Perfusion Showdown: Comparison of Multiple MRI Perfusion Techniques in the Grading of Pediatric Brain Tumors

BACKGROUND AND PURPOSE: There are multiple MRI perfusion techniques, with limited available literature comparing these techniques in the grading of pediatric brain tumors. For efficiency and limiting scan time, ideally only one MRI perfusion technique can be used in initial imaging. We compared DSC, DCE, and IVIM along with ADC from DWI for differentiating high versus low grade pediatric brain tumors.

MATERIALS AND METHODS: Presurgical MRI at a single pediatric hospital for primary brain tumor of glial, neuronal or embryonal origin including DWI, DSC, DCE, and IVIM with postsurgical histopathology results with WHO tumor grading were included. Tumor VOI was drawn on T2 weighted images registered to selected parametric maps from DWI, DSC, DCE and IVIM. Multiple Bonferroni corrected t-tests were performed on the mean tumor values for each selected parameter, including histogram analysis of 95th percentile rCBV, 5th percentile ADC and 5th percentile D, to evaluate for significance between high-and low-grade tumors. ROC analysis was performed for significant t-test results.

RESULTS: 72 subjects were included with 36 low grade and 36 high grade tumors. T-test after Bonferroni correction yielded significant results for 5th percentile ADC (p=0.003), mean ADC (p=0.006), mean D (p=0.009), and 5th percentile D (p=0.02). Specifically, 95th percentile rCBV, mean rCBV, D*, f, and all DCE parameters were not significant for high vs low grade pediatric brain tumors after correction. Only mean rCBV was significant before but not after Bonferroni correction (p=0.04 → p=0.35).

ROC analysis for the parameters with t-test significance before and after Bonferroni correction had the following AUC in descending order: 5th percentile ADC (0.791, 0.68-0.88, p<0.001), 5th percentile D (0.789, 0.68-0.88, p<0.001), mean D (0.76, 0.64-0.85, p<0.001), mean ADC (0.754,0.64-0.85, p<0.001) and mean rCBV (0.683, 0.56-0.79, p=0.004).

CONCLUSIONS: Perfusion parameters from IVIM, DCE, DSC were not able to significantly differentiate between high versus low grade pediatric brain tumors compared to ADC in our study. 5^th percentile ADC had the best performance and can be the primary technique for grading pediatric brain tumors.

ABBREVIATIONS: ADC = Apparent Diffusion Coefficient, DCE = Dynamic Contrast Enhancement, DSC = Dynamic Susceptibility Artifact, DWI = Diffusion Weighted Imaging, IVIM = Intravoxel Incoherent Motion, VOI = Voxel of Interest