SQUID instrumentation for early cancer diagnostics

Ultra-sensitive magnetic detection and imaging of tagged tissue cells using superparamagnetic nanoparticles is a developing technique for disease diagnosis, e.g. early cancer diagnostics. Superconducting quantum interference devices (SQUIDs) are very suitable for such sensitive measurements. Super-paramagnetic relaxometry is used for detection of targeted cells with high specificity, as only bound nanoparticles are detected via Néel relaxation. By combining relaxometry with ultra-low field magnetic resonance imaging (ULF MRI), using the same instrument, the tagged area can be imaged to provide anatomical information and bounds for the inverse problem, as the same magnetic particles work as MRI contrast agents. The combination of ULF MRI and relaxometry could provide both accurate localization and cell count of the tagged tissue, which would enable detection and localization of cancerous tissue at a very early disease stage. We describe our design of such a combined SQUID-based instrument, and present our first experimental results on phantoms.