1H-MRS of the myocardium at 3T applying a 60-channel body array coil – initial experiences
Jürgen Machann1, Malte Niklas Bongers2, Andreas Fritsche3, Hans-Ulrich Häring3, Mike Notohamiprodjo4, Andreas Greiser5, Konstantin Nikolaou4, and Fritz Schick2

1Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, Institute for Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich, German Center for Diabetes Research (DZD), Tübingen, Germany, 2Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany, 3Department of Endocrinology and Diabetology, Angiology, Nephrology and Clinical Chemistry, Institute for Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich, German Center for Diabetes Research (DZD), Tübingen, Germany, 4Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany, 5Siemens Healthcare, Erlangen, Germany


1H-MRS is increasingly applied in many organs for non-invasive tissue characterization, e.g. for quantification of ectopic lipids. Spectroscopic examinations of the myocardium often suffer from limited spectral dispersion, thus limiting the metabolic information content. Applying a new 60-channel body-array receive coil, high quality spectra with superior dispersion as compared to previous setups are shown in this work. A single voxel PRESS technique was applied in 10 subjects. After higher-order shimming, linewidths of <20 Hz were obtained with high SNR in a clinically acceptable measuring time. High reproducibility and performance of the method may promote 1H-MRS applications in metabolic research and sports medicine.


1H-MRS of the myocardium is of increasing interest with manifold applications e.g. in metabolic research [1-3] or in sports medicine [4,5]. Acquisition of spectra is commonly performed applying ECG triggering and respiratory gating in order to avoid displacement of the volume of interest (VOI) and to obtain sufficient SNR. Despite this double-triggered acquisition scheme, the quality of spectra regarding spectral dispersion is typically rather limited – probably due to inherent magnetic field inhomogeneities (coil characteristics). Therefore signals of creatine (methyl-group, Cr3 at 3.05 ppm) and TMA (including choline and taurine at 3.2 ppm) often cannot be distinguished and separation of different lipid signals is aggravated. Aim of this preliminary study was to test the impact of a new 60-channel body-array receiver coil on spectral resolution and SNR in cardiac 1H-MRS in comparison to an 18-channel body-array coil in combination with a spine-array coil.


10 healthy untrained male subjects (age: 22-48 years, BMI<30kg/m²) were examined on a 3T whole body imager (Magnetom Skyra, Siemens Healthcare, Erlangen, Germany). Volunteers were lying in supine position on the posterior part of the new body-array coil and were covered by the anterior part (30 channels each) and spine-array coil + 18 channel body-array coil, respectively, for comparison. After morphological imaging including short-axis, four chamber-views and cine imaging, a VOI of 7 ml (20x10x35mm³) was placed in the intraventricular septum of the end-systolic cine images (see Figure 1a). Volume selective shimming was performed by automated, volume-selective higher-order shimming for optimal homogeneity using a shim volume of 4x4x4cm³. A PRESS-sequence with following measurement parameters was applied: TE/TR 36/≈2000 ms, BW 2000 Hz, 8 acq. without water suppression (WS), 32 acq. with WS. TA between 30 s and 40 s for spectra without WS and between 2:15 min and 2:40 min. for spectra with WS. Spectra of the single channels were summed without further corrections. Post processing included zero-filling to 4k, Fourier transformation and phase correction. Line width of the water signal was determined and spectral dispersion of the metabolites was rated by the resolution of Cr3 and TMA. SNR was calculated from raw data as ratio between the maximum signal of water divided by the standard deviation of noise from unsuppressed spectra.


A typical spectrum of a 25-year old male subject is shown in Figure 1b (without WS) and 1c (enlarged, with WS). High SNR and small linewidths enabled reliable separation of all metabolites of interest in all subjects. A splitting of the two lipid resonances – i.e. extramyocellular (EMCL) and intramyocellular lipids (IMCL) – can be seen in some volunteers which enables differentiation and quantification of these compartments. Line width of the water resonance ranged between 13 Hz and 17 Hz in the subjects and all spectra, were of high quality with excellent separation of Cr3 and TMA (at least to 50% of the maximum amplitude) and without any artifacts. SNR was clearly better (20-25%) and a smaller line width of the water signal (1-3 Hz) was obtained for the new coil compared to the 18 channel body-array coil in combination with the spine-array coil.


Cardiac MRS can be seen as the most challenging discipline for spectroscopic examinations in humans. A stable position of the VOI during data acquisition despite heart beat and breathing is a prerequisite for spectra of sufficient quality thus requiring ECG triggering and respiratory gating. Furthermore, HF transmission and signal reception – i.e. the applied coil – play a central role. The new 60-channel body array coil provides essential advantages compared to other commercially available coils with 16-32 channels and results in spectra with highest quality. All metabolites – including EMCL and IMCL – can be quantified reliably and offer a wealth of information about metabolism of the myocardium. It has to be mentioned that IMCL and EMCL could not be separated in all volunteers probably due to oblique muscle fiber orientation in the VOI under investigation and/or due to a dominant EMCL or IMCL resonance. Cross-sectional and interventional studies in the field of diabetes research and sports medicine are planned for the future.


Spectra of the myocardium could be assessed with excellent quality, enabling reliable quantification of all metabolites of interest. Regarding spectral dispersion, the properties are comparable to spectra recorded from the lower leg (e.g. soleus muscle), resulting in improved possibilities regarding metabolic analyses for future studies.


The study was supported in part by grants from the DeutscheForschungsgemeinschaft (KFO 114), the German Federal Ministry of Education and Research (BMBF) to the German Centre for Diabetes Research (DZD). The authors thank Siemens Healthcare (Erlangen, Germany) for continuous support.


[1] Ith M, Stettler C, Xu J, Boesch C, Kreis R. Cardiac lipid levels show diurnal changes and long-term variations in healthy human subjects. NMR Biomed. 2014;27(11):1285-1292.

[2] Krššák M, Winhofer Y, Göbl C et al. Insulin resistance is not associated with myocardial steatosis in women. Diabetologia 2011;54(7):1871-1878.

[3] Wei J, Nelson MD, Szczepaniak EW et al. Myocardial Steatosis as a Possible Mechanistic Link between Diastolic Dysfunction and Coronary Microvascular Dysfunction in Women. Am J Physiol Heart Circ Physiol 2015; doi: 10.1152/ajpheart.00612.2015

[4] Sai E, Shimada K, Yokoyama T et al. Association between myocardial triglyceride content and cardiac function in healthy subjects and endurance athletes. PLoS One 2013;8(4):e61604

[5] Bucher J, Krüsi M, Zueger T et al. The effect of a single 2 h bout of aerobic exercise on ectopic lipids in skeletal muscle, liver and the myocardium. Diabetologia 2014;57(5):1001-1005.


Figure 1: (a) position of the VOI in the septum and corresponding spectra: (b) without water suppression and (c) with water suppression - enlarged metabolites with excellent separation of the single resonances.

Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)