Hepatic MR imaging: comparison of 2D and 3D gradient echo techniques.

Abstract

To compare fat-suppressed three-dimensional gradient echo (3D-GRE) and two-dimensional gradient echo (2D-GRE) techniques for hepatic magnetic resonance imaging. For 107 patients with suspected focal hepatic lesions, unenhanced 2D-GRE multislice in-phase and opposed-phase images and 3D-GRE images were obtained. Two radiologists independently and in random order reviewed the images. Quantitative analysis compared contrast-to-noise ratio (C/N) of liver masses and of the liver to spleen and signal-to-noise ratio (S/N) of the liver. Subjective grading of lesion conspicuity, confidence for lesion detection, artifacts, and overall image quality were also evaluated. Conspicuity and confidence for focal lesions was statistically significantly higher on 3D-GRE than on 2D-GRE images. Liver-to-spleen C/N was higher on 3D-GRE images than on in-phase and opposed-phase 2D-GRE images (p < 0.01). Liver S/N was higher on in-phase 2D-GRE images than on 3D-GRE and opposed-phase 2D-GRE images (p < 0.001). Lesion-to-liver C/N was higher on 3D-GRE images than on 2D-GRE images for nonsolid lesions (p < 0.05), but there was no significant difference for solid lesions. Motion and pulsation artifacts were significantly fewer on 3D-GRE images, but graininess and shading were significantly higher. Overall image quality was not significantly different for the three sequences. Fat-suppressed 3D-GRE sequences can afford comparable or better image quality than 2D-GRE images and may have the potential to detect more focal hepatic lesions.