| 摘要 |
A magnetic resonance imaging system has an elongate hand-held probe with a permanent magnet positioned within the probe to align the pole axis of the permanent magnet with the central axis of the probe. A burst/sense electromagnetic coil is positioned to provide a magnetic field coaxial with that of the permanent magnet. The burst/sense coil provides high frequency bursts to excite nuclei in a sample with the end of the probe held proximate a surface of the sample. Bursts are alternated with sensing periods to sense echo from resonating nuclei in the sample. The sensed point in a sample volume can be moved by altering the burst frequency. In another aspect a bias field is provided by the burst/sense coil, and deflection coils are used to move the sensed point through a slice by deflecting the summed permanent and bias field. Different slices are sensed by changing the bias field and repeating sensing an array of points in a new slice. The probe is integrated with a general-purpose computer to provide control, recording of sensed values, assembly of bit maps, and display of images.
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