Journal ArticleDOI
Temperature mapping with MR imaging of molecular diffusion: application to hyperthermia.
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TLDR
Molecular diffusion is more sensitive than T1 and can be determined with high accuracy with MR imaging and has the potential to also help monitor blood perfusion in clinical hyperthermia.Abstract:
Efficacy and safety considerations for hyperthermia (HT) cancer therapy require accurate temperature measurements throughout the heated volume. Noninvasive thermometry methods have been proposed, including magnetic resonance (MR) imaging based on the temperature dependence of the relaxation time T1. However, the temperature accuracy achieved to date with T1 measurements does not fulfill the HT requirements (1 degree C/cm). The authors propose to use molecular diffusion, for which temperature dependence is well known. Molecular diffusion is more sensitive than T1 and can be determined with high accuracy with MR imaging. Diffusion and derived temperature images were obtained with a 2 X 2-mm pixel size in a polyacrylamide gel phantom heated inside the head coil of a clinical 0.5-T whole-body MR imaging system by means of a modified clinical HT device made compatible with the system. Temperatures determined from these images with 0.8-cm2 regions of interest were found to be within 0.5 degrees C of those recor...read more
Citations
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Journal ArticleDOI
Diffusion-Weighted Magnetic Resonance Imaging as a Cancer Biomarker: Consensus and Recommendations
Anwar R. Padhani,Guoying Liu,Dow Mu-Koh,Thomas L. Chenevert,Harriet C. Thoeny,Taro Takahara,Andrew Dzik-Jurasz,Brian D. Ross,Marc Van Cauteren,David J. Collins,Dima A. Hammoud,Gordon J. S. Rustin,Bachir Taouli,Peter L. Choyke +13 more
TL;DR: DW-MRI should be tested as an imaging biomarker in the context of well-defined clinical trials, by adding DW-MRI to existing NCI-sponsored trials, particularly those with tissue sampling or survival indicators, and standards for measurement, analysis, and display are needed.
Journal ArticleDOI
Early detection of regional cerebral ischemia in cats: comparison of diffusion- and T2-weighted MRI and spectroscopy.
Michael E. Moseley,Yoram Cohen,J Mintorovitch,Laureano Chileuitt,Hiroaki Shimizu,John Kucharczyk,Michael F. Wendland,Philip Weinstein +7 more
TL;DR: Diffusion‐weighted hyperintensity in ischemic tissues may be temperature‐related, due to rapid accumulation of diffusion‐restricted water in the intracellular space (cytotoxic edema) resulting from the breakdown of the transmembrane pump and/or to microscopic brain pulsations.
Journal ArticleDOI
Diffusion-tensor MRI: theory, experimental design and data analysis - a technical review.
Peter J. Basser,Derek K. Jones +1 more
TL;DR: In this article, the theoretical underpinnings of diffusion-tensor magnetic resonance imaging (DT-MRI), as well as experimental design and data analysis issues are discussed. And new statistical methods have been developed to analyse DT-MRI data, and their potential uses in clinical and multi-site studies.
Journal ArticleDOI
Magnetic fluid hyperthermia: focus on superparamagnetic iron oxide nanoparticles.
TL;DR: In this review, the limitations and recent advances in the development of superparamagnetic iron oxide nanoparticles for hyperthermia are presented.
Journal ArticleDOI
A precise and fast temperature mapping using water proton chemical shift.
Yasutoshi Ishihara,Calderon A,Hidehiro Watanabe,Kazuya Okamoto,Yoshinori Suzuki,Kagayaki Kuroda +5 more
TL;DR: A new temperature measurement procedure using phase mapping was developed that makes use of the temperature dependence of the water proton chemical shift and highly accurate and fast measurements were obtained during phantom and in vivo experiments.
References
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Journal ArticleDOI
Spin diffusion measurements : spin echoes in the presence of a time-dependent field gradient
E. O. Stejskal,J. E. Tanner +1 more
TL;DR: In this article, a derivation of the effect of a time-dependent magnetic field gradient on the spin-echo experiment, particularly in the presence of spin diffusion, is given.
Journal ArticleDOI
Effects of Diffusion on Free Precession in Nuclear Magnetic Resonance Experiments
H. Y. Carr,Edward M. Purcell +1 more
TL;DR: In this paper, the effect of diffusion on free precession in nuclear resonance has been studied, and a new scheme for measuring the transverse relaxation time is described, which largely circumvents the diffusion effect.
Journal ArticleDOI
MR imaging of intravoxel incoherent motions: application to diffusion and perfusion in neurologic disorders.
TL;DR: A magnetic resonance (MR) method to image intravoxel incoherent motions (IVIMs) by using appropriate gradient pulses and nonuniform slow flow of cerebrospinal fluid appeared as a useful feature on IVIM images.
Journal ArticleDOI
Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging.
TL;DR: Clinical results showed significant promise of the IVIM method for tissue characterization by perfusion patterns and for functional studies in the evaluation of the microcirculation in physiologic and pathologic conditions, as, for instance, in brain ischemia.
Journal ArticleDOI
A review of normal tissue hydrogen NMR relaxation times and relaxation mechanisms from 1-100 MHz: dependence on tissue type, NMR frequency, temperature, species, excision, and age.
TL;DR: The longitudinal (T1) and transverse (T2) hydrogen (1H) nuclear magnetic resonance (NMR) relaxation times of normal human and animal tissue are compiled and reviewed as a function of tissue type, NMR frequency, temperature, species, in vivo versus in vitro status, time after excision, and age.