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Wed, July 10, 2013
SQUIDs can be used for a new technology for ultra-sensitive magnetic detection and imaging of tissue cells marked using superparamagnetic nanoparticles. The detection limit of this technique can be as low as 10,000 cells. By comparison, state of the art spiral X-ray CT requires over 1 million cancerous cells for detection. This method consists of targeting cells using antibody labeled nanoparticles, followed by detection and imaging of the targeted area using a high-resolution SQUID-based gradiometer array. Super-paramagnetic relaxometry (SPMR) is used for detection of targeted cells with high specificity: only bound nanoparticles will be detected via Neel relaxation. The binding occurs only with cancer cells because of specific antibodies conjugated to the nanoparticle surface. By combining SPMR with ultra-low field magnetic resonance imaging (ULF MRI), using the same instrument, the targeted area can be imaged to provide anatomical information. The same magnetic particles work as MRI contrast agents. The combination of ULF MRI and SPMR provide both accurate localization and cell count of the targeted tissue. This approach provides a robust diagnostic tool for the detection and localization of cancerous tissue targeted with magnetic markers at a very early disease stage. ULF MRI and SPMR measurements have never been combined before in a single device. We will describe our design of such a combined SQUID-based instrument, and present our first experimental results of combined SPMR and ULF MRI on phantoms.
SQUID Instrumentation for Early Cancer Diagnostics