Journal of magnetic resonance imaging : JMRI
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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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To detect the earlier changes of the skeletal muscle of rats after peripheral nerve injury by measuring the apparent diffusion coefficient (ADC) on diffusion MR spectroscopy. ⋯ The ADC of the skeletal muscle increased quickly after the transection of the dominant peripheral nerve and was detectable one day after the surgery. Diffusion MRI can be a useful tool for early detection of peripheral nerve injury instead of T2-weighted MRI or electromyography (EMG).
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J Magn Reson Imaging · Nov 2007
Calculation of MRI-induced heating of an implanted medical lead wire with an electric field transfer function.
To develop and demonstrate a method to calculate the temperature rise that is induced by the radio frequency (RF) field in MRI at the electrode of an implanted medical lead. ⋯ The transfer function is proposed as an efficient method to calculate MRI-induced heating at an electrode of a medical lead. Measured temperature rises of a model implant in a phantom were in good agreement with the rises predicted by the transfer function. The transfer function could be numerically or experimentally determined.
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To describe what, if any, specific long T(2)-related abnormalities occur in the white matter of subjects with either phenylketonuria (PKU) or multiple sclerosis (MS). ⋯ This study supports the usefulness of increasing the data acquisition window of the multiecho T(2) relaxation sequence to better characterize the T(2) decay from pathological brain.