Journal of magnetic resonance imaging : JMRI
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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
Multicompartmental analysis of late contrast enhancement in areas of myocardial infarction supplied by chronically occluded coronary arteries.
To analyze the relationship between late contrast enhancement (LCE) and the interstitial distribution volume (V(In)) of gadolinium (Gd) tracers in the myocardial infarction (MI) areas supplied by chronically occluded arteries from patients. In animal experimental models, LCE has already been shown to correspond to an enhanced V(In) of Gd tracers and thus, to a decrease in the amount of intact cells. ⋯ Detection of LCE in the MI territories supplied by chronically occluded arteries relates to the difference in the V(In) of tracers between the infarct and the noninfarct areas.
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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
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
Combination of Mn(2+)-enhanced and diffusion tensor MR imaging gives complementary information about injury and regeneration in the adult rat optic nerve.
To evaluate manganese (Mn(2+))-enhanced MRI (MEMRI) and diffusion tensor imaging (DTI) as tools for detection of axonal injury and regeneration after intravitreal peripheral nerve graft (PNG) implantation in the rat optic nerve (ON). ⋯ MEMRI and DTI enabled detection of functional and structural degradation after rat ON injury, and there was correlation between the MRI-derived and immunohistochemical measures of axon regeneration.