Cardiac T2-mapping using a fast gradient echo spin echo sequence - first in vitro and in vivo experience

Journal of Cardiovascular Magnetic Resonance

Technical Notes

Bettina Baeßler¹  David Maintz¹  Alexander C. Bunck¹  Frank Schaarschmidt²  Christian Stehning³  Bernhard Schnackenburg⁴ 

[1] Department of Radiology, University Hospital of Cologne, Kerpener Str. 62, D-50937, Cologne, Germany;Institute of Biostatistics, Faculty of Natural Sciences, Leibniz Universität Hannover, Hannover, Germany;Philips Research, Hamburg, Germany;Philips, Healthcare Germany, Hamburg, Germany;

关键词: Cardiovascular magnetic resonance;    T2-mapping;    Parametric imaging;   

DOI  :  10.1186/s12968-015-0177-2

 received in 2015-02-19, accepted in 2015-07-24,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe aim of this study was the evaluation of a fast Gradient Spin Echo Technique (GraSE) for cardiac T2-mapping, combining a robust estimation of T2 relaxation times with short acquisition times. The sequence was compared against two previously introduced T2-mapping techniques in a phantom and in vivo.MethodsPhantom experiments were performed at 1.5 T using a commercially available cylindrical gel phantom. Three different T2-mapping techniques were compared: a Multi Echo Spin Echo (MESE; serving as a reference), a T2-prepared balanced Steady State Free Precession (T2prep) and a Gradient Spin Echo sequence. For the subsequent in vivo study, 12 healthy volunteers were examined on a clinical 1.5 T scanner. The three T2-mapping sequences were performed at three short-axis slices. Global myocardial T2 relaxation times were calculated and statistical analysis was performed. For assessment of pixel-by-pixel homogeneity, the number of segments showing an inhomogeneous T2 value distribution, as defined by a pixel SD exceeding 20 % of the corresponding observed T2 time, was counted.ResultsPhantom experiments showed a greater difference of measured T2 values between T2prep and MESE than between GraSE and MESE, especially for species with low T1 values. Both, GraSE and T2prep resulted in an overestimation of T2 times compared to MESE. In vivo, significant differences between mean T2 times were observed. In general, T2prep resulted in lowest (52.4 ± 2.8 ms) and GraSE in highest T2 estimates (59.3 ± 4.0 ms). Analysis of pixel-by-pixel homogeneity revealed the least number of segments with inhomogeneous T2 distribution for GraSE-derived T2 maps.ConclusionsThe GraSE sequence is a fast and robust sequence, combining advantages of both MESE and T2prep techniques, which promises to enable improved clinical applicability of T2-mapping in the future. Our study revealed significant differences of derived mean T2 values when applying different sequence designs. Therefore, a systematic comparison of different cardiac T2-mapping sequences and the establishment of dedicated reference values should be the goal of future studies.

【 授权许可】

CC BY   
© Baeßler et al. 2015