Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Sep 2009
Effect of shot number on the calculated apparent diffusion coefficient in phantoms and in human liver in diffusion-weighted echo-planar imaging.
To show the signal intensity varies with shot number in diffusion-weighted (DW) echo-planar imaging (EPI) and affects apparent diffusion coefficient (ADC) calculation. ⋯ The signal intensity can vary with shot number in SE EPI. For TR > or = 3000 msec, steady-state is attained after one shot. Using data acquired prior to steady-state confounds the calculation of ADC values.
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J Magn Reson Imaging · Sep 2009
Impact of audio/visual systems on pediatric sedation in magnetic resonance imaging.
To evaluate the use of an audio/visual (A/V) system in pediatric patients as an alternative to sedation in magnetic resonance imaging (MRI) in terms of wait times, image quality, and patient experience. ⋯ The A/V system was a successful method to reduce patient motion and obtain a quality diagnostic MRI without the use of sedation in pediatric patients. It provided a safer option, a positive experience, and decreased wait times.
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J Magn Reson Imaging · Sep 2009
Half-Fourier-acquisition single-shot turbo spin-echo (HASTE) MRI of the lung at 3 Tesla using parallel imaging with 32-receiver channel technology.
To assess the feasibility of half-Fourier-acquisition single-shot turbo spin-echo (HASTE) of the lung at 3 Tesla (T) using parallel imaging with a prototype of a 32-channel torso array coil, and to determine the optimum acceleration factor for the delineation of intrapulmonary anatomy. ⋯ Using optimized multi-element coil geometry HASTE-MRI of the lung is feasible at 3T with acceleration factors up to 4. Compared with nonaccelerated acquisitions, shorter echo times and reduced image blurring are achieved. Expiratory scanning may be favorable to compensate for susceptibility associated signal loss at 3T.
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J Magn Reson Imaging · Sep 2009
Prediction of cell necrosis with sequential temperature mapping after radiofrequency ablation.
To assess the feasibility of magnetic resonance (MR) thermometry after thermoablative therapy and to quantitatively evaluate the ability of two sequence types to predict cell necrosis. ⋯ Sequential MR temperature mapping allows for the prediction of the coagulation zone with an acceptable sensitivity and positive predictive value using EPI and GRE sequences.
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J Magn Reson Imaging · Sep 2009
Comparative StudyPre- and postoperative MR brain imaging with automatic planning and scanning software in tumor patients: an intraindividual comparative study at 3 Tesla.
To evaluate the feasibility of automatic planning and scanning of brain MR imaging (MRI) protocols on a clinical 3 Tesla system in tumor patients before and after neurosurgical intervention. ⋯ Automatic planning and scanning before and after brain surgery yields robust results in most of the patients with substantial shape deviations. The dimensions of necessary geometry corrections are predominantly small. These results are promising to minimize interscan variability in longitudinal studies.