CONSTRUCTIONAL TOLERANCES OF SHIELDED GRADIENT-COIL SETS IN RELATION TO ARTIFACTS IN MRI AND ERRORS IN IN-VIVO MRS

被引:2
作者
LIU, Q [1 ]
HUGHES, DG [1 ]
ALLEN, PS [1 ]
机构
[1] UNIV ALBERTA,DEPT APPL SCI MED,EDMONTON,AB T6G 2J1,CANADA
来源
JOURNAL OF MAGNETIC RESONANCE SERIES B | 1995年 / 108卷 / 03期
关键词
D O I
10.1006/jmrb.1995.1125
中图分类号
O64 [物理化学(理论化学)、化学物理学]; O56 [分子物理学、原子物理学];
学科分类号
070203 ; 070304 ; 081704 ; 1406 ;
摘要
The potential of misregistration in the construction of shielded gradient sets for producing image artifacts or errors in localized spectroscopic measurements is evaluated in terms of a small axial relative displacement of the primary and shielding coils in a shielded, distributed current, cylindrical z-gradient set, An expression is derived for the eddy current induced in a surrounding coaxial cylinder, when the current in the gradient set is switched. The equation for the resulting eddy-current field generated along the z axis of the gradient set is then used to determine the maximum allowable relative displacement of the two-component coils. Numerical values are obtained for some typical imaging and spectroscopic protocols performed using representative animal-size or whole-body-size magnet systems. (C) 1995 academic press, Inc.
引用
收藏
页码:205 / 212
页数:8
相关论文
共 20 条
[1]   SPIN WARP NMR IMAGING AND APPLICATIONS TO HUMAN WHOLE-BODY IMAGING [J].
EDELSTEIN, WA ;
HUTCHISON, JMS ;
JOHNSON, G ;
REDPATH, T .
PHYSICS IN MEDICINE AND BIOLOGY, 1980, 25 (04) :751-756
[2]   RAPID NMR IMAGING OF DYNAMIC PROCESSES USING THE FLASH TECHNIQUE [J].
FRAHM, J ;
HAASE, A ;
MATTHAEI, D .
MAGNETIC RESONANCE IN MEDICINE, 1986, 3 (02) :321-327
[3]  
FRAHM J, 1987, J MAGN RESON, V72, P508
[4]   INTENSITY ARTIFACTS IN MRI CAUSED BY GRADIENT SWITCHING IN AN ANIMAL-SIZE NMR MAGNET [J].
HUGHES, DG ;
ROBERTSON, S ;
ALLEN, PS .
MAGNETIC RESONANCE IN MEDICINE, 1992, 25 (01) :167-179
[5]   ANALYTICAL METHOD FOR THE COMPENSATION OF EDDY-CURRENT EFFECTS INDUCED BY PULSED MAGNETIC-FIELD GRADIENTS IN NMR SYSTEMS [J].
JEHENSON, P ;
WESTPHAL, M ;
SCHUFF, N .
JOURNAL OF MAGNETIC RESONANCE, 1990, 90 (02) :264-278
[6]   INVIVO PROTON SPECTROSCOPY IN PRESENCE OF EDDY CURRENTS [J].
KLOSE, U .
MAGNETIC RESONANCE IN MEDICINE, 1990, 14 (01) :26-30
[7]   ABSOLUTE QUANTITATION OF WATER AND METABOLITES IN THE HUMAN BRAIN .2. METABOLITE CONCENTRATIONS [J].
KREIS, R ;
ERNST, T ;
ROSS, BD .
JOURNAL OF MAGNETIC RESONANCE SERIES B, 1993, 102 (01) :9-19
[8]   NMR FOURIER ZEUGMATOGRAPHY [J].
KUMAR, A ;
WELTI, D ;
ERNST, RR .
JOURNAL OF MAGNETIC RESONANCE, 1975, 18 (01) :69-83
[9]   QUANTITATIVE CHARACTERIZATION OF THE EDDY-CURRENT FIELDS IN A 40-CM BORE SUPERCONDUCTING MAGNET [J].
LIU, Q ;
HUGHES, DG ;
ALLEN, PS .
MAGNETIC RESONANCE IN MEDICINE, 1994, 31 (01) :73-76
[10]   BIOLOGICAL AND MEDICAL IMAGING BY NMR [J].
MANSFIELD, P ;
PYKETT, IL .
JOURNAL OF MAGNETIC RESONANCE, 1978, 29 (02) :355-373