A systematic evaluation of three different cardiac T2-mapping sequences at 1.5 and 3T in healthy volunteers

doi:10.1016/j.ejrad.2015.08.002

European Journal of Radiology

Volume 84, Issue 11, November 2015, Pages 2161-2170

https://doi.org/10.1016/j.ejrad.2015.08.002 Get rights and content

Highlights

•
Three different T2-mapping sequences are compared at 1.5 and 3T.
•
T2 values vary significantly between field strengths and MR sequences.
•
Segmental reference T2 values for each sequence at 1.5 and 3T are presented.
•
Phantom experiments reveal a T1 shine through effect for the T2prep sequence.

Abstract

Background

Previous studies showed that myocardial T2 relaxation times measured by cardiac T2-mapping vary significantly depending on sequence and field strength. Therefore, a systematic comparison of different T2-mapping sequences and the establishment of dedicated T2 reference values is mandatory for diagnostic decision-making.

Methods

Phantom experiments using gel probes with a range of different T1 and T2 times were performed on a clinical 1.5T and 3T scanner. In addition, 30 healthy volunteers were examined at 1.5 and 3T in immediate succession. In each examination, three different T2-mapping sequences were performed at three short-axis slices: Multi Echo Spin Echo (MESE), T2-prepared balanced SSFP (T2prep), and Gradient Spin Echo with and without fat saturation (GraSE_FS/GraSE). Segmented T2-Maps were generated according to the AHA 16-segment model and statistical analysis was performed.

Results

Significant intra-individual differences between mean T2 times were observed for all sequences. In general, T2prep resulted in lowest and GraSE in highest T2 times. A significant variation with field strength was observed for mean T2 in phantom as well as in vivo, with higher T2 values at 1.5T compared to 3T, regardless of the sequence used. Segmental T2 values for each sequence at 1.5 and 3T are presented.

Conclusions

Despite a careful selection of sequence parameters and volunteers, significant variations of the measured T2 values were observed between field strengths, MR sequences and myocardial segments. Therefore, we present segmental T2 values for each sequence at 1.5 and 3T with the inherent potential to serve as reference values for future studies.

Section snippets

Background

Myocardial oedema is a characteristic diagnostic finding in acute cardiac pathologies such as myocarditis or myocardial infarction. Cardiac T2-mapping has been suggested as a quantitative approach to oedema imaging, overcoming some of the known limitations of qualitative oedema assessment [1], [2], [3]. Accordingly, it may lead to a more objective image interpretation and allow for a more sensitive detection of either diffuse or even subtle changes in myocardial T2 relaxation times, especially

Phantom experiments

Phantom experiments were performed at 1.5T (Achieva 1.5T, Philips Medical Systems, Best, The Netherlands) and 3T (Ingenia 3T, Philips Medical Systems, Best, The Netherlands) using a commercially available cylindrical gel phantom (Eurospin test object TO5, Diagnostic Sonar, Livingston, UK) comprising 12 samples with T1 ranging from 313 ms to 1556 ms and T2 ranging from 50 ms to 160 ms, respectively. Mean T2 and standard deviations were measured at 1.5T and 3T in a homogeneous area of the sample

Phantom experiments

The detailed results of the phantom experiments are shown in Supplemental material 1. Phantom experiments showed that T2 relaxation times were generally higher at 1.5T compared to 3T for all sequences (p = 0.008 for MESE, p < 0.001 for T2prep and GraSE). At 1.5T, significantly higher T2 values were measured using T2prep and GraSE when compared to the MESE sequence (p < 0.001 for both). Conversely, GraSE and MESE resulted in nearly the same T2 relaxation times at 3T (p = 0.584), whereas T2 times

Discussion

To our best knowledge, this is the first study to systematically compare three different T2-mapping sequences at 1.5 and 3T in a phantom and in 30 healthy volunteers, revealing significant variations for derived T2 values depending on the sequence used. In addition, we observed significant differences of mean T2 times for different field strengths. These observations underline the need for dedicated reference values for each T2-mapping sequence at different field strengths. Hence, means and

Conclusions

Myocardial T2-mapping is technically feasible in healthy volunteers, although significant differences of derived mean T2 values can be found when applying different sequence designs and field strengths. Our observations make respective segmental reference values for different field strengths mandatory for diagnostic decision-making. Therefore, the present study offers first segmental reference values for three different cardiac T2-mapping sequences at 1.5 and 3T. The higher pixel-by-pixel

Conflicts of interest

Dr. Stehning and Dr. Schnackenburg are employees of Philips Research and Philips Healthcare, respectively. All other authors declare that they have no competing interests.

Acknowledgements

The authors wish to thank the technicians Denise Vossler and Claudia Müller for assisting in acquiring the CMR data.

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View full text

A systematic evaluation of three different cardiac T2-mapping sequences at 1.5 and 3T in healthy volunteers

Highlights

Abstract

Background

Methods

Results

Conclusions

Section snippets

Background

Phantom experiments

Phantom experiments

Discussion

Conclusions

Conflicts of interest

Acknowledgements

J. Cardiovasc. Magn. Reson.

J. Cardiovasc. Magn. Reson.

JACC Cardiovasc. Imaging

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J. Cardiovasc. Magn. Reson.

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Magn. Reson. Med.

Myocardial T2-mapping and velocity mapping: changes in regional left ventricular structure and function after heart transplantation

Magn. Reson. Med.

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J. Cardiovasc. Magn. Reson.

GRASE (gradient- and spin-echo) MR imaging: a new fast clinical imaging technique

Radiology

Effect of binge drinking on the heart as assessed by cardiac magnetic resonance imaging

J. Am. Med. Assoc.

Effect of aerobic capacity on the T(2) increase in exercised skeletal muscle

J. Appl. Physiol.

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J. Cardiovasc. Magn. Reson.

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Radiology