Utility of dual-energy CT for predicting the vascularity of meningiomas

Purpose: Dual-energy computed tomography (DECT) can provide iodine, electron density (ED), and effective atomic number Z (Z(eff)) maps, facilitating the identification of tissue types. We investigated whether DECT parameters can predict the vascularity of meningiomas. Method: We acquired DECT and perfusion CT (PCT) images in 24 patients with histologically diagnosed meningioma. Regions of interest (ROIs) were placed M the tumor in iodine, ED, and Z(eff) maps derived from DECT and in a blood volume (BV) map derived from PCT. To normalize these parameters' values, we divided them by the values of contralateral normal-appearing white matter, i.e., the relative (r)ED, rZ(eff), and rBV. The vascular density of the tumor specimens was immunohistochemically analyzed by calculating the von Willebrand factor-positive vessel wall. We calculated Pearson's correlation coefficients to determine the correlation with PCT/DECT parameters and an immunohistopathological index. Results: Contrast rZ(eff) (r = 0.7020, p = 0.0001) and iodine (r = 0.5814, p = 0.0029) both had positive correlations with rBV derived from PCT. The rED values were negatively correlated with the rBV values (r = -0.4735, p = 0.0194), and the vascular density results confirmed positive correlations with rBV (r = 0.6909, p = 0.0002) and contrast rZ(eff) (r = 0.4982, p = 0.0132) and a negative correlation with rED (r = -0.4265, p = 0.0377). Regarding the radiation exposure, the mean estimated volume CT dose index (CTDIvol) of DECT was 33.1 +/- 1.72 mGy, much lower than that of PCT (103.3 +/- 4.65 mGy). Conclusions: DECT predicted vascular density with lower radiation exposure compared to PCT. DECT could potentially replace PCT for evaluating the vascularity of meningiomas.