Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Feb 2014
Randomized Controlled Trial Multicenter StudyGadobutrol in the central nervous system at three doses: results from a phase II, randomized, multicenter trial.
To investigate the efficacy and safety of three doses of gadobutrol and determine the minimum effective dose for contrast-enhanced MRI of the central nervous system (CNS). ⋯ The 0.1 mmol/kg dose of gadobutrol was effective and well tolerated for contrast-enhanced MRI of the CNS.
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J Magn Reson Imaging · Feb 2014
ReviewWhole-body simultaneous positron emission tomography (PET)-MR: optimization and adaptation of MRI sequences.
The purpose of this article is to introduce the underlying challenges associated with the incorporation of magnetic resonance imaging (MRI) into the new hybrid imaging modality simultaneous positron emission tomography (PET)/MR and their impact on attenuation correction, sequence optimization, and protocol development. Many adjustments to MR sequences are necessary for optimal whole-body and fused image results.
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Integrated whole-body PET/MR hybrid imaging combines excellent soft tissue contrast and various functional imaging parameters provided by MR with high sensitivity and quantification of radiotracer metabolism provided by positron emission tomography (PET). While clinical evaluation now is under way, integrated PET/MR demands for new technologies and innovative solutions, currently subject to interdisciplinary research. Attenuation correction of human soft tissues and of hardware components has to be MR-based to maintain quantification of PET imaging because computed tomography (CT) attenuation information is missing. ⋯ The hybrid imaging workflow here has to be tailored to the clinical indication to maximize diagnostic information while minimizing acquisition time. PET/MR introduces new artifacts that need special observation and innovative solutions for correction. Finally, the rising need for appropriate phantoms and standardization efforts in PET/MR hybrid imaging is discussed.
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J Magn Reson Imaging · Feb 2014
Regional mapping of gas uptake by blood and tissue in the human lung using hyperpolarized xenon-129 MRI.
To develop a breathhold acquisition for regional mapping of ventilation and the fractions of hyperpolarized xenon-129 (Xe129) dissolved in tissue (lung parenchyma and plasma) and red blood cells (RBCs), and to perform an exploratory study to characterize data obtained in human subjects. ⋯ Regional maps of tissue and RBC fractions of dissolved Xe129 were obtained from a short breathhold acquisition, well tolerated by healthy volunteers and subjects with obstructive lung disease. Marked differences were observed in spatial distributions and overall amounts of Xe129 dissolved in tissue and RBCs among healthy subjects, smokers and asthmatics.
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J Magn Reson Imaging · Feb 2014
Comparative StudyEvaluation of hepatic focal lesions using diffusion-weighted MR imaging: comparison of apparent diffusion coefficient and intravoxel incoherent motion-derived parameters.
To determine whether parameters obtained from intravoxel incoherent motion (IVIM)-diffusion-weighted imaging (DWI) using multiple b-values can improve characterization of common focal liver lesions (FLLs), compared with the apparent diffusion coefficient (ADCtotal ). ⋯ Dt provided better diagnostic performance than ADCtotal in differentiating benign from malignant lesions. Dp and f were significant parameters for diagnosing hypervascular FLLs.