Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Apr 2006
Focal liver lesions: breathhold gradient- and spin-echo T2-weighted imaging for detection and characterization.
To evaluate breathhold gradient- and spin-echo (GRASE) T2-weighted imaging for the detection and characterization of focal liver lesions. ⋯ T2-weighted breathhold GRASE has the potential to provide faster liver imaging.
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J Magn Reson Imaging · Apr 2006
Calculation of cerebral perfusion parameters using regional arterial input functions identified by factor analysis.
To calculate regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional mean transit time (rMTT) accurately, an arterial input function (AIF) is required. In this study we identified a number of AIFs using factor analysis of dynamic studies (FADS), and performed the cerebral perfusion calculation pixel by pixel using the AIF that was located geometrically closest to a certain voxel. ⋯ This study indicates that the use of FADS and the nearest-AIF method is preferable to manual selection of one single AIF.
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To develop a novel pulse sequence called spin-locked echo planar imaging (EPI), or (SLEPI), to perform rapid T1rho-weighted MRI. ⋯ We demonstrate the feasibility of the SLEPI pulse sequence to perform rapid T1rho MRI. The sequence produced images of higher quality than a gradient-echo EPI sequence for the same contrast evolution times. We also discuss applications and limitations of the pulse sequence.