The study was undertaken to define the possibilities of using postmortem MRI for examining the brain. A complex study was made to explore 21 neutral formalin-fixed gross brain specimens from patients with neurosurgical pathology. Macroscopic and target histological studies of the changed signal areas detected by MRI were performed using histochemical stains. The significance of the results obtained by MRI in vitro has been defined, which furnish considerable opportunities to use the technique for the postmortem diagnosis of various diseases, to detect macroscopically undetectable changes (perifocal changes, metastases), to make a complex of intractable diagnostic problems, and to study the histological substrate of changed MR signal areas.