Clinical safety of serial monthly administrations of gadopentetate dimeglumine in patients with multiple sclerosis: implications for natural history and early-phase treatment trials

Safety and adverse effects during 24 hours after contrast-enhanced MRI with gadobenate dimeglumine (MultiHance) in children

BACKGROUND

Gadolinium-based MR contrast agents have long been considered safe for routine diagnostic imaging. However, the advent of nephrogenic systemic fibrosis (NSF) among certain patients with severe renal insufficiency has brought the issue of safety into question. Nowhere is safety of greater concern than among children who frequently require multiple contrast-enhanced MRI examinations over an extended period of time.

OBJECTIVE

To retrospectively evaluate the safety of gadobenate dimeglumine for contrast-enhanced (CE) MRI across a range of indications.

MATERIALS AND METHODS

Two hundred pediatric inpatients (age: 4 days to 15 years) underwent CE MRI as part of clinical routine. The children received a gadobenate dimeglumine dose of either 0.05 mmol/kg body weight (liver, abdominal imaging, musculoskeletal imaging, brain and other rare indications) or 0.1 mmol/kg bodyweight (cardiovascular imaging, MR-urography). Young (< 8 years) children with congenital heart disease were intubated and underwent MRA evaluation with controlled ventilation. Monitoring for adverse events was performed for at least 24 h after each gadobenate dimeglumine injection. Depending on clinical necessity, laboratory measurements and, in some cases, vital sign and ECG determinations were made before and after contrast injection. Safety was evaluated by age group, indication and dose administered.

RESULTS

No clinically adverse events were reported among children who had one MRI scan only or among children who had several examinations. There were no changes in creatinine or bilirubin levels even in very young children.

CONCLUSIONS

No adverse events were recorded during the first 24 h following administration of gadobenate dimeglumine in 200 children.

Gadolinium-Fullerenol as a Paramagnetic Contrast Agent for Cellular Imaging

OBJECTIVES

The objectives of this study were to test cell-labeling methods to achieve intracellular labeling and T1 enhancement of cells on magnetic resonance imaging using a paramagnetic Gd@C82 fullerenol contrast agent, and to determine the effect of labeling on cell viability, metabolism, and differentiation capacity.

MATERIALS AND METHODS

We tested the use of a transfection agent for labeling cells in culture with Gd@C82 fullerenol. Proliferation, viability, and differentiation assays of mesenchymal stem cell (MSC) cultures; light and electron microscopy of MSC and macrophages; and MRI of MSC, macrophage, and HeLa cervical carcinoma cell cultures in vitro and in vivo were performed to evaluate the labeled cells.

RESULTS

Protamine sulfate transfection increased cell uptake of Gd@C82 fullerenols. The label was distributed in endosomes in the cytoplasm as shown by electron microscopy. High viability was shown for all cell lines and normal differentiation capacity was shown for MSCs. T1 of labeled MSC at 7 T was reduced 71% compared with unlabeled cells.

CONCLUSIONS

Cellular labeling with Gd@C82 is feasible and can produce T1-enhanced cells on magnetic resonance imaging. This study suggests that further investigation of Gd fullerenols for tracking studies of viable cells, including stem cells, is warranted.