Introduction. We examined the experience of performing perfusion studies of the brain, and analyzed the errors in the procedure and interpretation of studies. The data obtained made possible to understand better the reasons that led to errors and how to avoid them in future practice. Purpose: to reduce the number of perfusion studies of the brain, which interpretation is not possible or might be performed with errors. Objectives: to analyze the reasons that led to the inability to analyze the perfusion or difficulties in interpretation of the data obtained, to divide them into groups of factors that influenced the study. To develop an algorithm to reduce the number of «unsuccessful» studies. Materials and methods: retrospectively evaluated 275 CT and MRI studies of brain perfusion performed between 2017 and 2019. Results: the result of this study was a reduction of the number of uninformative studies and errors in the interpretation of correctly obtained data. Conclusion: monitoring the MRI and CT perfusion studies allows to avoid uninformative studies. The standardization of the examination method allows to evaluate the dynamics of changes, regardless of modality.