know that this was the launching of a 50-year medical academic career in sonography. Prof. Carstensen was instrumental in guiding me into this exciting and rewarding career. This presentation concludes with a comparison of contemporary physical and virtual beam formation and its impact on image quality.