[Estimation of brain tissue in schizophrenic patients using magnetization transfer imaging--preliminary report]

Volumetric loss of some cerebral structures is noticed during morphometrical investigations, and it is one of the most frequent abnormalities in schizophrenic patients' brains. The new methods of MRI investigations show subtle changes in cerebral white matter, which are undetectable by standard MRI. The magnetic transfer imaging (MTI) may be used to estimate the structural integrity of white matter and allows for visualisation of minimal changes in cerebral tissue.

The aim of this work was to estimate the cerebral tissue using magnetic transfer imaging and the analysis of magnetic transfer ratio (MTR) maps in schizophrenic patients.

We examined 15 patients with schizophrenia and 15 healthy volunteers. We used sequences of: SE, FLAIR and GE with- and without saturation pulse, acquiring standard T1- and T2-weighted anatomical images and images with magnetic transfer effect and without it. For quantitative estimation of magnetic transfer, the MTR-maps were calculated from a standard formula: MTR=Mo-Ms/Mo'l00%, and the obtained MTR-values, from regions of interest in schizophrenics were compared with MTR-values in healthy persons.

Both, in the schizophrenic group and in the controls, MTR-values (from the analysed regions of white matter) were between 30-50%. We observed a statistically significant reduction of MTR of schizophrenic patients in the white matter of the left temporal and left frontal lobes.

With the help of the technique and methods of statistical analysis, the identification of altered MTR-areas in patients with schizophrenia is possible. The results confirm the presence of areas of minimal injuries in schizophrenic persons' brain tissue, which are detectable using magnetic transfer imaging.