Gadolinium‐containing carbon nanomaterials for magnetic resonance imaging: Trends and challenges

Abstract

Gadolinium-containing carbon nanomaterials are a new class of contrast agent for magnetic resonance imaging. They are characterized by a superior proton relaxivity to any current commercial gadolinium contrast agent and offer the possibility to design multifunctional contrasts. Intense efforts have been made to develop these nanomaterials because of their potential for better results than the available gadolinium contrast agents. The aim of the present work is to provide a review of the advances in research on gadolinium-containing carbon nanomaterials and their advantages over conventional gadolinium contrast agents. Due to their enhanced proton relaxivity, they can provide a reliable imaging contrast for cells, tissues or organs with much smaller doses than currently used in clinical practice, thus leading to reduced toxicity (as shown by cytotoxicity and biodistribution studies). Their active targeting capability allows for improved MRI of molecular or cellular targets, overcoming the limited labelling capability of available contrast agents (restricted to physiological irregularities during pathological conditions). Their potential of multifunctionality encompasses multimodal imaging and the combination of imaging and therapy. K E Y W O R D S biodistribution, carbon nanomaterials, cell labelling, gadolinium contrast agent, magnetic resonance imaging, multifunctional contrast agent, toxicity

Can Deep Learning Replace Gadolinium in Neuro-Oncology?

“…First, contrast sequences may be entirely replaced in certain cases by zero-contrast sequences (18) such as amide proton transfer imaging (19)(20)(21), magnetic resonance spectroscopy (22), arterial spin labeling (23), or intravoxel incoherent motion imaging (24)(25)(26)(27). Second, alternative contrast agents may either compensate for lower gadolinium dosage thanks to their higher relaxivity (28)(29)(30) or eliminate completely gadolinium from their chemical composition by using manganese (31,32) or iron (33,34) instead. Third, deep learning algorithms may automatically enhance the level of contrast of low-dose MRI acquisitions (35) or predict virtual contrast-enhanced images by analyzing multiple zero-contrast sequences (36), possibly completed by a low-dose acquisition (37).…”

Role of gadolinium-based contrast agents in neurological disorders

“…Their modification with the use of biopolymers (DNA, RNA, proteins) causes them to have contrast selectivity towards cells and tissues. The potential of multifunctionality encompasses multimodal imaging and the combination of imaging and therapy [92].…”

Preparation and MRI performance of a composite contrast agent based on palygorskite pores and channels binding effect to prolong the residence time of water molecules on gadolinium ions

“…In order to increase the contrast of images of different tissues and improve the accuracy of diagnostic results, a contrast agent needs to be injected before MRI testing. 5,6 MRI contrast agents can be divided into two types, namely T1 and T2. T1 contrast agents enhance MRI signals by reducing the longitudinal relaxation time of protons in water molecules around tissues, and are also known as positive contrast agents because of their role in increasing brightness of MRI images.…”