Magiscan Image Analyrer

A software package which enables tine-angiocardiograms (X-ray pictures of the beating heart, recorded on standard 35- mm tine film) to be analysed automatically to show up ab- normal features signifying various kinds of malfunction has been developed by the Wolfson Image Analysis Unit at Manchester University Medical School, England.

The programs can also compute automatically all common func- tional indices of the heart (whether healthy or diseased), including ventricular volume, filling rate, ejection rate, ejection fraction, stroke volume and car- diac output.

The package is available under licence from Joyce-Loebl of Gateshead, England, (a divi- sion of Vickers Ltd.), who make the Magiscan image-analysis sys- tem to which the software is applied. The first hospital instal- lation of the system will be at Great Ormond Street Hospital for Sick Children in London.

The programs automatically scan the tine images for a boun- dary generally similar in shape to a stored ‘model’ boundary of the ventricle. On the first frame only, the operator assists the search by indicating five reference points round the boundary. The Magi- scan’s computer then locates and can display the complete edge of the ventricle; it does this by com- puting changes in image intensity

Figure 1 System 185 used for obstetric examination.

and by logical extrapolation from sections of the boundary already found. During the 9 seconds this takes, the operator can intervene to modify the outline as neces- sary.

The system goes on fully auto- matically to detect similar boun- daries for a complete cardiac cycle, comprising perhaps 25 frames photographed at 30-msec intervals. It predicts new edge positions from the direction and speed of movements in previous frames, then interprets brightness patterns as before.

Joyce-Loebl Marquisway, Team Valley, Gateshead NE1 1 OQW, UK

Ultrasound Scanner

The new System 185 is a major development of the original con- cept of System 85. The most

important new feature of System 185 is the incorporation of elec- tronic dynamic focusing which contributes much to the overall resolution improvement. Other electronic refinements have been made to optimize the production of consistently good, high reso- lution, greyscale images.

The System 185 digital calliper can measure accurately in any direction and also allows simul- taneous measurements to be made on A-scan, a technique accepted as the most accurate method of measuring biparietal diameters-especially in the third trimester. The frame freeze faci- lity is a practical aid to measure- ment and photography and the frozen image is stored for later comparison with the current real time image. The lightweight transducers have 85 elements which increase the number of genuine information lines, improving lateral resolution and giving a superior image. A new large-screen, high intensity display monitor giving greyscale images has also recently been developed. for use with System 185.

Diagnostic Sonar Ltd, 1 Grange Road, Houston Industrial Estate, Livingston, EH54 5DE Scotland, U.K.

J. Biomed. Engng. 1980, Vol 2, July 241