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In vivo measurement of T* 2 and field inhomogeneity maps in the human heart at 1.5 T
Author(s) -
Reeder Scott B.,
Faranesh Anthony Z.,
Boxerman Jerrold L.,
McVeigh Elliot R.
Publication year - 1998
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910390617
Subject(s) - ventricle , nuclear magnetic resonance , apex (geometry) , distortion (music) , magnetic resonance imaging , physics , human heart , signal (programming language) , anatomy , nuclear medicine , medicine , radiology , amplifier , optoelectronics , cmos , computer science , programming language
Cardiac echo‐planar imaging suffers invariably from regions of severe distortion and T * 2 decay in the myocardium. The purpose of this work was to perform local measurements of T * 2 and field inhomogeneities in the myocardium and to identify the sources of focal signal loss and distortion. Field inhomogeneity maps and T * 2 were measured in five normal volunteers in short‐axis slices spanning from base to apex. It was found that T * 2 ranged from 26 ms (SD = 7 ms, n = 5) to 41 ms (SD = 11 ms, n = 5) over most of the heart, and peak‐to‐peak field inhomogeneity differences were 71 Hz (SD = 14 Hz, n = 5). In all hearts, regions of severe signal loss were consistently adjacent to the posterior vein of the left ventricle; T* 2 in these regions was 12 ms (SD = 2 ms, n = 5), and the difference in resonance frequency with the surrounding myocardium was 70‐100 Hz. These effects may be caused by increased magnetic susceptibility from deoxygenated blood in these veins.