Are available methods for assessment of cerebral perfusion sufficient for scientific studies or not

: In this issue of Acta Anaesthesiologica Scandinavica, Chaix et al report results from a study where the effects of hypotension by general anaesthesia on cerebral perfusion is presented. The results given derive from a prospective observational study including patients requiring general anaesthesia during scheduled elective interventional neuroradiology procedures. The primary aim, according to the study, was to describe changes in cerebral perfusion in relation to hypotension measured with transcranial doppler (TCD).