Scanning protocol of CE-3D-GRE
A dedicated 8-channel head coil was used on a 3.0 Tesla MRI scanner, with the 3D fast-spoiled gradient-echo sequence (SPGR) (SignaHDxt; GE Healthcare, Waukesha, WI, USA) or with the 3D fast-field echo sequence (FFE) (Ingenia CX; Philips Healthcare, Best, the Netherlands). The parameters for SPGR were as follows: TR/TE = 7.4/2.8 ms; flip angle, 20º; field of view, 20 × 20 cm; matrix size, 288 × 256; section thickness, 1.5 mm; slice spacing, 1.5 mm; and acquisition time, 110seconds. The parameters for FFE were as follows: TR/TE = 16.0/4.6 ms; flip angle, 20º; field of view, 22× 22 cm; matrix size, 448× 448; section thickness, 1.0 mm; slice spacing, 0.5 mm; and acquisition time, 218seconds. Contrast-enhanced images were acquired immediately after an intravenous bolus injection of 0.1 ml/kg gadobutrol (Gadovist 1.0; BayerSchering Pharma, Berlin, Germany) or 0.2 ml/kg megluminegadoterate (Magnescope; Guerbet,Tokyo, Japan).