Introduction to Magnetic Resonance Imaging
نویسندگان
چکیده
2 Introduction 2 2.1 Signal Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1.1 The B0 field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1.2 The B1 or RF field . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1.3 Free Induction Decays and Spin Echos . . . . . . . . . . . . . . . . . 6 2.2 Gradient Fields: Encoding Spatial Information . . . . . . . . . . . . . . . . . 7 2.2.1 Frequency Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2.2 Phase Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 The K-space Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3.1 Frequency Encoded Signals . . . . . . . . . . . . . . . . . . . . . . . 8 2.3.2 Phase Encoding Gradients . . . . . . . . . . . . . . . . . . . . . . . . 10 2.4 Basic Imaging Pulse Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . 10
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