The Spin-Echo System Reconsidered
نویسندگان
چکیده
منابع مشابه
Fast Spin Echo Imaging
In conventional spin echo (SE) imaging, the longitudinal magnetization (that is generated by the presence of the main magnetic field, B0) is tipped into the transverse plane using a radiofrequency (RF) pulse that tips the magnetization 90 degrees. Once in the transverse plane, the magnetization rotates, or precesses, around the axis of the main magnetic field. As the transverse magnetization pr...
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A new approach to spin-echo imaging is presented in which the 180 degrees RF pulse refocuses two or more spin-echoes at different positions in the readout period. When simultaneous echo refocusing (SER) is implemented using multiple 180 degrees pulses, an undesirable mixing of stimulated echoes and primary echoes from different slices can occur. A novel periodic gradient spoiler scheme eliminat...
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Imaging with T2-weighting is prescribed in nearly every diagnostic imaging protocol, owing to the fact that in many pathologic states, diseased tissue may be distinguished from normal tissue through apparent differences in T2. Conventional T2-weighted imaging carries with it a heavy time cost, however, as a relatively long time must be allowed between acquisitions in order to allow T1 recovery ...
متن کاملAssessment of the Characteristics of MRI Coils in Terms of RF Non-Homogeneity Using Routine Spin Echo Sequences
Introduction: One of the major causes of image non-uniformity in MRI is due to the existence of non-homogeneity in RF receive and transmit. This can be the most effective source of error in quantitative studies in MRI imaging. Part of this non-homogeneity demonstrates the characteristics of RF coil and part of it is due to the interaction of RF field with the material being imaged...
متن کاملcomparison of maximum signal intensity of magnevist contrast agent in modified t1 weighted spin echo, t1 weighted fast spin echo and t1 weighted gradient echo sequences
background: nowadays mri examinations have been widely used in clinical applications for many diagnoses. the use of contrast agent in mri improves lesion detection and characterization and causes more accurate diagnosis. objectives: the aim of this study was comparing to optimal dose of magnevist contrast agent in modified t1w se (spin echo), t1w fse (fast spin echo) and t1w gre (gradient ech...
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ژورنال
عنوان ژورنال: Foundations of Physics
سال: 2004
ISSN: 0015-9018
DOI: 10.1023/b:foop.0000019630.61758.b6