Gadolinium-enhanced phase-contrast magnetic resonance portography

Purpose: The purpose of this study was to investigate the effect and usefulness of gadolinium-chelated contrast medium in phase-contrast magnetic resonance (MR) portography. Methods: Twenty-six patients (21 men, 5 women; aged 34 to 79 years, mean 62 years) underwent respiratory-triggered 3-dimensional phase-contrast portography before and after administration of gadolinium in a 1.5T MR unit. Coronal maximum intensity projection (MIP) images of the portal vein were reconstructed and compared to conventional arterial portograms regarding visualization. Signal-to-noise ratio (SNR) and portal vein-to-liver contrast-to-noise ratios (CNR) of main, right, right anterior, right posterior, left portal veins, and umbilical portion were measured on both non-enhanced and gadolinium-enhanced images and compared. Results: Portal veins and branches were more clearly visualized on the gadolinium-enhanced than on the non-enhanced images. Compared to arterial portography, gadolinium-enhanced portography showed similar performances in visualization, except in the right posterior branch and left portal vein. No severe image degradation from respiration was experienced. SNR was significantly higher on the gadolinium-enhanced than on non-enhanced images except in the right anterior branch. CNR was significantly higher on the gadolinium-enhanced than on the non-enhanced images at all measured locations. Conclusions: Administration of gadolinium improves the SNR and CNR of phase-contrast portography and visualization of the portal vein. The phase-contrast technique with gadolinium enhancement can be used to evaluate the portal vein as a supplemental technique.