Temperature Dependence of Relaxation Times in Proton Components of Fatty Acids

Kuroda, Kagayaki; Iwabuchi, T.; Obara, Makoto; Honda, Masahiko; Saito, Kensuke; Imai, Yutaka

doi:10.2463/mrms.10.177

Cited by 30 publications

(52 citation statements)

References 9 publications

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“…These coefficients are more than 80 times higher than that of water. This complex also had temperature dependence in its [31]P signal, and the coefficient was 2.18 ppm/ C in vitro. Because this complex also has pH sensitivity in its proton chemical shifts, we can determine both temperature and pH simultaneously using two different proton signals, such as H 6 , as mentioned above, and H 2 at around +80 ppm [87,88].…”

Section: The Lanthanide Complexmentioning

confidence: 96%

“…Therefore it is indispensable to calibrate T 1 with temperature in the target tissues. One of the most significant application of using T 1 of proton is to measure temperature of fat, more specifically of the methylene chain or terminal methyl of fat [31]. Proton spectra of fat or oil comprise about nine components.…”

Section: Spin-lattice Relaxation Time Tmentioning

confidence: 99%

“…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%

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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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Section: The Lanthanide Complexmentioning

confidence: 96%

Section: Spin-lattice Relaxation Time Tmentioning

confidence: 99%

Section: Non-proton Nucleimentioning

confidence: 99%

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Noninvasive Temperature Monitoring

Kuroda

2016

Hyperthermic Oncology From Bench to Bedside

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“…One such approach is to use the T 1 of a methylene chain or terminal methyl proton of fat. 46 Proton spectra of fat or oil comprise about nine components. The most intense peak is the 2.1 ppm signal from protons on methylene chains (-CH 2 -) n of all the fatty acids in glycerides.…”

Section: Spectroscopic Parametric Measurementmentioning

confidence: 99%

“…In particular, MRS provides a variety of functionalities in addition to thermometry, such as the ability to observe nonwater protons like those in paramagnetic lanthanide compounds, 40-43 the effects of CEST (chemical exchange saturation transfer) and CEST agents, 44,45 as well as the chemical shifts of other nuclei, and other parameters in the spectral domain. 46,47 In this article I elucidate how MRS can be used for monitoring temperature.…”

Section: Introductionmentioning

confidence: 99%

Temperature Monitoring Using Chemical Shift

Kuroda

2016

eMagRes

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Methodologies in MRS provide noninvasive thermometry with a number of temperature-dependent MR parameters. Among these, the most representative is the proton chemical shift of the hydroxyl group. The electronic shielding effect of protons in this group changes linearly with temperature owing to intermolecular hydrogen bonding. Internally referenced measurements of the chemical shift difference between water and the protons in methyl or ethyl groups, whose frequencies are temperature insensitive, can provide precise measures of temperature. The proton chemical shift differences between water and N-acetylaspartate, creatine, choline, and the methylene chain in fat, or the relative change of the water proton chemical shift, may be used to monitor temperature in biological tissues. However, factors such as bulk susceptibility, electrolytes, pH, and macromolecules also affect chemical shifts in tissues. Although the internal reference technique can reduce the susceptibility effect, the bond-breaking effect of electrolytes can alter the absolute value, as well as the temperature coefficient of the chemical shift. Thus, absolute temperature monitoring in vivo has not been achieved to date. Nevertheless, monitoring relative temperature differences is useful. Alternative methodologies for MRS temperature monitoring include the use of proton chemical shifts in lanthanide complexes, chemical exchange saturation transfer agents, nonproton nuclei, spectroscopic T 1 measurements, and quantum coherence.

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