Detailing magnetic field strength dependence and segmental artifact distribution of myocardial effective transverse relaxation rate at 1.5, 3.0, and 7.0 T

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Item Type:	Article
Title:	Detailing magnetic field strength dependence and segmental artifact distribution of myocardial effective transverse relaxation rate at 1.5, 3.0, and 7.0 T
Creators Name:	Meloni, A., Hezel, F., Positano, V., Keilberg, P., Pepe, A., Lombardi, M. and Niendorf, T.
Abstract:	PURPOSE: Realizing the challenges and opportunities of effective transverse relaxation rate (R2 ) mapping at high and ultrahigh fields, this work examines magnetic field strength (B0 ) dependence and segmental artifact distribution of myocardial R2 at 1.5, 3.0, and 7.0 T. METHODS: Healthy subjects were considered. Three short-axis views of the left ventricle were examined. R2 * was calculated for 16 standard myocardial segments. Global and mid-septum R2 * were determined. For each segment, an artifactual factor was estimated as the deviation of segmental from global R2 * value. RESULTS: The global artifactual factor was significantly enlarged at 7.0 T versus 1.5 T (P = 0.010) but not versus 3.0 T. At 7.0 T, the most severe susceptibility artifacts were detected in the inferior lateral wall. The mid-septum showed minor artifactual factors at 7.0 T, similar to those at 1.5 and 3.0 T. Mean R2 * increased linearly with the field strength, with larger changes for global heart R2 * values. CONCLUSION: At 7.0 T, segmental heart R2 * analysis is challenging due to macroscopic susceptibility artifacts induced by the heart-lung interface and the posterior vein. Myocardial R2 * depends linearly on the magnetic field strength. The increased R2 * sensitivity at 7.0 T might offer means for susceptibility-weighted and oxygenation level-dependent MR imaging of the myocardium.
Keywords:	Ultrahigh Field MR, Magnetic Resonance Imaging, Cardiac Imaging, Cardiac R(2)*, High Field, Susceptibility Artifacts, 7.0 T, Myocardial Tissue Characterization
Source:	Magnetic Resonance in Medicine
ISSN:	0740-3194
Publisher:	Wiley
Volume:	71
Number:	6
Page Range:	2224-2230
Date:	June 2014
Official Publication:	https://doi.org/10.1002/mrm.24856
PubMed:	View item in PubMed

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