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Magnetic resonance imaging , was born in 1973 , as a harmless, non- ionizing radiation diagnostic tool , it is not only suitable for structural imaging , functional imaging , and thus , together with the X-ray , CT , ultrasound imaging and PET become the most commonly used medical imaging techniques . Frequency source and the gradient coil is the core component in the magnetic resonance imaging system , the design of the two parts of the study . In this paper include the following : First, the introduction of the principle of magnetic resonance imaging and magnetic resonance imaging system composed . The principle section describes the basic principles of nuclear magnetic resonance , spatial coding principle . The system is part of the magnet system , the spectrometer system and computer system . Second, the gradient coil . First introduced the gradient coil design methods, including separation winding method, a distributed winding method , further matrix inversion distribution winding method , the target field , minimize magnetic energy and the stream function technique . Then discuss the eddy current , eddy current compensation technology in a magnetic resonance imaging system , including adding anti - vortex plate , pre-emphasis and self- shielded coil . Description of a small gradient coils of the bi-planar design . Third, a full-featured digital frequency source . First introduced direct digital synthesis technology , comparison with the advantages and disadvantages of traditional frequency synthesizer technology . Then gives a hardware configuration of the frequency source . As a result of the structure based on the PCI bus , the PCI bus and interface devices are introduced . Finally, the electrical performance of the test results and the application of the results of the integration of magnetic resonance imaging spectrometer .
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