Pediatric astrocytic tumor grading : comparison between arterial spin labeling and dynamic susceptibility contrast MRI perfusion

PURPOSE: The aim of this study was to compare arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) MRI perfusion with respect to diagnostic performance in tumor grading in pediatric patients with low- and high-grade astrocytic tumors (AT). METHODS: We retrospectively analyzed 37 children with histologically proven treatment naive low- and high-grade AT who underwent concomitant pre-operative ASL and DSC MRI perfusion. Studies were performed on a 1.5 T scanner, and a pulsed technique was used for ASL. DSC data were post-processed with a leakage correction software. Normalization of tumor perfusion parameters was performed with contralateral normal appearing gray matter. Normalized cerebral blood volume (nCBV) values in the most perfused area of each neoplasm were compared with normalized DSC-derived cerebral blood flow (nDSC-CBF) and ASL-derived cerebral blood flow (nASL-CBF) data, and correlated with WHO tumor grade. Statistics included Pearson's chi-square and Mann-Whitney U tests, Spearman's rank correlation, and receiver operating characteristic (ROC) analysis. RESULTS: A significant correlation was demonstrated between DSC and ASL data (p < 0.001). Significant differences in terms of DSC and ASL data were found between low- and high-grade AT (p < 0.001). ROC analysis demonstrated similar performances between all parameters in predicting tumor grade (nCBV: AUC 0.96, p < 0.001; nDSC-CBF: AUC 0.98, p < 0.001; nASL-CBF: AUC 0.96, p < 0.001). CONCLUSIONS: Normalized pulsed ASL performed with a 1.5 T scanner provides comparable results to DSC MRI perfusion in pediatric AT and may allow distinction between high- and low-grade AT