Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Dec 2007
Alteration of blood oxygenation level-dependent signaling by local circulatory condition.
To determine regional differences in the relationship between neuronal activation and blood oxygenation level-dependent (BOLD) signal changes. ⋯ Insufficient perfusion pressure in these regions may have led to attenuation of BOLD and perfusion responses to stimulation of a large portion of the visual field, or a condition in which a large extent of the visual areas was activated in the proximal regions of the territories perfused by the middle and posterior cerebral arteries. This finding supports the hypothesis that regional differences in circulatory condition can result in alterations of the relationship between neuronal activation and BOLD signal changes in the normal human brain.
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J Magn Reson Imaging · Dec 2007
MRI evaluation of microvascular obstruction in experimental reperfused acute myocardial infarction using a T1 and T2 preparation pulse sequence.
To investigate a T1 and T2 preparation pulse sequence to evaluate microvascular obstruction (MO) in a porcine model of reperfused acute myocardial infarction (AMI). ⋯ Using T1 preparation under a constant gadopentetate dimeglumine (Gd-DTPA) infusion, delayed imaging at 30 to 45 minutes demonstrates MO as a positive contrast with larger T1 values. Elevated T1 and T2 values in MO precontrast may also help to differentiate them from both control and DHE regions.
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J Magn Reson Imaging · Dec 2007
Black-blood imaging of the human heart using rapid stimulated echo acquisition mode (STEAM) MRI.
To develop a rapid stimulated echo acquisition mode (STEAM) MRI technique for "black-blood" imaging of the human heart that overcomes the single-slice limitation and partially compromised blood suppression associated with double inversion-recovery techniques. ⋯ Rapid STEAM MRI of the heart emerges as a simple technique for multislice imaging of the myocardial wall with efficient flow suppression.
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J Magn Reson Imaging · Dec 2007
Correlation of lung parenchymal MR signal intensity with pulmonary function tests and quantitative computed tomography (CT) evaluation: a pilot study.
To evaluate the effect of ventilatory impairment on MR signal intensity of the lung parenchyma. ⋯ In COPD patients, lung signal change measured by MRI correlates with airflow obstruction, but not with volume of the emphysema measured by lung CT.
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J Magn Reson Imaging · Dec 2007
Comparative StudyDirect comparison of myocardial perfusion cardiovascular magnetic resonance sequences with parallel acquisition.
To directly compare the three main myocardial perfusion cardiovascular magnetic resonance (CMR) sequences incorporating parallel acquisition methods. ⋯ The hEPI sequence scored best for diagnostic performance despite the SSFP sequence having greater CNR. This trial favors hEPI for clinical myocardial perfusion CMR and suggests CNR should not be the sole criterion used to gauge the best candidate sequence.