Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jan 2016
Triexponential function analysis of diffusion-weighted MRI for diagnosing prostate cancer.
To evaluate more detailed information noninvasively through on diffusion and perfusion in prostate cancer (PCa) using triexponential analysis of diffusion-weighted imaging (DWI). ⋯ Triexponential analysis is a noninvasive approach that can provide more detailed information regarding diffusion and perfusion of PCa than biexponential analysis.
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J Magn Reson Imaging · Jan 2016
Influence of temporal regularization and radial undersampling factor on compressed sensing reconstruction in dynamic contrast enhanced MRI of the breast.
To evaluate the influence of temporal sparsity regularization and radial undersampling on compressed sensing reconstruction of dynamic contrast-enhanced (DCE) MRI, using the iterative Golden-angle RAdial Sparse Parallel (iGRASP) MRI technique in the setting of breast cancer evaluation. ⋯ This study demonstrates objective spatial and temporal similarity measures can be used to assess the influence of sparsity constraint and undersampling in compressed sensing DCE-MRI and also shows that the iGRASP method provides the flexibility of optimizing these reconstruction parameters in the postprocessing stage using the same acquired data.
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J Magn Reson Imaging · Jan 2016
Comparative StudyMP2RAGE for deep gray matter measurement of the brain: A comparative study with MPRAGE.
To compare magnetization-prepared two rapid acquisition gradient echoes (MP2RAGE) imaging with conventional MPRAGE imaging for deep gray matter (GM) segmentation, reproducibility, contrast ratio (CR) and contrast-to-noise ratio (CNR), and to evaluate reproducibility of T1 maps derived from MP2RAGE. ⋯ MP2RAGE yields greater reproducibility and better tissue contrast than MPRAGE in deep GM. T1 maps derived from MP2RAGE were highly reliable. MP2RAGE is useful for measurement and analysis of deep GM.
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J Magn Reson Imaging · Jan 2016
Comparative StudyReliability of 7T (1) H-MRS measured human prefrontal cortex glutamate, glutamine, and glutathione signals using an adapted echo time optimized PRESS sequence: A between- and within-sessions investigation.
To ascertain the mechanisms of neuropsychiatric illnesses and their treatment, accurate and reliable imaging techniques are required; proton magnetic resonance spectroscopy ((1) H-MRS) can noninvasively measure glutamatergic function. Evidence suggests that aberrant glutamatergic signaling plays a role in numerous psychopathologies. Until recently, overlapping glutamatergic signals (glutamate, glutamine, and glutathione) could not easily be separated. However, the advent of novel pulse sequences and higher field magnetic resonance imaging (MRI) allows more precise resolution of overlapping glutamatergic signals, although the question of signal reliability remains undetermined. ⋯ The adapted sequence provides good reliability to measure glutamate, glutamine, and glutathione signals.
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J Magn Reson Imaging · Jan 2016
Retrospective head motion correction approaches for diffusion tensor imaging: Effects of preprocessing choices on biases and reproducibility of scalar diffusion metrics.
To evaluate how retrospective head motion correction strategies affect the estimation of scalar metrics commonly used in clinical diffusion tensor imaging (DTI) studies along with their across-session reproducibility errors. ⋯ The use of an iteratively averaged b0 image as motion correction reference (as performed by DTIPrep) affects both scalar values and improves test-retest reliability relative to the other tested pipelines. These considerations are potentially relevant for data analysis in longitudinal DTI studies.