Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jun 2008
Comparative StudyEstimation of absolute myocardial blood flow during first-pass MR perfusion imaging using a dual-bolus injection technique: comparison to single-bolus injection method.
To compare the dual-bolus to single-bolus quantitative first-pass magnetic resonance myocardial perfusion imaging for estimation of absolute myocardial blood flow (MBF). ⋯ Both single-bolus and dual-bolus perfusion methods correlate closely with MBF but the signal and contrast of the dual-bolus images are greater. With smaller nontransmural ROIs where signal is reduced, the dual-bolus method appeared to provide slightly more accurate results.
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J Magn Reson Imaging · Jun 2008
Clinical TrialHigh signal intensity halo around the carotid artery on maximum intensity projection images of time-of-flight MR angiography: a new sign for intraplaque hemorrhage.
To evaluate the value of the high signal intensity halo sign as a new marker of a fresh or recent intraplaque hemorrhage on the maximum intensity projection (MIP) images of time-of-flight (TOF) MR angiography. ⋯ High signal intensity halo around the carotid artery on the MIP images of TOF MR angiography is useful in the noninvasive detection of a fresh or recent carotid intraplaque hemorrhage.
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J Magn Reson Imaging · Jun 2008
Temporal evolution of MR perfusion in neonatal hypoxic-ischemic encephalopathy.
To illustrate the evolution of brain perfusion-weighted magnetic resonance imaging (PWI-MRI) in severe neonatal hypoxic-ischemic (HI) encephalopathy, and its possible relation to further neurodevelopmental outcome. ⋯ PWI in HI encephalopathy did not have the same temporal evolution as DWI, and remained abnormal for more than one week after injury. This could be a marker of an ongoing mechanism underlying severe neonatal HI encephalopathy. Evolution of PWI might help to predict further neurodevelopmental outcome.
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J Magn Reson Imaging · Jun 2008
Improvement of vessel visibility in time-of-flight MR angiography of the brain.
To improve vessel visibility in time-of-flight MR angiography (TOF-MRA) by careful consideration of coil choice, coil position, and frequency offset and profile of the nonspatially selective chemical shift selective (CHESS) presaturation pulse. ⋯ The excitation and the nonspatially selective CHESS pulses degraded the flow signal. Our results suggest that reduced spatial extent of RF pulse application to upstream flow can improve image quality of TOF-MRA. This result can be implemented on conventional scanners.
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J Magn Reson Imaging · Jun 2008
Improvement in B1-inhomogeneity artifacts in the abdomen at 3T MR imaging using a radiofrequency cushion.
To determine the impact of a radiofrequency (RF) cushion on abdominal image quality at 3T. ⋯ The RF cushion significantly improves image quality for abdominal imaging at 3T by reducing or eliminating B1-inhomogenity artifacts. This improved image quality is seen on turbo spin echo-based T2-weighted imaging such as HASTE but does not apply to gradient echo-based T2-weighted imaging such as the true-FISP sequence.