Utilità della risonanza magnetica perfusionale nella diagnosi differenziale tra lesioni demielinizzanti e patologia multinfartuale

Abstract

20 pts affected by chronic cerebrovascular disease (10) and demyelinating disease (10) were studied by means of conventional MRI and T2*-w dynamic scans (6 slices acquired in 2“, 60 dynamic scans obtained for each slice, total acquisition time ?120”) with the aim of evaluating wether different patterns could be defined between infarctions and demyelinations. 5 subjects were excluded for different reasons. Signal intensity (SI) and transit time (BPAT = Bolus Peak Arrival Time) values were calculated from ROIs positioned on affected and contralateral non affected areas in each pt. In the group affected by demyelinating diseases, data from pathological ROIs were not significantly different from the contralateral, although the basal value of the lesions started from more elevated levels. On the contrary, pts affected by vascular lesions showed significantly different values of SI between pathological ROIs and apparently normal contralateral brain (χ2 test, p<0.001). In two cases, asymmetry of the BPAT due to extracranial carotid stenosis were recorded. In conclusion, our experience encourages the use of perfusional studies with the aim of characterizing pathological processes. The difference recorded between the two groups could suggest wider use of the technique when differential diagnosis between the two pathological entities is not simply obtainable by standard MRI (i.e.: Multiple Sclerosis vs. autoimmune vasculitides). The limited number of patients enrolled in this study makes our results to be considered non definitive, although encouraging.