Spin-lattice relaxation times of bound water—Its determination and implications for tissue discrimination

Kaneoke, Yoshiki; Furuse, Masahiro; Inao, Suguru; Saso, K; Yoshida, Kazuo; Motegi, Yoko; Mizuno, Motomu; Izawa, Akira

doi:10.1016/0730-725x(87)90375-4

Cited by 28 publications

(33 citation statements)

References 19 publications

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“…Bound water content in gelatin gels calculated from reflection data is shown in Figure 3B. These data were in good agreement with the corresponding differential scanning calorimetry results for the bound water content of gelatin gels frequently cited in literature [Kaneoke et al, 1987].…”

Section: Water and Gel Measurementssupporting

confidence: 82%

Human skin permittivity determined by millimeter wave reflection measurements

Алексеев

Ziskin

2007

Bioelectromagnetics

169

156

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Millimeter wave reflection from the human skin was studied in the frequency range of 37-74 GHz in steps of 1 GHz. The forearm and palm data were used to model the skin with thin and thick stratum corneum (SC), respectively. To fit the reflection data, a homogeneous unilayer and three multilayer skin models were tested. Skin permittivity in the mm-wave frequency range resulted from the permittivity of cutaneous free water which was described by the Debye equation. The permittivity increment found from fitting to the experimental data was used for determination of the complex permittivity and water content of skin layers. Our approach, first tested in pure water and gelatin gels with different water contents, gave good agreement with literature data. The homogeneous skin model fitted the forearm data well. Permittivity of the forearm skin obtained with this model was close to the skin permittivity reported by others. To fit reflection from the palmar skin with a thick SC, a skin model containing at least two layers was required. Multilayer models provided better fitting to both the forearm and palmar skin reflection data. The fitting parameters obtained with different models were consistent with each other.

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Section: Water and Gel Measurementssupporting

confidence: 82%

Human skin permittivity determined by millimeter wave reflection measurements

Алексеев

Ziskin

2007

Bioelectromagnetics

169

156

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“…The corresponding k for cat white matter was measured to be 0.42 k 0.02. This value should be compared with 0.37 k 0.07 deduced from the data of Kaneoke et al ( 8 ) for human white matter. In Fig.…”

Section: Resultsmentioning

confidence: 96%

“…Linear regression analysis of the data yields the slopes and intercepts listed in Table 1. This particular form of plotting is dictated by the FETS model which predicts linearity between the relaxation rate and the inverse of the total water content ( 4 , 6,8 ) .…”

Section: Resultsmentioning

confidence: 99%

“…This bound water fraction includes both rotationally bound water molecules in the sense of Grosch and Noack ( 1 5 ) and a more loosely defined hydration layer extending several monolayers from the macromolecule surface. The above equation can be rewritten in the following form (8,18), which clearly indicates the dependence of T , on total water content Wand hydration fraction: These studies illustrate very convincingly the dominant role that total water content plays in determining the measured relaxation rates, as well as the basic validity of the two-state model in describing these particular systems. From the measured slopes B (Table 1 ), measured hydration fraction k (0.9), and Tlf of bulk water at 22°C (2.83 s), T; ; for gelatin can be determined by means of Eq.…”

Section: Ref (14)mentioning

confidence: 96%

“…However, full and accurate utilization of this approach requires a detailed understanding of the state of the accumulated water and the basic mechanisms underlying T , and T2 relaxation (4-8). In particular, local changes in T1 and T2 due to total water content and bound water fraction changes need to be carefully studied and quantified as they might reflect pathophysiological alterations (8). Also, with the dissemination of NMR imagers operating at different field strengths, it is important to obtain quantitative information on the frequency dependence of the relaxation rates so that meaningful comparisons of data reported from different laboratories can be attempted.…”

Section: Introductionmentioning

confidence: 99%

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In Vivo Brain Water Determination by T₁ Measurements: Effect of Total Water Content, Hydration Fraction, and Field Strength

Fatouros

Marmarou

Kraft

et al. 1991

Magnetic Resonance in Med

134

111

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This work is concerned with the accurate quantification of brain water content under routine clinical conditions. Gelatin solutions of varying water content are first employed as a model of an edematous brain and longitudinal relaxation measurements are performed at proton Larmor frequencies of 5, 41, 63, and 100 MHz. These are followed with in vivo measurements in an experimental animal model of brain edema at 41 MHz. The results underscore the dominant role of total water content W in the relaxation process and verify the expected linearity between 1/T1 and 1/W. A scheme is presented and experimentally verified at 41 MHz for deducing the exact relationship of 1/T1 vs 1/W at any frequency. Knowledge of this relationship along with precise measurements of 1/T1 at a given field strength permits quantitative in vivo measures of brain water content to be obtained with a precision of about 0.01. It is concluded that routine, accurate, and noninvasive brain water measurements are possible by magnetic resonance imaging in a clinical environment.

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T1 and magnetization transfer at 7 Tesla in acute ischemic infarct in the rat

et al. 1999

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T1 and magnetization transfer at a field strength of 7 Tesla were used to discriminate between water accumulation and protein mobilization in tissue undergoing infarction. Twelve rats subjected to acute stroke via intralumenal suture occlusion of the middle cerebral artery, and 19 controls, were studied. In MRI studies to 6 hr post‐ictus, serial data acquisition allowed the measurement of cerebral blood flow (CBF), apparent diffusion coefficient of water (ADCw), equilibrium magnetization (M0) and T1, and equilibrium magnetization and T1 under an off‐resonance partial saturation of the macromolecular pool (Msat and T1sat). Using these parameters, the apparent forward transfer rate of magnetization between the free water proton pool and the macromolecular proton pool, kfa, was calculated. Regions of interest (ROIs) were chosen using depressed areas in maps of the ADCw. T1 measurements in bovine serum albumin at 7T were not affected by the mobility of the macromolecular pool (P > 0.2), but magnetization transfer between free water and protein depended strongly on the mobility of the macromolecular pool (P < 0.001). For 6 hr after ictus, kfa uniformly and strongly decreased in the region of the infarct (P < 0.0001). Ratios (ischemic/non‐ischemic) of parameters M0, Msat, T1, and T1sat all uniformly and strongly increased in the infarct. The ratio T1/T1sat in the region of infarction showed that a progressive accumulation of free water in the region of interest was the major (>80%) contribution to the decrease in kfa. There also existed a small contribution due to changes at the water‐macromolecular interface, possibly due to proteolysis (P = 0.005). Magn Reson Med 41:696–705, 1999. © 1999 Wiley‐Liss, Inc.

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Spin-lattice relaxation times of bound water—Its determination and implications for tissue discrimination

Cited by 28 publications

References 19 publications

Human skin permittivity determined by millimeter wave reflection measurements

Human skin permittivity determined by millimeter wave reflection measurements

In Vivo Brain Water Determination by T₁ Measurements: Effect of Total Water Content, Hydration Fraction, and Field Strength

T1 and magnetization transfer at 7 Tesla in acute ischemic infarct in the rat

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Spin-lattice relaxation times of bound water—Its determination and implications for tissue discrimination

Cited by 28 publications

References 19 publications

Human skin permittivity determined by millimeter wave reflection measurements

Human skin permittivity determined by millimeter wave reflection measurements

In Vivo Brain Water Determination by T1 Measurements: Effect of Total Water Content, Hydration Fraction, and Field Strength

T1 and magnetization transfer at 7 Tesla in acute ischemic infarct in the rat

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In Vivo Brain Water Determination by T₁ Measurements: Effect of Total Water Content, Hydration Fraction, and Field Strength