The Vidoson used 3 rotating transducers housed in front of a parabolic mirror in a water coupling system and produced 15 images per second. The image was made up of 120 lines and basic gray-scaling was present. The use of fixed focus large face transducers produced a narrow beam to ensure good resolutions and image. Fetal life and motions could clearly be demonstrated. Malte Hinselmann, using the Vidoson, demonstrated in 1969 the universal visualization of fetal cardiac action from 12 weeks onwards.
The Vidoson was popular in the ensuing 10 years or so and were used in many scientific work published from centers in Belgium, Italy, Germany, Vienna and North America. The initial popularity was not based on its image resolution but rather its ability to allow the operator to display and study movements, such as fetal cardiac motion, gross body movements and fetal breathing movements. In the International Symposium on real time ultrasound scanner in Perinatal Medicine held in Charleroi, Belgium in 1978, most of the presentations were based on results from the Vidoson. James Griffith and Walter Henry produced a mechanical oscillating real time ultrasound scanner in 1973 which was capable of producing clear 30 degree sectoral real-time images of good resolution. The transducer was employed extensively in cardiac scanners and the design was hailed as one of the significant milestones in the development of echocardiography.
Other mechanical systems published included an oscillating design with membrane-oil coupling from W N McDicken in Edinburgh (1974, produced commercially as the EMI® Emisonic 4260), a continuously rotating wheel with radially-mounted transducers from Hans Hendrik Holm in Denmark (1975), and a single transducer direct-contact design from Reginald Eggleton in Indiana (1975). Toshiba®, in Japan produced their first prototype real-time mechanical sector scanner in 1975, the SSL-51H. A number of others were available commercially soon afterwards and sold well such as the circular rotating system Combison 100 from Kretztechnik® of Austria (1977), produced under the ingenuity of Carl Kretz. Although these have relatively heavy probes they produced outstanding real time resolution in the near and far field (because of highly focused beams resulting from the relatively large curvatured transducers and the lens apparatus) and with much less image-degrading electronic noise that was associated with electronic scanners that soon became available at around the same time.
The invention of the real time ultrasound scanner had enabled much more effective diagnosis of many fetal malformations and in particular cardiac anomalies which hitherto was impossible to diagnose accurately. Fetal sonography and prenatal diagnosis (a term which was only coined in the 1970s) had emerged as the 'new' science in Obstetrics and fetal medicine. Ninety one patients with urinary tract abnormalities diagnosed before birth were reviewed.
Diagnoses based on prenatal and postnatal real time ultrasound scanner alone were compared with the final diagnoses after full urological ultrasound investigations, with operative or necropsy confirmation in 79 cases. The results confirmed that ultrasound examination before birth usually detects nonspecific abnormalities and although scanning after birth is more accurate it is not absolutely reliable. A diagnosis of "multicystic kidney' made on real time ultrasound scanner alone is especially prone to error. Such mistakes can be avoided if full urological ultrasound and surgical ultrasound investigation is undertaken in every case.