{"title":"信号检测","authors":"Yu-Chung Norman Cheng, E. Mark Haacke","doi":"10.1002/0471142719.mib0201s13","DOIUrl":null,"url":null,"abstract":"<p>The bulk magnetization represents the equilibrium value of the magnetization when all spins have aligned themselves parallel to the main field. When this magnetization is tipped into the transverse plane, it precesses about the main field. This precession generates a changing flux through the face of an appropriately placed coil inducing an electromotive force (emf) in the coil. The measured signal is proportional to the induced emf. This unit discusses the basic physics behind detecting MR signal. The process of calculating induced emf based on Faradays law of induction is explained.</p>","PeriodicalId":100347,"journal":{"name":"Current Protocols in Magnetic Resonance Imaging","volume":"13 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2005-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/0471142719.mib0201s13","citationCount":"0","resultStr":"{\"title\":\"Signal Detection\",\"authors\":\"Yu-Chung Norman Cheng, E. Mark Haacke\",\"doi\":\"10.1002/0471142719.mib0201s13\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The bulk magnetization represents the equilibrium value of the magnetization when all spins have aligned themselves parallel to the main field. When this magnetization is tipped into the transverse plane, it precesses about the main field. This precession generates a changing flux through the face of an appropriately placed coil inducing an electromotive force (emf) in the coil. The measured signal is proportional to the induced emf. This unit discusses the basic physics behind detecting MR signal. The process of calculating induced emf based on Faradays law of induction is explained.</p>\",\"PeriodicalId\":100347,\"journal\":{\"name\":\"Current Protocols in Magnetic Resonance Imaging\",\"volume\":\"13 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2005-05-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1002/0471142719.mib0201s13\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Current Protocols in Magnetic Resonance Imaging\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/0471142719.mib0201s13\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Current Protocols in Magnetic Resonance Imaging","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/0471142719.mib0201s13","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
The bulk magnetization represents the equilibrium value of the magnetization when all spins have aligned themselves parallel to the main field. When this magnetization is tipped into the transverse plane, it precesses about the main field. This precession generates a changing flux through the face of an appropriately placed coil inducing an electromotive force (emf) in the coil. The measured signal is proportional to the induced emf. This unit discusses the basic physics behind detecting MR signal. The process of calculating induced emf based on Faradays law of induction is explained.