Human microvascular imaging: a review of skin and tongue videomicroscopy techniques and analysing variables.

Imaging techniques are increasingly important in clinical diagnostic work. Microcirculation is essential for function and survival of all tissues, but imaging techniques for microvascular monitoring of patients have only been used to a limited extent in clinical practice. The microcirculation is complex with its static and dynamic feature, and only skin and oral mucosa are readily accessible for microscopic examination. In addition, there is a no general agreement on which microvascular parameters and analysing techniques that could be useful. The aim of this article is to give an overview of techniques for human intra-vital microscopy and to describe software and variables used to analyse pictures and film sequences of human microcirculation. We also present clinical examples where microvascular examinations have been shown to be of diagnostic value. Improved techniques for assessing microvascular morphology and physiology will probably become important tools in clinical work in many disciplines in the near future.