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Chronological analysis of physiological T2* signal change in the cerebrum during breath holding
Author(s) -
Nakada Kazuyoshi,
Yoshida Daisuke,
Fukumoto Mitsutaka,
Yoshida Shoji
Publication year - 2001
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.1049
Subject(s) - hypercapnia , expiration , deoxygenated hemoglobin , cerebral blood flow , apnea , respiratory system , oxygenation , cerebrum , breathing , anesthesia , medicine , respiration , blood flow , cardiology , hemoglobin , anatomy , central nervous system
The purpose of this study was to examine which physiological factors affect cerebral T2* signal intensity (SI) during breath holding (BH) (apnea after inspiration and breathing after expiration) in normal volunteers. We examined SI changes caused by anoxic gas inhalation, by respiratory movements, and by BH. High‐speed echo planar images (EPI) showed changes in SI that could be divided into five phases. Reports indicate that SI changes induced by BH are due to the effects on the magnetic susceptibility of deoxygenated hemoglobin (deoxyhemoglobin (dHb)) and to hypercapnia, but these reports could not fully explain the observed five phases. In addition to deoxyhemoglobin susceptibility and hypercapnia, we found that respiratory movements play a third critical role in modifying SI by affecting blood flow into the region of interest (ROI), as judged from right carotid artery flow. Consequently, we propose that the physiological SI changes induced by BH are derived from blood oxygenation, hypercapnia, and respiratory movements. J. Magn. Reson. Imaging 2001;13:344–351. © 2001 Wiley‐Liss, Inc.