THE EFFECTS OF RESTRICTED DIFFUSION IN NUCLEAR-MAGNETIC-RESONANCE MICROSCOPY

被引：12

作者：

HILLS, BP

WRIGHT, KM

BELTON, PS

机构：

[1] AFRC Institute of Food Research, Norwich Laboratory, Norwich, NR4 7UA, Colney Lane

来源：

MAGNETIC RESONANCE IMAGING | 1990年 / 8卷 / 06期

关键词：

Interfaces; Membranes; Microimaging; MRI; Multiple-echo imaging; NMR microscopy; Restricted diffusion;

D O I：

10.1016/0730-725X(90)90011-P

中图分类号：

R8 [特种医学]; R445 [影像诊断学];

学科分类号：

1002 ; 100207 ; 1009 ;

摘要：

A stochastic computer simulation is used to investigate the effects of restricted diffusion in NMR microscopy. It is shown that diffusion contributes to a loss of interfacial resolution through two main mechanisms. The first applies to spatial regions bound by impermeable interfaces and involves diffusive averaging of the frequency differences set up by the applied field gradients. This effect can be made arbitrarily small by increasing the magnitude of the field gradient. The second mechanism involves diffusion through permeable membranes or interfaces defining the sample morphology. This effect can, in principle, be reduced by multiple echo imaging with short pulse spacings. The possibility of imaging diffusive flow through a permeable interface is discussed. © 1990.

引用

页码：755 / 765

页数：11

共 11 条

[1]

Eccles, Callaghan, High resolution imaging. The NMR microscope, J. Magn. Reson., 68, (1986)

[2]

Aguayo, Blackband, Schoeniger, Mattingly, Hinterman, Nuclear magnetic resonance imaging of a single cell, Nature, 322, (1986)

[3]

Callaghan, Eccles, Sensitivity and resolution in NMR imaging, J. Magn. Reson., 71, (1987)

[4]

Callaghan, Eccles, Diffusion-limited resolution in nuclear magnetic resonance microscopy, J. Magn. Reson., 78, (1988)

[5]

Abragam, The Principles of Nuclear Medicine, (1961)

[6]

Robertson, Spin-echo decay of spins diffusing in a bounded region, Phys. Rev., 151, (1966)

[7]

Ernst, Methodology of magnetic resonance imaging, Quart. Rev. Biophys., 19, (1987)

[8]

Kaplan, Fraenkel, NMR of Chemically Exchanging Systems, (1980)

[9]

Belton, Hills, The effects of diffusive exchange in heterogeneous systems on N.M.R. line shapes and relaxation processes, Molecular Physics, 61, (1987)

[10]

Hills, Wright, Belton, N.M.R. studies of water proton relaxation in Sephadex bead suspensions, Molecular Physics, 67, (1989)

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