Abnormal microcirculation in brain tumours during surgery

Orthogonal Polarisation Spectral imaging is a new clinical technique that u ses polarised light to visualise the microcirculation of organ surfaces. We have used this technique to compare the functional microcirculatory proper ties of three types of brain tumour with those of the normal cortex. Mening iomas were characterised by chaotic and dilated vessels with almost no eryt hrocyte movement and a dark background, glioblastoma by few vessels with lo w flow and a background close to that of the healthy cortex, and metastases by a very dark background, almost no flow, and a chaotic vascular pattern. This technique could provide useful information about microcirculatory mor phology and kinetics for diagnostic use during neurosurgery.