Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Mar 2007
Precision, signal-to-noise ratio, and dose optimization of magnitude and phase arterial input functions in dynamic susceptibility contrast MRI.
To determine optimal conditions for precise measurement of arterial input function (AIFs) in dynamic susceptibility contrast (DSC) perfusion MRI. ⋯ AIF SNR is affected most by signal type, then dosing, and lastly, SNR(I(0)).
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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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To combine gradient-echo (GRE) imaging with a multipoint water-fat separation method known as "iterative decomposition of water and fat with echo asymmetry and least squares estimation" (IDEAL) for uniform water-fat separation. Robust fat suppression is necessary for many GRE imaging applications; unfortunately, uniform fat suppression is challenging in the presence of B(0) inhomogeneities. These challenges are addressed with the IDEAL technique. ⋯ IDEAL-SPGR provides robust water-fat separation with optimized SNR performance at both 1.5T and 3.0T with multicoil acquisitions and parallel imaging in multiple regions of the body.
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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
Malignant-lesion segmentation using 4D co-occurrence texture analysis applied to dynamic contrast-enhanced magnetic resonance breast image data.
To investigate the use of four-dimensional (4D) co-occurrence-based texture analysis to distinguish between nonmalignant and malignant tissues in dynamic contrast-enhanced (DCE) MR images. ⋯ This study shows that a neural network classifier based on 4D texture analysis inputs can achieve a performance comparable to that achieved by human observers, and that further research in this area is warranted.