Letter to the editor

✍ Scribed by Jerome B. Jacobson; Wayne S. Chilcote

• Book ID: 102331468
• Publisher: John Wiley and Sons
• Year: 1975
• Tongue: English
• Weight: 261 KB
• Volume: 3
• Category: Article
• ISSN: 0091-2751
• DOI: 10.1002/jcu.1870030302

✦ Synopsis

The use of television displays in gray scale ultrasound has introduced a potentially serious measurement problem. The size of a structure may appear to vary, depending upon its location on the television screen. The degree of distortion can be estimated by placing B-scan marker dots in both horizontal and vertical positions and measuring a similar length in various areas.

I suspect the problem applies to most commercial units. Measurements from three units (two manufacturers) showed maximum distortions of 10, 1 2 and 16 per cent. The major distortions tended to be in one area of the horizontal display, and I have been told that this cannot be adjusted.

Accurate measurements can be made by avoiding areas on the screen that are known to have distortion or by placing the B-scan measuring dots in the same direction and location on the screen as the part to be measured. An alternative would be to take all critical measurements from a properly calibrated oscilloscope display.

Very truly yours,