Figure 4. The false-negative and false-positive cases
Top: Side by side view of W and S-A images of a keratotic lesion on the left vocal cord, patient #14. Dilated and tortuous vessels around the white keratotic patch (arrows) are classified as longitudinal (false-negative) although the lesion truly is a low-grade dysplasia.
Central: W and S-A images of a granulation tissue on the left vocal cord, occurred 3 months after laser cordectomy (patient #1). The circled area contains worm like vessels with small sharp turns, lacking a longitudinal orientation, and were classified improperly as perpendicular (false-positive).
Bottom: W and S-A images of a benign granular cell tumor on the left vocal cord (patient #4). Worm like vessels (arrows) were classified as perpendicular (false-positive).