Non-contrast-enhanced MR portography and hepatic venography with time-spatial labeling inversion pulses: comparison at 1.5 Tesla and 3 Tesla

摘要

A 3 Tesla (3?T) magnetic resonance (MR) scanner is a promising tool for upper abdominal MR angiography. However, there is no report focused on the image quality of non-contrast-enhanced MR portography and hepatic venography at 3?T. To compare and evaluate images of non-contrast-enhanced MR portography and hepatic venography with time-spatial labeling inversion pulses (Time-SLIP) at 1.5 Tesla (1.5?T) and 3?T. Twenty-five healthy volunteers were examined using respiratory-triggered three-dimensional balanced steady-state free-precession (bSSFP) with Time-SLIP. For portography, we used one tagging pulse (selective inversion recovery) and one non-selective inversion recovery pulse; for venography, two tagging pulses were used. The relative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were quantified, and the quality of visualization was evaluated. The CNRs of the main portal vein, right portal vein, and left portal vein at 3?T were better than at 1.5?T. The image quality scores for the portal branches of segment 4, 5, and 8 were significantly higher at 3?T than at 1.5?T. The CNR of the right hepatic vein (RHV) at 3?T was significantly lower than at 1.5?T. The image quality scores of RHV and the middle hepatic vein were higher at 1.5?T than at 3?T. For RHV visualization, the difference was statistically significant. Non-contrast-enhanced MR portography with Time-SLIP at 3?T significantly improved visualization of the peripheral branch in healthy volunteers compared with1.5?T. Non-contrast-enhanced MR hepatic venography at 1.5?T was better than at 3?T.