Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jan 2009
Cerebral blood flow estimation in vivo using local tissue reference functions.
To evaluate the use of bolus signals obtained from tissue as reference functions (or local reference functions [LRFs]) rather than arterial input functions (AIFs) when deriving cross-calibrated cerebral blood flow (CBF(CC)) estimates via deconvolution. ⋯ If CBF is quantified using a patient-specific cross-calibration factor, then LRF CBF estimates are at least as accurate as those from AIFs. Therefore, until AIF quantification is achievable in vivo, perfusion protocols tailored for LRFs would simplify the methodology and provide more reliable perfusion information.
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J Magn Reson Imaging · Jan 2009
Clinical evaluation of automated scan prescription of knee MR images.
To compare an automated scan planning method to manual scan positioning in routine knee magnetic resonance imaging (MRI) studies. ⋯ Automated sequence prescription for knee MRI is feasible in clinical practice, with similar quality as manual positioning.
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J Magn Reson Imaging · Jan 2009
Imaging age-related cognitive decline: A comparison of diffusion tensor and magnetization transfer MRI.
To determine which MR technique was the most sensitive to age-related white matter damage. We compared both diffusion tensor imaging (DTI) and magnetization transfer (MT) maps to determine which technique correlated most strongly with cognitive function in a middle-aged and elderly community population. ⋯ DTI appears the most sensitive imaging parameter to determine age-related white matter damage. The stronger relationship with FA suggests that axonal damage is important in age-related cognitive decline.
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J Magn Reson Imaging · Jan 2009
Increased SNR and reduced distortions by averaging multiple gradient echo signals in 3D FLASH imaging of the human brain at 3T.
To demonstrate how averaging of multiple gradient echoes can improve high-resolution FLASH (fast low angle shot) magnetic resonance imaging (MRI) of the human brain. ⋯ SNR is gained efficiently by acquiring additional echoes and increasing TR (and flip angle accordingly to maintain contrast) until the associated T(2) (*) loss in the averaged signal consumes the sqrt(TR) increase in the steady state. A bandwidth of 350 Hz/pixel or higher and echo trains shorter than T(2) (*) are recommended.
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J Magn Reson Imaging · Jan 2009
Novel technique used to detect swallowing in volume-selective turbo spin-echo (TSE) for carotid artery wall imaging.
To improve three-dimensional (3D) volume-selective turbo spin-echo (TSE) carotid wall imaging by the addition of a novel body surface swallowing detection device. ⋯ Image quality can be improved by the algorithm during acquisition. This can be achieved by a novel, anatomically positioned superficial device. This may help in prolonged 3D scans where a single movement can corrupt the entire acquisition.