1.5 t mri scanners

All liver MRI examinations included in this study were performed by using 1.5-T MRI scanners (GE Healthcare, Milwaukee, Wis; HD, GE Healthcare). Pre-contrast sequences included axial DWI (b values: 0, 50, 150 and 500) with ADC images, axial T2-weighted images with single-shot fast spin echo (FSE) technique, gradient echo (GRE) T1-weighted out-phase and in-phase axial images and axial pre-contrast breath hold fat saturated spoiled-GRE images. Fat saturated post-contrast dynamic images were acquired in late arterial (30–40 s), portal (60–90 s), late portal (120–150 s) and delayed phases (180–210 s and at 300+ s) with breath-hold spoiled-GRE 3D technique in the axial and coronal planes. Where necessary, subtracted images were obtained from the dynamic sequences in order to aid lesion interpretation. Gadobutrol (Gadovist; Bayer Healthcare Pharmaceuticals, Whippany, NJ, United States) was the contrast agent used in all cases. A weight-based dose bolus of gadolinium contrast (0.1 mmol/kg body weight) was injected intravenously, followed by a normal saline flush (20 mL). Contrast material injection was given via a peripheral vein at 5 cc/s.