Techniques for Magnetic Particle Imaging

摘要

A magnetic particle imaging apparatus includes magnets [106,107] that produce a gradient magnetic field having a field free region (FFR), excitation field electromagnets [102,114] that produce a radiofrequency magnetic field within the field free region, high-Q receiving coils [112] that detect a response of magnetic particles in the field free region to the excitation field. Field translation electromagnets create a homogeneous magnetic field displacing the field-free region through the field of view (FOV) allowing the imaging region to be scaled to optimize scan time, scanning power, amplifier heating, SAR, dB/dt, and/or slew rate. Efficient multi-resolution scanning techniques are also provided. Intermodulated low and radio-frequency excitation signals are processed to produce an image of a distribution of the magnetic nanoparticles within the imaging region. A single composite image is computed using deconvolution of multiple signals at different harmonics.

主权项

1. A method of magnetic particle imaging, the method comprising:
placing magnetic particles into an imaging region; generating within an imaging region an inhomogeneous magnetic field having a spatial gradient and having a field-free region within the imaging region; generating within the imaging region a scanning magnetic field that displaces the position of the field-free region, wherein the scanning magnetic field causes the position of the field-free region to follow a predetermined trajectory that optimizes a property selected from the group consisting of scan time, scanning power, amplifier heating, and slew rate; generating an excitation magnetic field that excites the magnetic particles positioned at the field-free region; detecting signals produced by the magnetic particles distributed within the imaging region, wherein the signals detected at a given time are produced by magnetic particles located at positions coincident with a position of the field-free region at the given time; producing from the detected signals an image of the distribution of the magnetic particles within the imaging region.