[Endoscopic determination of the size of gastrointestinal ulcers (author's transl)].

A new method based on computer-assisted semi-automatic equipment for stereological analysis has been developed to measure ulcer size endoscopically. The main component is a graphic measuring table connected with a computer which is itself linked to a television monitor. The endoscopic picture is transmitted to the television monitor and the ulcer area is measured directly on the monitor using electronic overlay markers. The trace of the measuring markers remains visible on the monitor so that every lesion demonstrated is accurately outlined. The computer calculates the ulcer area by relating it to a known endoscopically inserted reference area. Numerous measurements from various distances, various angles of view and with variable reference area sizes showed the error to be 4.2 +/- 0.5%. Measurements by six different investigators showed variations of 2.9 +/- 1.2%. These results document the reliability of endoscopic planimetrics of gastrointestinal ulcers.