SENSOR FOR DETECTION OF MAGNETIC PARTICLES

Disclosed is a magnetic sensor for measuring flux density. The sensor comprises at least one tunnelling magnetoresistor, supporting circuitry and an output for outputting a signal from the tunnelling magnetoresistor. In another aspect, there is also provided a sensor probe comprising at least one magnetic sensor. A magnetic probe system is also described, comprising the probe sensor and processing circuitry. Methods of processing the output signal from the magnetic sensor are also described. In one application, the system and method allow for detection of tissue such as lymph nodes that have taken up small quantities of magnetic particles upon injection of a magnetic tracer containing the magnetic particles into a patient, and can be used to identify such tissue that could be affected by certain forms of cancer.