{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,10,24]],"date-time":"2023-10-24T05:13:43Z","timestamp":1698124423781},"reference-count":7,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2007,3,21]],"date-time":"2007-03-21T00:00:00Z","timestamp":1174435200000},"content-version":"vor","delay-in-days":5923,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Systems &amp; Computers in Japan"],"published-print":{"date-parts":[[1991,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The effect of the time\u2010variation of the static magnetic field in the permanent magnet MRI system on the image quality is studied, together with the method to eliminate the effect. The permanent magnet MRI system has a larger\u2010time\u2010variation of the static magnetic field than the superconducting magnet MRI system due to the temperature variation of the permanent magnet used to produce the static field. Thus, one of the important problems inherent to the permanent magnet MRI system is to examine the time\u2010variation of the static magnetic field intensity within the imaging time on the image quality. However, no detailed report has been made on this effect.<\/jats:p><jats:p>This paper shows that the effect of such variation on the image can be represented by the point\u2010spread function. Through the analysis of this point\u2010spread function, it is shown that the effect of the time\u2010variation of the static magnetic field is negligible in the ordinary imaging condition. Furthermore, a method is presented to cope with a time\u2010variation of the static magnetic field, which is produced by a sudden change of the hardware environment and is much larger than the variation in the usual imaging condition.<\/jats:p><jats:p>The variation of the static magnetic field in this method is measured during the imaging, and the effect of the variation is eliminated. The effectiveness of the method is verified based on the signal data obtained from the actual system.<\/jats:p>","DOI":"10.1002\/scj.4690220209","type":"journal-article","created":{"date-parts":[[2007,7,7]],"date-time":"2007-07-07T20:30:16Z","timestamp":1183840216000},"page":"76-84","source":"Crossref","is-referenced-by-count":0,"title":["Effects of main magnetic field time\u2010variation upon mr images in permanent magnet mri system"],"prefix":"10.1002","volume":"22","author":[{"given":"Tatsuo","family":"Nozokido","sequence":"first","affiliation":[]},{"given":"Takashi","family":"Onodera","sequence":"additional","affiliation":[]},{"given":"Etsuji","family":"Yamamoto","sequence":"additional","affiliation":[]}],"member":"311","published-online":{"date-parts":[[2007,3,21]]},"reference":[{"key":"e_1_2_1_2_2","article-title":"Development of MR imaging system using permanent magnet","volume":"89","author":"Sato S.","year":"1989","journal-title":"Tech. Rep. Magnetics, I.E.E., Japan"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1109\/PROC.1982.12447"},{"key":"e_1_2_1_4_2","unstructured":"T.MiyamotoandH.Sakurai.Application of Nd\u2010Fe\u2010B magnet to MRI. 58th Meeting Jap. Soc. Magnetics pp.97\u2013102(1989)."},{"key":"e_1_2_1_5_2","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910040506"},{"key":"e_1_2_1_6_2","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/31\/7\/002"},{"issue":"2","key":"e_1_2_1_7_2","first-page":"265","article-title":"Chemical shift imaging in permanent magnet MRI system","volume":"7","author":"Nozokido T.","year":"1989","journal-title":"Medical Imaging Technology"},{"key":"e_1_2_1_8_2","first-page":"13","volume-title":"Digital Image Processing","author":"Rosenfeld A.","year":"1978"}],"container-title":["Systems and Computers in Japan"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fscj.4690220209","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/scj.4690220209","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T07:15:41Z","timestamp":1698045341000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/scj.4690220209"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,1]]},"references-count":7,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1991,1]]}},"alternative-id":["10.1002\/scj.4690220209"],"URL":"https:\/\/doi.org\/10.1002\/scj.4690220209","archive":["Portico"],"relation":{},"ISSN":["0882-1666","1520-684X"],"issn-type":[{"value":"0882-1666","type":"print"},{"value":"1520-684X","type":"electronic"}],"subject":[],"published":{"date-parts":[[1991,1]]}}}