Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Apr 2006
Effect of contrast enhancement on the measurement of carotid arterial lumen and wall volume using MRI.
To investigate whether gadolinium (Gd)-based contrast enhancement (CE) affects high-resolution magnetic resonance imaging (MRI) measurements of carotid arterial wall volume. ⋯ Gd CE causes a significant increase in the apparent volume of the carotid wall throughout multiple carotid artery locations, which may be associated with improved visibility or neovascularization.
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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.