Comparison of calculated and experimental NMR spectral broadening for lung tissue
作者:
Rebecca A. Christman,
David C. Ailion,
Thomas A. Case,
Carl H. Durney,
Antonio G. Cutillo,
Sumie Shioya,
K. Craig Goodrich,
Alan H. Morris,
期刊:
Magnetic Resonance in Medicine
(WILEY Available online 1996)
卷期:
Volume 35,
issue 1
页码: 6-13
ISSN:0740-3194
年代: 1996
DOI:10.1002/mrm.1910350103
出版商: Wiley Subscription Services, Inc., A Wiley Company
关键词: susceptibility broadening;lineshape;lung
数据来源: WILEY
摘要:
AbstractNMR lineshapes were calculated for a model of lung, and NMR proton spectra were measured for individual voxels in an excised inflated rat lung. NMR lines for parenchymal lung regions containing alveoli, alveolar ducts, and capillaries were calculated using a computer simulation of the NMR signal from a three‐dimensional honeycomb‐like structure, a collection of modified Wigner‐Seitz cells. These cells were modified by rounding the comers and increasing the thickness of the boundaries to model various degrees of lung inflation and lung water. NMR lineshapes were also calculated for the central or nonparenchymal lung regions containing bronchi and large blood vessels. A comparison of theoretical lineshapes with those measured in individual voxels both in the parenchymal and in the central (largely nonparenchymal) regions in excised rat lungs at an inflation pressure of 30 cm of water shows excellent agreement These results indicate that the NMR lineshape reflects the underlying lung geometry. This research constitutes the first calculations and measurements of NMR lineshapes in lung. The appendix describes a new method for calculating the magnetic field inside a weakly diamagnetic material of arbitrary shape placed in an otherwise uniform external magnetic field. This new method does not require either solution of simultaneous equations or evaluation of integral expres
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