Fig. (2) The couples of N20 and 1/vMCA interhemispheric ratio values, detected in each patient with CT/MRI scan unilateral transient alterations in the MCA supplied area, gathered in table 5, are displayed in the graph in descending order. All N20 and 1/vMCA interhemispheric ratio values were < 0.65 and showed significant statistic correlation (p < 0.01, r = 0.67, 95% C.I. = 0.23 to 0.88).