Comparative Assessment of Contrast Enhancement Properties of Gadolinium-Based MRI Contrast Agents

Background: Limitations of the use of gadolinium-containing radiocontrast agents, caused by the development of acute and long-term complications, stimulate the search for new, safer, and more effective forms based on gadolinium nanoparticles. Objective: comparative assessment of the magnetic contrast properties of a gadolinium nanocomposite and a gadolinium-containing diagnostic agent.

Methods: The dynamics of organ accumulation and visual MRI patterns were studied in 5 healthy female Wistar rats using a Siemens Avanto 1.5 T MRI scanner. For MRI, anesthetized animals were placed in the ventral position in a head coil; a preliminary MRI examination was performed, after which a solution of the gadolinium nanocomposite or the reference agent (Omniscan) was administered at equivalent gadolinium doses via a catheter into the lateral tail vein or into the abdominal cavity, followed by repeat MRI scanning with images acquired every 2–3 minutes. The center of the imaging region was the abdominal cavity and retroperitoneal space, with the chest included in the field of view.

Results: The comparative analysis showed that arabinogalactan-stabilized gadolinium nanoparticles possess magnetic contrast properties, evidenced by enhancement of T1-weighted images of the liver parenchyma upon intravenous administration and of the abdominal cavity upon intraperitoneal administration. Magnetic contrast imaging of the kidneys and urinary bladder was greater with Omniscan than with the gadolinium nanocomposite. However, the maximum contrast enhancement coefficient of the gadolinium nanocomposite in the liver parenchyma increased by 20% compared to baseline, whereas Omniscan administration resulted in only a 13% increase in T1-weighted signal intensity of the liver parenchyma.

Conclusion: The use of the gadolinium nanocomposite holds promise for MRI diagnostics. At this stage, it is still premature to discuss the potential clinical application of the studied gadolinium nanocomposite; a more detailed investigation of its effects on relaxation processes in both normal and pathologically altered tissues is required.