• Liver
• LAVA
• High Field
• Gd-EOB-DTPA
• Enhancement Ratio
• Dynamic study

Objectives:
to determine whether a fast injection rate (3mL/s) of Gd-EOB-DTPA affects livers Enhancement Ratios (ERs), Signal to Noise Ratio (SNR), and MR image quality, in comparison to a slow injection rate (1.5 mL/s), in cirrhotic patients submitted to 1.5T and 3.0T MRI.
Materials and methods:
249 consecutive, cirrhotic patients were submitted to MR studies. On the basis of magnetic field strength (1.5T vs 3T) and contrast injection flow rate (1.5ml/sec vs 3ml/sec), patients were divided into four groups: Group I: 77 patients (1.5T and 1.5ml/s); Group II: 89 patients (1.5T and 3mL/s; Group III: 34 patients (3.0T and 1.5mL/s); Group IV: 49 patients (3.0T and 3mL/s).
Contrast administration was obtained by means of an automatic injector; in all studies, two arterial phases (early arterial and parenchymal arterial phases) were acquired, by means of a pre-definite, fixed scan delay method.
For each arterial phase, ERs of liver parenchymas and abdominal aortic lumen, and SNR were calculated. A qualitative analysis of Gibbs artifacts on both arterial phases was also performed.
Results:
Contrast injection rate resulted not to influence ERs of liver parenchymas on early arterial nor on parenchymal arterial phases (p 0.9573 and p: 0.0308 respectively), nor ERs of aortic lumens on both arterial phases, nor ERs of other target structures, nor SNR of liver parenchymas on both arterial phase, nor the incidence of artifacts.
Magnetic field strength instead affects SNR of liver parenchymas on both arterial phases.
Conclusions:
On the basis of our study protocol, contrast injection rate does not influence ERs of liver parenchymas on arterial phases, independently from magnetic field strenght. Dedicated and optimized dynamic sequences might limited artifacts, independently from contrast injection flow rate.