Abstract

Doc number: 63

Abstract

Background: Myocardial T1-mapping methods such as MOLLI use SSFP readout and are prone to frequency-dependent error in T1-measurement. A significant error in T1 may result at relatively small off-resonance frequencies that are well within the region without banding artifacts.

Methods: The sensitivity of T1-estimates based on the SSFP based MOLLI sequence to errors in center frequency are calculated by means of a Bloch simulation and validated by phantom measurements. Typical off-resonance errors following local cardiac shimming are determined by field mapping at both 1.5 and 3.0T. In vivo examples demonstrate the artifactual appearance of T1-maps in the presence of off-resonance variation.

Results: Off-resonance varied 61.8 ± 15.5 Hz (mean ± SD, n = 18) across the heart at 1.5T and 125.0 ± 40.6 Hz (mean ± SD, n = 18) at 3.0T. For T1 = 1000 ms, the variation in T1 due to off-resonance variation was approximately 20 ms at 62 Hz, and > 50 ms at 125 Hz.

Conclusions: Regional variations due to the inability to completely shim the B0-field variation around the heart appear as regional variation in T1, which is artifactual.

Details

Title
Influence of Off-resonance in myocardial T1-mapping using SSFP based MOLLI method
Author
Kellman, Peter; Herzka, Daniel A; Arai, Andrew E; Hansen, Michael Schacht
Pages
63
Publication year
2013
Publication date
2013
Publisher
BioMed Central
ISSN
10976647
e-ISSN
1532429X
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1186/1532-429X-15-63
ProQuest document ID
1419099621
Copyright
© 2013 Kellman et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.