Gadolinium oxide- Bismuth oxide- Hydroxyapatite nanocomposite as bimodal magnetic resonance imaging/computed tomography contrast agent

Abstract

Nowadays, different non-invasive imaging modalities are used to diagnose various diseases. Each of these methods has its own advantages and limitations. Today, bimodal or multimodal imaging techniques are used to compensate these limitations. Magnetic resonance imaging (MRI) and computed tomography (CT) are effective imaging modalities, and the development of contrast agent that can be used in both MRI and CT will be useful for the diagnosis of various diseases. Nanomaterials have attracted much attention as a contrast agent due to their unique properties. Method: In this study, synthesized gadolinium oxide-bismuth oxide-hydroxyapatite nanocomposite were prepared and the nanocomposite was evaluated for its size, structural properties and toxicity. MRI and CT imaging were performed on different concentrations of these nanocomposite. For CT scans, CT numbers were plotted in different concentrations. From T1 and T2 images, curves of relaxation rates 1/T1 and 1/T2 were plotted as a function of gadolinium concentration and relaxivity values (r1 and r2) were calculated. Results: The size of the nanocomposite was 20-30 nm. The cell culture results showed high biocompatibility for the nanocomposite. The relaxivity value (r1) of the nanocomposite (33.41 mM-1s-1) was eight times higher than that of Omniscan (4.14 mM-1s-1), conventional contrast agent. With respect to the r2 of the nanocomposite (59.33 mM-1s-1), the r2/r1 ratio was calculated as 1.7, which was close to the unit. Also, the nanocomposite had higher CT numbers at similar concentrations than the conventional contrast agent, Ultravist.