Pre-clinical development of contrast-enhanced magneto-motive ultrasound imaging of lymph nodes

A new approach for the detection and characterisation of lymph nodes (LN) for colorectal cancer staging has been implemented in this study. Contrast Enhanced Magnetomotive Ultrasound (CE-MMUS) is aiming to combine CEUS and MMUS using Magnetic NanoParticles(MNP)-microbubbles for improved differentiation of tissues and LNs. Biotinylated MNPs were administered to the left hock of a mouse 24 hours prior to imaging and the targeted microbubbles were administered intravenously immediately before imaging. MMUS and CE-MMUS imaging were performed using Vevo 3100 preclinical ultrasound scanner (VisualSonics) with a 40 MHz transducer (MX550D). Acquisitions of IQ mode images were exported for post-processing in Matlab to reveal the mean (rms) tissue displacement in each LN interrogated. A slight increase in tissue displacement (0.5±0.07 μm) with the addition of MBs compared to MNPs alone. A maximum of 0.78 ±0.05 μm mean displacement was recorded post mortem. Furthermore, a Colorectal Cancer (CCR) Model was examined providing information about the distribution of the magnetic contrast agent within the lymph nodes which relates to perfusion and lymphatic drainage in both the control (healthy) and the diseased (tumour induced) lymph node.