Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Mar 2007
Randomized Controlled Trial Comparative StudyDose comparison of single- vs. double-dose in contrast-enhanced magnetic resonance angiography of the carotid arteries: Intraindividual cross-over blinded trial using Gd-DTPA.
To compare the intraindividual differences of single-dose (D(S)) and double-dose (D(D)) gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)-enhanced magnetic resonance angiography (MRA) in the carotid arterial territory, an open-label single-center trial with blinded evaluations by two independent radiologists was undertaken. ⋯ Our results demonstrate that while a double dosing of contrast agent does increase SNR, it does not lead to further improvement in visual and perceptual image quality. A single dosage of approximately 0.1 mmol/kg body weight (bw) Gd-DTPA may be the preferable dosage in the carotid arteries.
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J Magn Reson Imaging · Mar 2007
Comparative Study Controlled Clinical TrialDifferentiation of SCA2 from MSA-C using proton magnetic resonance spectroscopic imaging.
To assess and compare biochemical and volumetric features of the cerebellum in patients with spinocerebellar ataxia type 2 (SCA2) and patients with the cerebellar variant of multiple system atrophy (MSA-C). ⋯ MRSI revealed Lac pathology in SCA2 but not in MSA-C. Whether this indicates distinct pathogenetic mechanisms of cerebellar degeneration remains to be established.
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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
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
Correction of proton resonance frequency shift temperature maps for magnetic field disturbances using fat signal.
To improve the immunity of the proton resonance frequency shift (PRFS) method of MRI temperature mapping against magnetic field disturbances. Since PRFS is a phase-sensitive method, it misinterprets magnetic field disturbances as artifact temperature changes. If not corrected, the resulting temperature artifacts can completely obscure the true temperature estimation, especially if the temperature elevations are small. ⋯ Our approach can be used for the guidance of thermal therapies involving tissues containing fat or surrounded by fat.