Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Apr 2009
Comparative StudyQuantitative and qualitative comparison of 1.5 and 3.0 Tesla MRI in patients with chronic liver diseases.
To compare the quantitative and qualitative image quality intra-individually, at 1.5 and 3.0 Tesla (T) in patients with chronic liver diseases. ⋯ The SNRs of various abdominal tissues demonstrated significant increases at 3.0 T. The image quality of 3D-GE sequences was higher at 3.0 T, whereas the image quality of precontrast SGE sequences was higher at 1.5T.
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J Magn Reson Imaging · Apr 2009
Diffusion tensor and tensor metrics imaging in intracranial epidermoid cysts.
To explore the utility of diffusion tensor imaging (DTI) and diffusion tensor metrics (DTM) in characterizing the structural pathology of epidermoid cysts. DTI gives information about the tissue structure; a high fractional anisotropy (FA) indicates a highly structured orientation of the tissue, fibers, or white matter tracts. Based on the tensor rank, a set of three metrics has been described that can be used to measure the directional dependence of diffusion: linear anisotropy (CL), planar anisotropy (CP), and spherical anisotropy (CS). DTM takes into account the shape of diffusion anisotropy and hence may provide better insight into the orientation of structures than FA. ⋯ High CP values suggest preferential diffusion of water molecules along a two-dimensional geometry, which could be attributed to the well-structured orientation of keratin filaments and flakes within the tumor as demonstrated by histopathology. Advanced imaging modalities like DTI with DTM can provide information regarding the microstructural anatomy of the epidermoid cysts.
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J Magn Reson Imaging · Apr 2009
Randomized Controlled Trial Multicenter Study Comparative StudyMulticenter, double-blind, randomized, intra-individual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine in MRI of brain tumors at 3 tesla.
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J Magn Reson Imaging · Apr 2009
Comparative StudyAccelerated phase-contrast MR imaging: comparison of k-t BLAST with SENSE and Doppler ultrasound for velocity and flow measurements in the aorta.
To evaluate differences in velocity and flow measurements in the aorta between accelerated phase-contrast (PC) magnetic resonance imaging (MRI) using SENSE and k-t BLAST and in peak velocity to Doppler ultrasound. ⋯ Peak velocity of accelerated PC-MRI correlated with CW Doppler measurements, but high k-t BLAST acceleration factors lead to a significant underestimation. SENSE with R = 2 and 2-fold k-t BLAST are most highly correlated in phase-contrast flow measurements.
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J Magn Reson Imaging · Apr 2009
fMRI activation mapping as a percentage of local excitation: consistent presurgical motor maps without threshold adjustment.
To evaluate the performance of a relative activation amplitude algorithm, versus standard t-value thresholding, for reliably establishing the location, amplitude, and spatial extent of functional magnetic resonance imaging (fMRI) brain activation for presurgical planning. ⋯ The reproducibility and anatomical specificity of the spatiotemporal pattern of BOLD activation makes relative amplitude fMRI mapping a useful tool for clinical imaging, where accuracy, reproducibility, and quality control are critical concerns.