Session Item

In the panorama of advanced magnetic resonance imaging (MRI) techniques, Diffusion Weighted Imaging (DWI) proved to be a valuable diagnostic tool in the neuro-oncologic  field: a recent development of Diffusion Imaging is represented by the Intravoxel Incoherent Motion technique (IVIM) which allows to study,in a more specific way, the diffusivity of the tissues of an organism, also  taking into account their vascular micro-perfusivity.The following work carried out aims  to verify through the processing of data obtained from imaging techniques DWI-MRI and IVIM-MRI to detect early changes in diffusion, preudo-diffusion and perfusion properties of normal tissue in patients affected by meningioma.

Quantitative data set related to the diffusiveness of the healthy white matter (WM) of ten patients suffering from anaplastic meningioma treated with Protontherapy before the start of treatment and in the follow-up at 3, 6 and 9 months after the end of the treatment were analysed.
The data were collected in post-processing using a specific software from multiparametric maps (ADC, D, D* and f) in turn extrapolated from DWI-MRI sequences, obtaining for each patient the total number of WM voxels contoured, the total volume included in the contours (mm³) and the average intensity of voxels with the relative standard deviation DS (σ).

The results obtained concerning the mean intensity values (mm²/s) of ADC, D, D* and f show a homogeneous trend both in comparison of these for each patient and among the ten patients examined, with small discrepancies between them: ADC= 0,79x10-3 mm²/s (±150,3628 mm²/s); D= 0,70×10−3 mm²/s (±159,0189mm²/s); D*= 1,3×102 mm²/s (±0,0335 mm²/s); f= 1,1x10 mm²/s (±0,1052 mm²/s). D is similar to ADC, but it's larger as it takes into account, as a loss contribution to the signal , not only perfusion but also the effect of diffusion; D*, as a result of microperfusion in capillaries is shown to be greater than D. D* as well as f, due to the inability of the MRI scanner to acquire images at low b-values (0-50 s/mm²), where micro-perfusion gives a greater contribution to signal loss than diffusion, could provide less accurate data than desirable.

In conclusion, it was observed that the ADC value obtained from DWI sequences is (0.79x10-3 mm²/s) in line with the expected values in the literature of neuro-oncological studies (0,319–1,05×10−3mm²/s).  In ight of these considerations, it is to be hoped that DWI-MRI and IVIM-MRI techniques, which are so promising in the MRI approach, will contribute more and more to diagnostic improvement, both in the field of research and clinics.