450. Basic study of Variable Flip Angle SE Method
نویسندگان
چکیده
منابع مشابه
Uncertainty in T(1) mapping using the variable flip angle method with two flip angles.
Propagation of errors, in conjunction with the theoretical signal equation for spoiled gradient echo pulse sequences, is used to derive a theoretical expression for uncertainty in quantitative variable flip angle T(1) mapping using two flip angles. This expression is then minimized to derive a rigorous expression for optimal flip angles that elucidates a commonly used empirical result. The theo...
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Introduction: The knowledge of flip angle values is essential for accurate modeling in many quantitative MRI techniques. Recently, Actual Flip Angle Imaging (AFI) was proposed to account for multiple sources of flip angle variations such as transmit field inhomogeneity, B0 variations, slab profile, and excitation pulse effects [1]. AFI was successfully applied to yield system-independent T1 rel...
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PURPOSE To improve the calculation of T1 relaxation time from a set of variable flip-angle (FA) spoiled gradient recalled echo images. MATERIALS AND METHODS The proposed method: (a) uses a uniform weighting of all FAs, (b) takes into account global inaccuracies in the generation of the prescribed FAs by estimating the actual FAs, and (c) incorporates data-driven local B1 inhomogeneity correct...
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1 Introduction The spin echo is a fundamental principle (1) that can be used for magnetic resonance imaging. Spin echo techniques are characterized by at least two rf-pulses. The first rf-pulse acts as an excitation pulse that converts longitudinal magnetization into transverse magnetization, and a second rf-pulse after TE/2 is used as a refocusing pulse that (partially) inverts the accumulated...
متن کاملSNR Analysis of Variable Refocusing Flip Angle FSE
R. F. Busse Applied Science Lab West, GE Medical Systems, Menlo Park, CA, United States Introduction For fast spin echo sequences, power can be greatly reduced while suffering only modest reduction in signal by using low flip angle refocusing pulses, provided the flip angles of the first few pulses are modulated so as to maintain pseudo-steady-state (pss) conditions in the spin system (1). Rece...
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ژورنال
عنوان ژورنال: Japanese Journal of Radiological Technology
سال: 1992
ISSN: 0369-4305,1881-4883
DOI: 10.6009/jjrt.kj00003500846