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 VIF 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 glioma. Both magnitude and phase images were acquired during DCE MR imaging for estimates of K^trans_ϕ and V_{p_}ϕ (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_ϕ 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_}ϕ 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_ϕ, V_{p_}ϕ, 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_ϕ and V_{p_}ϕ are parameters that can help in differentiating low-grade from high-grade gliomas.