Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jun 2007
Clinical aspects of the apparent diffusion coefficient in 3He MRI: results in healthy volunteers and patients after lung transplantation.
To measure the apparent diffusion coefficient (ADC) after inhalation of hyperpolarized (3)He in healthy volunteers and lung transplant recipients, and demonstrate the gravity dependence of ADC values. ⋯ An anterior-posterior (A/P) gradient was found in inspiration and expiration in healthy lungs. Healthy, transplanted, and native diseased lungs had significantly different mean ADC values. From our preliminary results, (3)He MRI appears to be sensitive for detecting areas of abnormal ventilation in transplanted lungs.
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J Magn Reson Imaging · Jun 2007
High-speed 3T MR spectroscopic imaging of prostate with flyback echo-planar encoding.
Prostate MR spectroscopic imaging (MRSI) at 3T may provide two-fold higher spatial resolution over 1.5T, but this can result in longer acquisition times to cover the entire gland using conventional phase-encoding. In this study, flyback echo-planar readout trajectories were incorporated into a Malcolm Levitt's composite-pulse decoupling sequence (MLEV)-point-resolved spectroscopy sequence (PRESS) to accelerate the acquisition of large array (16 x 16 x 8), high spatial (0.154 cm(3)) resolution MRSI data by eight-fold to just 8.5 minutes. ⋯ Easy data reconstruction and the robustness of the flyback echo-planar encoding make this technique particularly suitable for the clinical setting. The short acquisition time provided by this method reduces the 3T prostate MRI/MRSI exam time, allows longer repetition times, and/or allows the acquisition of additional MR acquisitions within the same exam.
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J Magn Reson Imaging · Jun 2007
Black-blood T2* technique for myocardial iron measurement in thalassemia.
To compare the effectiveness and reproducibility of a new black-blood sequence vs. a conventional bright-blood gradient-echo T2* sequence for myocardial iron overload measurement in thalassemia. ⋯ The black-blood T2* technique yields high-contrast myocardial images, provides clearly depicted myocardial borders, and avoids blood signal contamination of the myocardium while yielding improvements in interobserver variability.
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J Magn Reson Imaging · Jun 2007
High temporal resolution breathheld 3D FIESTA CINE imaging: validation of ventricular function in patients with chronic myocardial infarction.
To develop a gated single-breathhold, high temporal resolution three-dimensional (3D) CINE imaging technique and to evaluate its accuracy in volumetric and functional quantification in patients with chronic myocardial infarction. ⋯ High temporal resolution 3D CINE SSFP imaging of the whole heart can be obtained in a single breathhold and yield ventricular function measurements similar to 2D CINE methods.
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J Magn Reson Imaging · Jun 2007
Quantification of perfusion and permeability in breast tumors with a deconvolution-based analysis of second-bolus T1-DCE data.
To test the feasibility of using a second-bolus injection, added to a routine breast MRI examination, to measure regional perfusion and permeability in human breast tumors. ⋯ In terms of these perfusion values, our method appears promising to quantitatively characterize tumor pathophysiology. However, the number of patients was limited, and the separation between malignant and benign groups was not clear-cut. Additional parameters generated through compartment modeling may improve the tumor differentiation.