In vivo magnetic particle imaging: angiography of inferior vena cava and aorta in rats using newly developed multicore particles

Abstract

Magnetic Particle Imaging (MPI) is a new imaging modality, which maps the distribution of magnetic nanoparticles (MNP) in 3D with high temporal resolution. It thus may be suited for cardiovascular imaging. Its sensitivity and spatial resolution critically depend on the magnetic properties of MNP. Therefore, we used novel multicore nanoparticles (MCP 3) for in-vivo MPI in rats and analyzed dose requirements, sensitivity and detail resolution. 8 rats were examined using a preclinical MPI scanner (Bruker Biospin GmbH, Germany) equipped with a separate receive coil. MCP 3 and Resovist were administered intravenously (i.v.) into the rats’ tail veins at doses of 0.1, 0.05 and 0.025 mmol Fe/kg followed by serial MPI acquisition with a temporal resolution of 46 volumes per second. Based on a qualitative visual scoring system MCP 3–MPI images showed a significantly (P ≤ 0.05) higher image quality than Resovist-MPI images. Morphological features such as vessel lumen diameters (DL) of the inferior vena cava (IVC) and abdominal aorta (AA) could be assessed along a 2-cm segment in mesenteric area only after administration of MCP 3 at dosages of 0.1, 0.05 mmol Fe/kg. The mean DL ± SD estimated was 2.7 ± 0.6 mm for IVC and 2.4 ± 0.7 mm for AA. Evaluation of DL of the IVC and AA was not possible in Resovist-MPI images. Our results show, that MCP 3 provide better image quality at a lower dosage than Resovist. MCP 3-MPI with a clinically acceptable dose of 0.05 mmol Fe/kg increased the visibility of vessel lumens compared to Resovist-based MPI towards possible detection of vascular abnormalities such as stenosis or aneurysms, in vivo.

Magnetic particle imaging: tracer development and the biomedical applications of a radiation-free, sensitive, and quantitative imaging modality

“…In a similar study, Mohtashamdolatshahi et al compared the in vivo imaging quality of angiographic MPI for newly developed multi-core particles (MCP 3), 207 and Resovist, in the inferior vena cava and aorta. 347 The tracers were administered intravenously into the tail veins of rat models at doses of 0.1, 348 This study was performed in the inferior vena cava of healthy FVB mice, and the images obtained with MPI were compared with those from MRI. Analysis revealed good agreement between the in vivo velocities, with MRI at 4.0 ± 1.5 cm/s and MPI at 4.8 ± 1.1 cm/s.…”

“…In a similar study, Mohtashamdolatshahi et al compared the in vivo imaging quality of angiographic MPI for newly developed multi-core particles (MCP 3), 206 and Resovist, in the inferior vena cava and aorta. 346 The tracers were administered intravenously into the tail veins of rat models at doses of 0.1, 0.05 and 0.025 mmol Fe kg −1 . This was followed by serial MPI acquisition using a commercial MPI system.…”

Magnetic Particle Imaging: Current and Future Applications, Magnetic Nanoparticle Synthesis Methods and Safety Measures

“…Mohtashamdolatshahi et al [62] synthesized a novel multicore nanoparticle for direct comparison against commercial contrast agent, Resovist. The multicore particles provided significantly higher resolution at a lower dose than Resovist.…”

Tailored Magnetic Multicore Nanoparticles for Use as Blood Pool MPI Tracers

“…Monodispersity, which is crucial for a good MPI performance, is achieved by fractional magnetic separation and the very good magnetic properties, by an annealing process [9,23,24]. In MCPs, small single crystallite cores are combined to form larger nanoparticles, which have already shown very good MPI tracer performance along with excellent in vivo behavior in rats [25][26][27][28]. MCPs are coated with carboxymethyl dextran (CMD) and therefore negatively charged at physiological pH.…”