Background and study aims: Endoscopic measurement of lesion size is important in the design and conduct of clinical trials, in determining prognosis and choosing forms of therapy. Endoscopes are constructed with wide-angle lenses that distort the image significantly by creating a relative compression of points in the periphery of the image.
Methods: Published studies on endoscopic lesion measurement were identified using a computerized search of electronic databases (MedLine).
Results and conclusions: Currently used clinical methods of estimating lesion size (visual estimation or comparison to a target of known size, e.g., open biopsy forceps) are flawed and inaccurate. Results from studies using image processing or the stereoendoscope are particularly promising for the future.