Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Dec 2002
The potential of contrast-enhanced magnetic resonance imaging for predicting left ventricular remodeling.
To determine whether the myocardial injury size on day 2 measured after gadolinium (Gd)-mesoporphyrin and Gd-diethylenetriamine-pentaacetic acid (DTPA) administration can be used for predicting left ventricular (LV) remodeling 8 weeks later, and to monitor the structural and functional changes in the infarct, peri-infarct rim, and remote myocardium in reperfused infarction using contrast-enhanced and functional magnetic resonance imaging (MRI) MATERIALS AND METHODS: Myocardial infarction (MI) was induced in 27 rats by 1 hour of coronary occlusion/reperfusion. Rats were imaged 2 days and 8 weeks after MI using MRI to determine LV function and size of myocardial injury. All animals received 0.05 mmol/kg Gd-mesoporphyrin 12 hours before the first MRI. A subgroup of 13 rats received 0.3 mmol/kg Gd-DTPA in addition to Gd-mesoporphyrin, and seven rats received 0.05 mmol/kg Gd-mesoporphyrin 12 hours before the second MRI for detection of healed MI. True infarct size (IS) and LV mass were measured postmortem. LV volumes, mass, function, and wall thickness were determined in both imaging sessions. ⋯ Contrast-enhanced MRI can be used as a noninvasive method for determining the initial size of myocardial injury and predicting later LV remodeling. MRI demonstrates the structural and functional changes in infarct, peri-infarct rim, and remote non-infarcted myocardium. The complementary use of functional and contrast-enhanced MRI may provide reliable assessment of therapeutic interventions to reduce IS and LV remodeling.
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J Magn Reson Imaging · Dec 2002
Dynamic contrast-enhanced myocardial perfusion imaging using saturation-prepared TrueFISP.
To develop and test a saturation-recovery TrueFISP (SR-TrueFISP) pulse sequence for first-pass myocardial perfusion imaging. ⋯ SR-TrueFISP first-pass MRI of myocardial perfusion leads to a substantial improvement of image quality and spatial resolution. It is well suited for first-pass myocardial perfusion studies at cardiovascular MR systems with improved gradient hardware.
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J Magn Reson Imaging · Dec 2002
Fat-suppressed three-dimensional MR angiography technique with elliptical centric view order and no prolonged breath-holding time.
To determine the appropriate rate of fat-suppression pulses (using spec IR-spectral selective inversion recovery) for fat-suppressed 3D magnetic resonance angiography (MRA) with an elliptical centric view order. ⋯ Two spec IR can be used for generation of partially fat-suppressed abdominal 3D MRA without prolongation of the breath-hold when performing 3D fast SPGR using an elliptical centric view order.
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J Magn Reson Imaging · Nov 2002
Single-voxel long TE 1H-MR spectroscopy of the normal brainstem and cerebellum.
To evaluate the feasibility of single voxel 1H-MRS of the CNS structures contained in the posterior cranial fossa and to determine the distribution of the normal metabolite ratios, concentrations, and T2 relaxation times in the midbrain, pons, medulla, dentate nucleus and cerebellar vermis. ⋯ With the exception of the medulla, single voxel 1H-MRS enables an in vivo biochemical analysis of the CNS structures contained in the posterior cranial fossa. Regional differences in the metabolite ratios and concentrations must be considered when employing 1H-MRS for evaluation of diseases of the brainstem and cerebellum.
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J Magn Reson Imaging · Nov 2002
Tissue thermal conductivity by magnetic resonance thermometry and focused ultrasound heating.
To investigate the combined use of magnetic resonance (MR) temperature imaging and focused ultrasound (FUS) for the noninvasive determination of tissue thermal properties. ⋯ This study has developed a method for determining tissue thermal properties specific to the patient and organ at the site of interest, and allows repeated application. This capability is relevant in thermal therapy planning of tumor ablation using MR-guided FUS systems.