An optical coherence imager for use in a clinical environment includes a laser source (24) for illuminating an area of tissue surface and a detector array (28) arranged to generate output signals indicative of detected light scattered from the tissue surface. An optical coherence image, such as a Flux image that is indicative of blood perfusion in the tissue, is generated from data collected at the detector. Detector output is analysed to identify a time series of such optical coherence images during which relative movement between tissue and detector is favourable. A representative optical coherence image is formed from an average of optical coherence images generated from data collected within the identified time series and extending over a period of multiple heartbeats. The representative optical coherence image thereby exhibits minimal movement noise and the effects of heartbeat are averaged out.