Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Sep 2006
Comparing MR image intensity standardization against tissue characterizability of magnetization transfer ratio imaging.
To evaluate existing methods of standardization by exploiting the well-known tissue characterizing property of magnetization transfer ratio (MTR) values obtained from MT imaging, and compare the tissue characterizability of standardized T2, proton density (PD), and T1 images against the MTR images. ⋯ These results suggest that standardized T2, PD, and T1 images and their tissue-specific intensity signatures may be useful for characterizing disease.
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J Magn Reson Imaging · Sep 2006
Development of a novel optimized breathhold technique for myocardial T2 measurement in thalassemia.
To develop a reproducible fast spin-echo (FSE) technique for accurate myocardial T2 measurement with application to iron overload assessment in thalassemia. ⋯ The dynamic black-blood T2 sequence is a fast reproducible acquisition that compares favorably with conventional techniques, is robust to motion artifacts, and yields high blood-myocardium contrast. This technique may provide a useful tool in thalassemia and other scenarios requiring myocardial T2 quantification.
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J Magn Reson Imaging · Sep 2006
Feasibility of dynamic susceptibility contrast perfusion MR imaging at 3T using a standard quadrature head coil and eight-channel phased-array coil with and without SENSE reconstruction.
To investigate changes in image and dynamic signal-to-noise ratios (SNRs) of the DeltaR2* curve, as well as magnetic susceptibility-induced artifacts between a standard quadrature head coil and an eight-channel phased-array coil with and without sensitivity-encoding (SENSE) at 3T, compared to the current clinical standard head coil acquisition at 1.5T. ⋯ SENSE EPI at 3T yielded a significant improvement in dynamic SNR over the 1.5T acquisitions. A significant reduction in magnetic susceptibility-induced artifacts was achieved with SENSE EPI compared to the standard EPI eight-channel coil acquisition at 3T.
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J Magn Reson Imaging · Sep 2006
EPI image reconstruction with correction of distortion and signal losses.
To derive and implement a method for correcting geometric distortions and recovering magnetic resonance imaging (MRI) signal losses caused by susceptibility-induced magnetic field gradients (SFGs) in regions with large static field inhomogeneities in echo-planar imaging (EPI). ⋯ Results suggest that applying our method for reconstructing EPI images to reduce distortions and MRI signal losses is feasible.
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J Magn Reson Imaging · Sep 2006
In vivo R1-enhancement mapping of canine myocardium using ceMRI with Gd(ABE-DTTA) in an acute ischemia-reperfusion model.
To demonstrate the usefulness of normalized DeltaR1 (DeltaR1(n)) mapping in myocardial tissue following the administration of the contrast agent (CA) Gd(ABE-DTTA). ⋯ These results suggest that the extent of the severity of ischemia can be quantitatively represented by DeltaR1(n) maps obtained in the presence of our CA.