MRI Thermometry Based on Encapsulated Hyperpolarized Xenon

Schilling, Franz; Schröder, Leif; Palaniappan, Krishnan K.; Zapf, Sina; Wemmer, David E.; Pines, Alexander

doi:10.1002/cphc.201000507

Cited by 47 publications

(37 citation statements)

References 25 publications

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“…By virtue of having a large electron cloud, xenon’s chemical shift is very sensitive to changes in its physical and chemical environment. Schilling et al leveraged on this property to develop a 129 Xe-based temperature sensor (30). Specifically, the strong chemical shift difference between cryptophane-bound (31) xenon and unbound xenon (−0.29 ppm/°C) was used to measure absolute temperature in vitro in an aqueous suspension containing the sensor at a concentration of 150 μM with an accuracy of 0.1° C.…”

Section: Introductionmentioning

confidence: 99%

Accurate MR thermometry by hyperpolarized ¹²⁹Xe

Zhang

Burant

McCallister

et al. 2016

Magnetic Resonance in Med

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Purpose To investigate the temperature dependence of the resonance frequency of Lipid-Dissolved Xenon (LDX) and to assess the accuracy of LDX-based MR thermometry. Methods The chemical shift temperature dependence of water protons, methylene protons, and LDX was measured from samples containing tissues with varying fat contents using a high-resolution NMR spectrometer. LDX results were then used to acquire relative and absolute temperature maps in vivo and the results were compared to PRF-based MR thermometry. Results The temperature dependence of PRF is strongly affected by the specific distribution of water and fat. A redistribution of water and fat compartments can reduce the apparent temperature dependence of the water chemical shift from −0.01ppm/°C to −0.006ppm, whereas the LDX chemical shift shows a consistent temperature dependence of −0.21ppm/°C. The use of the methylene protons resonance frequency as internal reference improves the accuracy of LDX-based MR thermometry but degrades that of PRF-based MR thermometry as microscopic susceptibility gradients affected lipid and water spins differently. Conclusion The LDX resonance frequency, with its higher temperature dependence, provides more accurate and precise temperature measurements, both in vitro and in vivo. More importantly, the resonance frequency of nearby methylene protons can be used to extract absolute temperature information.

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Section: Introductionmentioning

confidence: 99%

Accurate MR thermometry by hyperpolarized ¹²⁹Xe

Zhang

Burant

McCallister

et al. 2016

Magnetic Resonance in Med

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“…A few nuclei other than those from protons, such as 13 C [91], 31 P, [92,93] or 58 Co [94], demonstrate feasibility for thermometry, but it is difficult to find a specific reason to use them, because they are much less abundant than 1 H. The other possibility is to use hyperpolarized 129Xe [95], whose temperature dependence of the chemical shift in a cryptophane-A cage was reported to be 0.29 ppm/ C.…”

Section: Non-proton Nucleimentioning

confidence: 99%

Noninvasive Temperature Monitoring

Kuroda

2016

Hyperthermic Oncology From Bench to Bedside

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Noninvasive thermometry of target tissue is one of the key issues for successful and safe thermal therapy. Although various techniques using X-ray, infrared, photoacoustics, radiometry, impedance, ultrasound, and magnetic resonance imaging (MRI) have been investigated, to date, infrared imaging for skin surface or MRI for cross-sectional temperature distribution is accepted as a tool for clinical use. Since cross-sectional temperature distribution deep inside a human body is important in thermal therapy in general, practically, MRI is the only practical modality applicable for the therapies. Among several intrinsic MR parameters including proton density, spin-lattice relaxation time, spin-spin relaxation time, diffusion coefficient and chemical shift, the chemical shift is known to be the most reliable for temperature imaging in aqueous tissues. Because this parameter can be measured only from the resonance frequency of water protons and hence independent from the other parameters, which are measured based on the intensity of the MR signals. Phase mapping or spectroscopic technique are applicable for measuring and/or imaging distribution of temperature change. For adipose tissue spin-lattice relaxation time of fat may be used.

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“…Moreover the chemical shift of caged xenon varies when the host system is in the presence of the targeted receptor or analyte. Cryptophane encapsulated Xe can also be used as temperature sensor due to the linear temperature dependence of its chemical shift and even as local pH sensors [236,237]. …”

Section: Supramolecular Compoundsmentioning

confidence: 99%