Non-invasive quantitative study of brain perfusion using sup(99m)Tc-pertechnetate

Using a standardized method, activity/time curves of cerebral perfusion were established over 7 fixed regions of interest. This is the first time that activity/time curves have been described by a mathematically defined adaptation function whose accuracy was checked over several regions of interest. From these adaptation functions, defined curve parameters (time values, pulse rates, 147 parameters per patient) were derived in order to obtain quantitative and qualitative perfusion curves over the various regions of interest. The patients with normal clinical and neurological findings were divided in two age groups. Within each group, normal ranges were calculated for all curve parameters. These normal ranges were used for evaluation of the data of patients with established vascular processes or brain tumours. In patients with several vascular processes, time values were significantly longer and pulse rates were clearly reduced. In patients with less severe vascular processes, time values were longer while the pulse rates remained unchanged. In order to make the method suitable for routine diagnosis, parameters of particular sensitivity were established on the basis of defined criteria, and a multiparameter system of 36 parameters was derived. The sensitivity and specificity of the multiparameter system were then tested in patients with established vascular processes. Compared with scintiscanning, the sensitivity was significantly higher while the specificity was slightly lower. Finally, patients with uncertain neurological symptoms were examined, and the findings were compared with those of sequential scintiscanning. (orig./MG)