| 摘要 |
Magnetic Susceptibility Imaging (MSI) comprises a means to magnetize the tissue to be imaged, such as a first Helmholtz coil, which produces a high-strength external magnetic field to which unpaired electrons of paramagnetic molecules of tissue, which includes primarily deoxyhemoglobin and oxygen, couple in a positive sense, and to which orbital electrons of diamagnetic molecules of tissue, such as proteins and water, couple in a negative sense to produce a secondary magnetic field. The imaging system further comprises a means to null the external magnetizing field, such as a second Helmholtz coil which, for example, confines the flux of both said coils to a single plane such that the component of the secondary field perpendicular to this plane is the only field with a nonzero component. The said secondary field component is detected by a detection means, such as an array of Hall voltage detectors. The detection is performed over a sample space, and the signals recorded of the said secondary field are used to reconstruct the magnetic susceptibility function of the body using the reconstruction means of the present invention, such as a Fourier Transform Algorithm.
|
