Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jul 2014
T₁ mapping using variable flip angle SPGR data with flip angle correction.
To improve the calculation of T1 relaxation time from a set of variable flip-angle (FA) spoiled gradient recalled echo images. ⋯ The proposed method overcomes some inaccuracies in FA production, providing more accurate estimation of T1 values compared with standard methods, and is applicable for currently available data.
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Arterial spin labeling (ASL) methods allow for quantitative mapping of tissue perfusion in absolute units, without the use of contrast agents. In this technique, the magnetization of arterial blood water is labeled by magnetic inversion or saturation, and the delivery of labeled blood water to tissues is observed. In this review three classes of labeling methods for ASL are described and compared: continuous, pulsed, and velocity-selective. The quantification of perfusion from ASL data is discussed, and methods for the extraction of new types of information using ASL and related techniques, such as mapping of vascular territories or venous oxygenation, are described.