Editing Perfusion (section)

===Thermal diffusion===
{{main|Molecular diffusion}}
Perfusion can be determined by measuring the total [[Molecular diffusion|thermal diffusion]] and then separating it into [[thermal conductivity]] and perfusion components.<ref>{{cite journal  |vauthors=Vajkoczy P, Roth H, Horn P, et al |title=Continuous monitoring of regional cerebral blood flow: experimental and clinical validation of a novel thermal diffusion microprobe |journal=Journal of Neurosurgery |volume=93 |issue=2 |pages=265–74 | date=August 2000 |pmid=10930012 |doi=10.3171/jns.2000.93.2.0265|s2cid=30375395 }}</ref> [[rCBF]] is usually measured continuously in time.  It is necessary to stop the measurement periodically to cool down and reassess the [[thermal conductivity]].{{citation needed|date=March 2021}}