Diagnostic Accuracy of Dynamic Contrast-Enhanced MR Imaging Using a Phase-Derived Vascular Input Function in the Preoperative Grading of Gliomas

BACKGROUND AND PURPOSE: The accuracy of tumor plasma volume and K-trans estimates obtained with DCE MR imaging may have inaccuracies introduced by a poor estimation of the VIF. In this study, we evaluated the diagnostic accuracy of a novel technique by using a phase-derived VIE and "bookend" T1 measurements in the preoperative grading of patients with suspected gliomas. MATERIALS AND METHODS: This prospective study included 46 patients with a new pathologically confirmed diagnosis of gnome. Both magnitude and phase images were acquired during DCE MR imaging for estimates of K-trans_phi and V-p_phi (calculated from a phase-derived VIF and bookend T1 measurements) as well as K-trans_SI and V-p_SI (calculated from a magnitude-derived VIF without T1 measurements). RESULTS: Median K-trans_phi values were 0.0041 minutes(-1) (95% CI, 0.00062-0.033), 0.031 minutes(-1) (0.011-0.150), and 0.088 minutes(-1) (0.069-0.110) for grade II, III, and IV gliomas, respectively (P <= .05 for each). Median V-p_phi values were 0.64 mL/100 g (0.06-1.40), 0.98 mL/100 g (0.34-2.20), and 2.16 mL/100 g (1.8-3.1) with P = .15 between grade II and III gliomas and P = .015 between grade III and IV gliomas. In differentiating low-grade from high-grade gliomas, AUCs for K-trans_phi, V-p_phi K-trans_SI, and V-p_SI were 0.87 (0.73-1), 0.84 (0.69-0.98), 0.81 (0.59.1), and 0.84 (0.66-0.91). The differences between the AUCs were not statistically significant. CONCLUSIONS: K-trans_phi and V-p_phi are parameters that can help in differentiating low-grade from high-grade gliomas.