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ID 14028
Eprint ID
14028
FullText URL
Thumnail 106_359.pdf 728 KB
Title Alternative
The alteration of relaxation time and relaxivity by magnetic field strength
Author
Kitagawa, Takahiro
Abstract
Some parameters are altered by the magnetic field strength, and a different image is obtained with the same paremeter, because of the altered magnetic field strength. The contrast effect by contrast material for MRI (Gd-DTPA) differs with the magnetic field strength. We studied the T1 and T2 relaxation time of various solutions and relaxivity of Gd-DTPA with a low (0.2tesla) and high (1.5tesla) magnetic field machine, and considered the optimal sequence. T1 relaxation time is prolonged 20~40% at 1.5T compared with 0.2T. Using MnCI(2), the relaxivity of Gd-DTPA is 3.6~6.8mmo1(-1) sec(-1)1. Using albumin, the relaxivity is 5.8~12.1mmo1(-1) sec(-1)1. This difference is due to the difference in molecular size. Ti contrast, T2 contrast and signal intensity are weak with the low magnetic field machine. The signal intensity must be strengthened by changing some parameters (acquisitions, matrix, band width, etc.), and a shorter TR is suitable for T1 weighted images with a low magnetic field machine. For postcontrast T1 weighted images, shorter TR and shorter TE are useful to obtain a good contrast. More contrast material, and a longer TE is suitable for T2 weighted images wiht a low magnetic field machine.
Keywords
Magnetic Field Strength
Relaxation Time Relaxivity
Gd-DTPA
Pulse Sequence
Note
原著
Published Date
1994
Publication Title
岡山医学会雑誌
Publication Title Alternative
Journal of Okayama Medical Association
Volume
volume106
Issue
issue3-4
Publisher
岡山医学会
Publisher Alternative
Okayama Medical Association
Start Page
359
End Page
377
ISSN
0030-1558
NCID
AN00032489
Content Type
Journal Article
Official Url
https://www.jstage.jst.go.jp/article/joma1947/106/3-4/106_3-4_359/_article/-char/ja/
Related Url
http://www.okayama-u.ac.jp/user/oma/index.html
language
日本語
Copyright Holders
岡山医学会
File Version
publisher
Refereed
True
Eprints Journal Name
joma