Fig. 4.

Scanning darkfield images consistently shows improved image contrast compared to widefield images. (A) Comparison of representative images acquired using widefield imaging and scanning darkfield imaging at different anatomic sites in the oral cavity of a healthy volunteer. Images were acquired using a probe with a 70 µm imaging depth. Corresponding intensity profiles along the red dashed lines are plotted for each image pair. Red arrows indicate the microvascular features that are clearly resolved in darkfield images but not distinguishable in widefield images. Black brackets denote vessels resolved in darkfield images. (B) Relationship between widefield and darkfield image contrast from 25 randomly selected microvessels. Each point indicates the contrast of one microvessel. WF: widefield imaging; DF: scanning darkfield imaging. (Scale bar: 100 µm)