Journal of magnetic resonance imaging : JMRI
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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
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
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.