A phase-sensitive method of flip angle mapping
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 analyze the flip-angle dependence and to optimize the statistical precision of a fast three-dimensional T1-mapping technique based on the variable-flip-angle (VFA) method. The proposed single-flip-angle (1FA) approach acquires only a single 3D spoiled gradient-echo data set for each time point of the dynamical series in combination with a longer baseline measurement. Theory and Meth...
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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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Introduction For successful RF coil development and improvement, coil characterization plays an essential role. A quantitative map of the magnetic field produced per unit current (B1unit+) provides information about the coil efficiency as well as its sensitivity distribution [1]. This allows one to predict SNR, homogeneity and sensitive volume. A mapping method with high accuracy over a large d...
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ژورنال
عنوان ژورنال: Magnetic Resonance in Medicine
سال: 2008
ISSN: 0740-3194,1522-2594
DOI: 10.1002/mrm.21729