Pulsed magnetic particle imaging systems and methods

A method of imaging an object using a magnetic nanoparticle tracer;

• comprising:
• providing said object with said magnetic nanoparticle tracer;
• applying a spatially structured magnetic field that has a field-free region (FFR) such that said FFR and surrounding regions of said spatially structured magnetic field intercept said object under observation at a region containing at least a portion of said magnetic nanoparticle tracer;
• exciting a portion of said magnetic nanoparticle tracer by using an excitation waveform to change at least one of a property of said FFR or a position of said FFR;
• detecting changes in magnetization of said magnetic nanoparticle tracer resulting from said exciting while said property of said FFR and said position of said FFR are substantially constant to obtain a detection signal;
• repeating said exciting and detecting for a plurality of different locations of said FFR within said object to obtain a plurality of detection signals;
• and
• processing said plurality of detections signals to render an image of a region of said object,
• wherein said excitation waveform comprises a magnetization preparation portion and a readout portion, said magnetization preparation portion comprising at least a fraction of said transient portion, and said readout portion comprising at least a fraction of said constant portion.

A device for use with or as a part of a pulsed magnetic particle imaging system, comprising:

• a pulsed excitation system arranged proximate a sample observation region, said pulsed excitation system comprising an electromagnet and a pulse sequence generator electrically connected to said electromagnet to provide an excitation waveform to said electromagnet, wherein said electromagnet provides a magnetic field within said sample observation region to generate an excitation signal from a sample when held by said sample holder in said sample observation region;
• and
• a detection system arranged proximate said sample observation region, said detection system being configured to detect said excitation signal from said sample to provide a detection signal,
• wherein said excitation waveform comprises a transient portion and a substantially constant portion, and
• wherein said excitation waveform comprises a magnetization preparation portion and a readout portion, said magnetization preparation portion comprising at least a fraction of said transient portion, and said readout portion comprising at least a fraction of said constant portion.