Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Mar 2007
Comparative Study Clinical TrialT2-weighted MRI of rectosigmoid carcinoma: comparison of respiratory-triggered fast spin-echo, breathhold fast-recovery fast spin-echo, and breathhold single-shot fast spin-echo sequences.
To compare the abilities of T2-weighted (T2W) imaging using respiratory-triggered fast spin-echo (RT-FSE), breathhold fast-recovery FSE (BH-FRFSE), and BH single-shot FSE (BH-SSFSE) sequences without an endorectal coil to detect rectosigmoid carcinomas. ⋯ The BH-FRFSE sequence may be the first choice for rectosigmoid T2W imaging in the prone position with per-anal air injection for patients who can hold their breath stably.
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J Magn Reson Imaging · Mar 2007
Projection-based estimation and nonuniformity correction of sensitivity profiles in phased-array surface coils.
To develop a novel approach for calculating the accurate sensitivity profiles of phased-array coils, resulting in correction of nonuniform intensity in parallel MRI. ⋯ The proposed method is more effective at correcting the intensity nonuniformity of phased-array surface-coil images than the conventional SOS method. In addition, the method was shown to be resilient to noise and was successfully applied for image reconstruction in parallel imaging.
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J Magn Reson Imaging · Mar 2007
Effects of RF inhomogeneity at 3.0T on ramped RF excitation: application to 3D time-of-flight MR angiography of the intracranial arteries.
To demonstrate the effects of inherent RF inhomogeneity on ramped RF excitation at 3.0T, and to introduce a simple correction for improving visualization of distal intracranial arteries in three-dimensional time-of-flight MR angiography (3D-TOF-MRA). ⋯ Ramped RF excitation is severely affected by RF interference at 3.0T, which makes the ramp profile suboptimal for distal intracranial blood vessels. A simple correction of the ramp slope can make a marked improvement.
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J Magn Reson Imaging · Mar 2007
Comparative StudyMRI of the female pelvis at 3T compared to 1.5T: evaluation on high-resolution T2-weighted and HASTE images.
To evaluate the feasibility of MRI of the female pelvis using high-resolution T2-weighted imaging (T2WI) and the half-Fourier acquisition single-shot turbo spin-echo (HASTE) technique at 3 Tesla (T) compared to 1.5T, while focusing on the uterine body and cervical anatomy. ⋯ Our results suggest that MRI of the female pelvis at 3T may potentially provide excellent images of the uterine cervix on high-resolution T2WI. New techniques to reduce inhomogeneity are thus called for.
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J Magn Reson Imaging · Mar 2007
Clinical TrialContrast-enhanced FLAIR imaging in combination with pre- and postcontrast magnetization transfer T1-weighted imaging: usefulness in the evaluation of brain metastases.
To assess whether the use of postcontrast fluid-attenuated inversion recovery (FLAIR) imaging in combination with pre- and postcontrast magnetization transfer (MT) T1-weighted imaging (T1WI) can increase diagnostic confidence in the evaluation of brain metastases. ⋯ The addition of postcontrast FLAIR imaging to pre- and postcontrast MT-T1WI improves diagnostic confidence in evaluation of brain metastases.