Not only manganese, but fruit component effects dictate the efficiency of fruit juice as an oral magnetic resonance imaging contrast agent

Abstract

Proteins JOYNLABSeveral fruit juices are used as oral contrast agents to improve the quality of images in magnetic resonance cholangiopancreatography. They are often preferred to conventional synthetic contrast agents because of their very low cost, natural origin, intrinsic safety, and comparable image qualities. Pineapple and blueberry juices are the most employed in clinical practice due to their higher content of manganese(II) ions. The interest of pharmaceutical companies in these products is testified by the appearance in the market of fruit juice derivatives with improved contrast efficacy.Here, we investigate the origin of the contrast of blueberry juice, analyze the parameters that can effect it, and elucidate the differences with pineapple juice and manganese(II) solutions. It appears that, although manganese(II) is the paramagnetic ion responsible for the contrast, it is the interaction of manganese(II) with other juice components that modulates the efficiency of the juice as a magnetic resonance contrast agent. On these grounds, we conclude that blueberry juice concentrated to the same manganese concentration of pineapple juice would prove a more efficient contrast agent than pineapple juice.

Large Protein Assemblies for High-Relaxivity Contrast Agents: The Case of Gadolinium-Labeled Asparaginase

“…The strategy to reduce the risks associated with the administration of contrast agents without reducing the quality, and thus the diagnostic accuracy, of the MRI images, passes through the use of molecules not containing gadolinium­(III) ions but similarly able to enhance the nuclear relaxation rates of water protons, − or through the development of gadolinium complexes with higher efficiency so that the injected dose can be sizably reduced. A reduction of the injected gadolinium­(III) dose can be achieved (i) by targeting the contrast agents to specifically accumulate them in the tissues of interest and (ii) by increasing the capability of the agents to enhance the water proton relaxation rates.…”