Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · May 2012
Phase contrast MRI quantification of pulsatile volumes of brain arteries, veins, and cerebrospinal fluids compartments: repeatability and physiological interactions.
To study measurement repeatability and physiological determinants on measurement stability for phase contrast MRI (PC-MRI) measurements of cyclic volume changes (ΔV) of brain arteries, veins, and cerebrospinal fluid (CSF) compartments. ⋯ Repeatability of ΔV calculated from tCBF, tJBF, and CSF waveforms allows useful interpretations. The subject's time in the MR system and imaging resolution should be considered when interpreting volume changes. Summed CSF and venous volume changes was associated with arterial volume changes.
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J Magn Reson Imaging · May 2012
Comparative StudyImproving quality of arterial spin labeling MR imaging at 3 Tesla with a 32-channel coil and parallel imaging.
To compare 12-channel and 32-channel phased-array coils and to determine the optimal parallel imaging (PI) technique and factor for brain perfusion imaging using Pulsed Arterial Spin labeling (PASL) at 3 Tesla (T). ⋯ For PASL at 3T, the 32-channel coil at 3T provided better quality than the 12-channel coil. With the 32-channel coil, mSENSE 2 seemed to offer the best compromise for decreasing artifacts without significantly reducing SNR, CNR.
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J Magn Reson Imaging · May 2012
Comparative StudyComparison of T1-weighted in- and out-of-phase single shot magnetization-prepared gradient-recalled-echo with three-dimensional gradient-recalled-echo at 3.0 Tesla: preliminary observations in abdominal studies.
To describe in-phase (IP)/out-of-phase (OP) imaging with single shot magnetization-prepared gradient-recalled-echo (MP-GRE) and to compare intra-individually IP/OP MP-GRE with IP/OP three-dimensional gradient-recalled-echo (3D-GRE) at 3.0 Tesla (T). ⋯ Higher image quality and improved lesion detectability were present with IP/OP MP-GRE technique. Inversion-recovery prepared techniques may represent an important evolution for precontrast T1-weighted image at 3.0T. The good image quality of MP-GRE sequences acquired in a free breathing manner should recommend its use in patients unable to suspend breathing.
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To develop a magnetic resonance imaging (MRI) sequence (fluid and white matter suppression, FLAWS) for generating two sets of images from a single acquisition: one with contrast similar to a T1-weighted magnetization-prepared rapid gradient-echo sequence (MPRAGE) for structural definition; the other with nulled white matter (WM) signal intensity, similar to the fast gray matter T1 inversion recovery (FGATIR) sequence, for improved delineation of subcortical brain structures. ⋯ FLAWS provides two coregistered 3D volumes, one with nulled WM signal intensity and another with nulled cerebrospinal fluid. The coregistered nature of the two datasets allows for generating images that might be helpful in segmentation algorithms and clinical diagnosis.
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J Magn Reson Imaging · May 2012
Water-silicone separated volumetric MR acquisition for rapid assessment of breast implants.
To develop a robust T(2) -weighted volumetric imaging technique with uniform water-silicone separation and simultaneous fat suppression for rapid assessment of breast implants in a single acquisition. ⋯ The single volumetric acquisition with uniform water and silicone separation enables images to be reformatted into any orientation. This allows comprehensive assessment of breast implant integrity in less than 10 min of total examination time.