Measurement of the Iron Oxide and Gadolinium Based Contrast Agent Relaxation Properties in the Presence of the Saline and Glucose Molecules during Low-Field MRI

The contrast agents are usually used in clinical practice for the enhanced contrast imaging of the human tissue. They are iron oxides or gadolinium based nanoparticles in a carrier fluid. In a previous study we have found, that the elevated levels of the human metabolites can change the relaxation properties of the magnetite nanoparticles during 4.7 T MRI. Therefore the aim of this paper is to find out if the different concentration levels of the saline and glucose molecules, which are typical for the several pathological processes, can change the relaxation properties of these contrast agents during low-field MRI (0.178). We have found that physiological concentration of the saline and glucose molecules have little, but not negligible influence to the signal intensity for different concentration of the contrast agent (maximum ≈ 30% in comparison with water). The different concentration of the saline and glucose molecules alters the signal intensity for the selected pulse sequence and contrast agent concentration in a similar way, with maximum intensity change up to 17%. Such changes are hardly visible to the naked eye in low-field MRI, however they can have influence to the post-processed data analysis, e.g. in relaxation time comparison. Definitely, these findings should be verified in standard high-field MRI tomographs 1.5 and 3 T, before final conclusions.