Summary
Current endoscopic measurements of gastrointestinal ulcer area using forceps or graduated
probes are associated with a high degree of inaccuracy.
Based on a computer-assisted, semiautomatic device for stereological analyses, we
have developed a new method for the endoscopic determination of ulcer size. The basic
elements are a graphical measuring tablet coupled with a computer, the latter being
connected to TV-monitor. The endoscopic picture is transmitted to the TV-monitor and
the ulcerated area is measured directly on the TV-monitor by means of an electronic
overlay marker. The trace of the marker remains visible on the screen so that any
circumscribed lesion can be labelled exactly. From the relation of a known, endoscopically
introduced reference area to the circumscribed ulcerated area, the latter is calculated
by the computer. Multiple measurements obtained at different distances, and visual
angles, and with different reference areas, revealed an error of 4.2 ± 0.5 %. Inter-observer
variation among 6 different examiners was 2.9 ± 1.2 %.
These results document the reliability of endoscopic planimetry of gastrointestinal
ulcers.
Key words:
Endoscopic Planimetry - Ulcer Area
