It is interesting to note that independent research was documented in the next issue of the same journal [1964;10(5):369] by Dr. Yong-Chang ZHOU, et al, from Shanghai Sixth Hospital, Shanghai, East China, where WANG had received his first ultrasound training.
In recognition of their contribution, Drs (now Professors) WANG and ZHOU were given a Pioneer Award jointly by the World Federation of Ultrasound in Medicine & Biology and the American Institute of Ultrasound in Medicine in 1988.
In 1967, Drs A Kratochwil and L Eisenhut published their fetal echocardiographic paper in German (The earliest detection of fetal heart activity by ultrasound. Geburtshilfe Frauenheilkd 1967; 27: 176-80. In 1972, Dr. F Winsberg published his paper Echocardiography of the Fetal and Newborn Heart [Invest Radiology 1972;7(3):152-8], which correlated M-mode findings to cardiac structures. The work is usually cited as the earliest fetal echocardiographic study by those who use English as their first research language.
In the late 70s and early 80's, the use of real-time directed M-mode echocardiography announced the new era for prenatal diagnosis of the fetal cardiac malformations. And these research works are well known to the people of related study fields.