Whole-tumor histogram analysis of DWI and QSI for differentiating between meningioma and schwannoma: a pilot study

Purpose To investigate whether whole-tumor histogram analyses of diffusivity measurements derived from q-space imaging (QSI) improves the differentiation between meningioma and schwannoma. Materials and methods Fifteen extra-axial tumors (11 meningiomas and 4 schwannomas) with MR examinations from April 2011 to May 2013 were included. Three-dimensional regions of interest (ROI) encompassed the whole tumor, including cystic areas. Histogram analyses of mean displacement (MD) derived from QSI and apparent diffusion coefficient (ADC) for the ROI were performed at mean, the five percentiles of MD n and ADC n ( n = 5, 25, 50, 75, 95th), kurtosis, and skewness. To determine the diagnostic ability of MD n and ADC n , we also compared the area under the curve (AUC) on receiver operating characteristic (ROC) analysis. Results Histogram analyses revealed significant differences between meningioma and schwannoma in MD 75 , ADC 25 , ADC 50 , ADC 75 , and kurtosis of ADC. The ROC analysis of kurtosis of ADC and MD 75 resulted in an AUC of 1.0 and 0.96, respectively. There were no significant differences between the AUC of MD 75 and that of kurtosis of ADC ( p = 0.41). Conclusion The histogram analyses of MD and ADC derived from QSI were both equally useful in differentiating between intracranial meningioma and schwannoma.