Effects of cell volume fraction changes on apparent diffusion in human cells

Anderson, Adam W.; Xie, Jingping; Pizzonia, John; Bronen, Richard A.; Spencer, Dennis D.; Gore, John C.

doi:10.1016/s0730-725x(00)00147-8

Cited by 164 publications

(148 citation statements)

References 21 publications

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“…In previous studies, Anderson et al (20,21) showed a drop in ADC with decreased extracellular volume, and a rise in ADC with increased extracellular volume in human erythrocytes and astrocytes. Our ex vivo results showing a further drop in ADC following centrifugation are due to the decrease in extracellular space with increased cellular packing, similar to that reported by Anderson et al (20,21).…”

Section: Discussionmentioning

confidence: 89%

Biological correlates of diffusivity in brain abscess

Mishra

Gupta

Saksena

et al. 2005

Magnetic Resonance in Med

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Restricted diffusion in brain abscess is assumed to be due to a combination of inflammatory cells, necrotic debris, viscosity, and macromolecules present in the pus. We performed diffusion-weighted imaging (DWI) on 41 patients with proven brain abscesses (36 pyogenic and five tuberculous), and correlated the apparent diffusion coefficient (ADC) from the abscess cavity with viable cell density, viscosity, and extracellular-protein content quantified from the pus. On the basis of the correlation between cell density and ADC in animal tumor models and human tumors in the literature, we assumed that the restricted ADC represents the cellular portion in the abscess cavity. We calculated restricted and unrestricted lesion volumes, and modeled cell density over the restricted area with viable cell density per mm 3 obtained from the pus. The mean restricted ADC in the cavity (0.65 ؎ 0.01 ؋ 10 -3 mm 2 /s) correlated inversely with restricted cell density in both the pyogenic (r ‫؍‬ -0.90, P ‫؍‬ <0.05) and tuberculous (0.60 ؎ 0.04 ؋ 10 -3 mm 2 /s, r ‫؍‬ -0.94, P ‫؍‬ <0.05) abscesses. We conclude that viable cell density is the main biological parameter responsible for restricted diffusion in brain abscess, and it is not influenced by the etiological agents responsible for its causation. Magn Reson Med 54:878 -885, 2005.

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Section: Discussionmentioning

confidence: 89%

Biological correlates of diffusivity in brain abscess

Mishra

Gupta

Saksena

et al. 2005

Magnetic Resonance in Med

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“…The magnetic resonance signal has been shown to be multiexponential, which indicates a multicompartmental origin. 1 H-MRI using transverse relaxativity focuses on the intrinsic property of water and its exchange between the different compartments as well as the binding capacity of the water molecule to subcellular structures (11). Most present studies have used a monoexponential transverse relaxativity analysis, although a multiexponential behavior has been described (24).…”

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confidence: 99%

“…These are probably related to both extra-and intracellular compartments, although the size of the extracellular volume seems to be the most important component. In vitro experiments have shown that ADC decreased when cells swell (1). A decreased ADC has also been related to cell swelling and decreased extracellular volume in the brain (2,9,31).…”

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confidence: 99%

Water exchange induced by unilateral exercise in active and inactive skeletal muscles

Nygren

Kaijser

2002

Journal of Applied Physiology

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Nygren, Anders T., and Lennart Kaijser. Water exchange induced by unilateral exercise in active and inactive skeletal muscles. J Appl Physiol 93: [1716][1717][1718][1719][1720][1721][1722] 2002. First published August 9, 2002; 10.1152/japplphysiol.01117. 2001.-Water exchange was evaluated in active (E-leg) and inactive skeletal muscles by using 1 H-magnetic resonance imaging. Six healthy subjects performed one-legged plantar flexion exercise at low and high workloads. Magnetic resonance imaging measured calf cross-sectional area (CSA), transverse relaxation time (T2), and apparent diffusion capacity (ADC) at rest and during recovery. After high workload, inactive muscle decreased CSA and T2 by 2.1% (P Ͻ 0.05) and 3.1% (P Ͻ 0.05), respectively, and left ADC unchanged. E-leg simultaneously increased CSA, T2, and ADC by 4.2% (P Ͻ 0.001), 15.5% (P Ͻ 0.05), and 12.5% (P Ͻ 0.001), respectively. In conclusion, ADC and T2 correlated highly with muscle volume, indicative of extravascular water displacement closely related to muscle activity and perfusion, which was presumably a combined effect of increased intracellular osmoles and hydrostatic forces as driving forces. A distinguishable muscle temperature release was initially detected in the E-leg after high workload, and the ensuing recovery of ADC and T2 indicated delayed interstitial restitution than restitution of the intracellular compartment. Furthermore, absorption of extravascular water was detected in inactive muscles at contralateral high-intensity exercise.diffusion; magnetic resonance imaging; tissue water; transverse relaxation time MAGNETIC RESONANCE IMAGING (MRI) can be applied on local skeletal muscle regions by analyzing variables pixel by pixel or within multiple local regions, including active as well as less active muscles (31). Therefore, simultaneous evaluation of water exchange in active and inactive muscles during dynamic exercise is valuable to elucidate the signal shift in muscle that is related to exercise and is beneficial to study how different MRI techniques that focus on water displacement relate.The physics of water exchange in the skeletal muscle is highly complex and multifactorial. The magnetic resonance signal has been shown to be multiexponential, which indicates a multicompartmental origin. 1 H-MRI using transverse relaxativity focuses on the intrinsic property of water and its exchange between the different compartments as well as the binding capacity of the water molecule to subcellular structures (11). Most present studies have used a monoexponential transverse relaxativity analysis, although a multiexponential behavior has been described (24). The monoexponential proton transverse relaxation time (T2) of skeletal muscle is known to increase by exercise (6,20). Increased intracellular water content (4, 18) and mechanisms related to aerobic capacity, e.g., net intramuscular accumulation of osmoles (22), are assumed to be the most important factors related to prolonged T2 with exercise. To what degree other factors such as H ϩ , p...

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“…MRI can visualize micromovements of water using the technology of diffusion-weighted imaging (dWI). 29) Cell membrane water permeability affects contrast in dWI, although it is not a major signal source for dWI under the usual clinical settings. It is possible to obtain absolute quantification by PET.…”

Section: Discussionmentioning

confidence: 99%

Molecular Imaging of Aquaglycero-Aquaporins: Its Potential for Cancer Characterization

Saito

Furukawa

Obata³

et al. 2013

Biological & Pharmaceutical Bulletin

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Aquaglycero-aquaporins (agAQPs) are one of the water channel proteins located in the cell membrane that transport not only water but also some small solutes such as glycerol. Since agAQPs are involved in cancer proliferation and malignancy, it might be possible to utilize them as new targets for cancer molecular imaging. In this study, we investigated whether agAQPs can be specifically targeted by using [14 C]-labeled glycerol ([ 14 C]glycerol), which passes through agAQPs. In the in vitro experiments, comparing the cancer cell lines with different expression levels of AQP3 and AQP9, major agAQPs known to be expressed in cancers, and examining the effect of their inhibitors on these cells, the expression of AQP3 and AQP9 in cell lines was shown to be closely related to [14 C]glycerol uptake. When [ 14 C]glycerol was injected into tumor-bearing mice, Spearman's rank coefficient analysis revealed that radioactivity levels in tumor and in plasma were mutually correlated only in tumors expressing agAQPs at a high level. These results indicate the possibility of using agAQPs as new targets to characterize cancer using radiolabeled glycerol as a molecular probe.

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Effects of cell volume fraction changes on apparent diffusion in human cells

Cited by 164 publications

References 21 publications

Biological correlates of diffusivity in brain abscess

Biological correlates of diffusivity in brain abscess

Water exchange induced by unilateral exercise in active and inactive skeletal muscles

Molecular Imaging of Aquaglycero-Aquaporins: Its Potential for Cancer Characterization

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