Viscoelastic ultrasound images of tissues by tracking the movement of magnetic nanoparticles

• Grant number: 10/15825-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2011
• End date: December 31, 2011
• Field of knowledge: Engineering - Biomedical Engineering - Medical Engineering
• Principal Investigator: Dimas Tadeu Covas
• Grantee: Theo Zeferino Pavan
• Host Institution: Hemocentro de Ribeirão Preto. Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da USP (HCMRP). Secretaria da Saúde (São Paulo - Estado). Ribeirão Preto , SP, Brazil
• Associated research grant: 98/14247-6 - Center for Research on Cell-Based Therapy, AP.CEPID

Abstract

Magnetic and ultrasound methodologies will be used to map the viscoelastic parameters of a medium containing magnetic nanoparticles. To achieve this goal the nanoparticles will be excited by magnetic non contact force and the resulting movement will be tracked through ultrasonic techniques. To identify only the regions containing the nanoparticles a dedicated elastographic algorithm will be used. The expected result is an image of a biological magnetically labeled tissue representing the induced vibration displacement or velocity map of the nanoparticles. Through this displacement map, viscoelastic parameters of the medium being investigated will be inferred. The magnetic field is applied through a coil attached the ultrasound transducer generating a magnetic field gradient in the region of interest. Besides being a new way of imaging the viscoelastic parameters of tissues this methodology can be considered as a new dynamic medical image modality. These images are capable of monitoring functional activities of internal regions of the body. In this case the magnetic nanoparticles can be labeled with molecules having affinity to specific organs or cellular receptors. Drug targeting employing nanoparticles as drug carrier is an alternative to improve drug delivering, in the case of magnetic nanoparticles, the use of magnetic excitation and ultrasound detection could be an option to monitoring the drug delivering. (AU)