Despite this disadvantage, ASL estimates of CBF appeared to be of

Despite this disadvantage, ASL estimates of CBF appeared to be of sufficient quality to localize regions of highest vascularity when compared with DSC. A statistically significant, positive linear correlation was observed between ASL and DSC estimates of mean normalized CBF within both FLAIR hyperintense (Pearson’s correlation coefficient, R2 = .706, P < .0001) and contrast-enhancing regions (Pearson's correlation coefficient, R2 = .809, P < .0001) on a per patient basis (Figs 2A, B). The GSK-3 beta pathway linear slope that best explained the correlation between normalized

ASL and DSC estimates of CBF in all tumors was .72 ± .04 standard error of the mean (SEM) for FLAIR hyperintense and .68 ± .03 SEM for contrast-enhancing PR-171 supplier regions, suggesting DSC had about a 3:1 higher dynamic range of CBF measurements

compared to ASL. Similarly for glioblastoma patients, a statistically significant linear was observed in FLAIR (Pearson’s correlation coefficient, R2 = .829, P < .0001) and contrast-enhancing regions (Pearson's correlation coefficient, R2 = .872, P < .0001). The linear relationship between ASL and DSC estimates of CBF in glioblastomas was similar to that of all tumors, measuring .74 ± .05 SEM for FLAIR and .66 ± .04 SEM for contrast-enhancing regions. These results suggest overall estimates of tumor blood flow may be similar between the two techniques, albeit to a different level of sensitivity and dynamic range. Surprisingly, only a minority of patients examined in the current study demonstrated a statistically significant linear correlation between DSC and ASL measurements of relative CBF on a voxel-wise basis for areas of FLAIR and contrast-enhanced regions. As illustrated in Figure

3A, some patients did illustrate a strong voxel-wise association 上海皓元医药股份有限公司 between the two measurements of CBF, specifically showing a 2:1 correspondence (slope ∼.5) between DSC and ASL DSC. The vast majority of patients, however, had voxel-wise relationships similar to those illustrated in Figure 3B, where no apparent linear relationship was evident. Approximately 31% of glioblastoma patients (4 of 13) demonstrated a significant voxel-wise linear correlation between DSC and ASL measurements of CBF with FLAIR hyperintense regions and only 38% of glioblastoma patients (5 of 13) showed a significant correlation in contrast-enhancing regions (Chi-Squared Goodness of Fit, χ2red > 1.0, P < .05). Interestingly, both patients with anaplastic astrocytoma (WHO III) had a significant voxel-wise correlation between DSC and ASL measurements of CBF in both FLAIR and postcontrast regions of interest (Chi-Squared Goodness of Fit, χ2red > 1.0, P < .05).

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