Springer - Publisher Connector

Antonios G. Dougalis

Gillian A. C. Matthews

Birgit Liss

Mark A. Ungless

Ionic currents influencing spontaneous firing and pacemaker frequency in dopamine neurons of the ventrolateral periaqueductal gray and dorsal raphe nucleus (vlPAG/DRN): A voltage-clamp and computational modelling study

PCSK9 inhibition: the dawn of a new age in cholesterol lowering?

Ulrich Haisch

Priscilla Pani

Giacomo Polesello

Determining the CP nature of spin-0 mediators in associated production of dark matter and 


                                    
t

t
¯



$$ t\overline{t} $$
 pairs

Maarten van Iterson

null null

Erik W. van Zwet

Bastiaan T. Heijmans

Controlling bias and inflation in epigenome- and transcriptome-wide association studies using the empirical null distribution

A Graessl

W Renz

F Hezel

H Pfeiffer

W Hoffmann

P Kellman

T Niendorf

WORKSHOP PRESENTATION Open Access
Design, evaluation and application of a modular
32 channel transmit/receive surface coil array for
cardiac MRI at 7T
A Graessl1*, W Renz2, F Hezel1, H Pfeiffer3, W Hoffmann3, P Kellman4, T Niendorf1,5
From 16th Annual SCMR Scientific Sessions
San Francisco, CA, USA. 31 January - 3 February 2013
Background
Cardiac MR (CMR) at ultrahigh fields (≥7.0 T) is chal-
lenged by B1+ inhomogeneities and signal voids which
bear the potential to spoil the signal-to-noise (SNR) bene-
fits at 7.0 T. There is a trend towards an ever larger num-
ber of transmit and receive channels, to support multi-
dimensional B1+ shimming and parallel imaging. There-
fore this work proposes a modular, two dimensional
32-channel transmit and receive array using loop elements
and examines its efficacy for enhanced B1+ homogeneity
and improved parallel imaging performance.
Methods
The coil array consists of eight modules. Each module
comprises 4 independent transceiver loop elements with a
rectangular size of 6 cm x 6 cm each (Fig. 1a, b). Adjacent
elements share a common conductor with an adjustable
capacitor for decoupling of neighboring elements. Inter
module decoupling is suppressed by a distance of 3 cm
between neighboring loop structures. The MR experi-
ments were conducted on a 7 T scanner (Siemens Health-
care, Erlangen, Germany). The amplifier output was split
into 32 equal-intensity signals by means of home-built
power splitters. Phase adjustments were implemented by
phase-shifting coaxial . Electro-magnetic (EM) field and
SAR simulations were performed using CST Studio Suite
2011 (CST AG, Darmstadt, Germany) together with voxel
models from the Virtual Family. RF measurements and
Cardiac MR using single breath-hold 2D CINE FLASH
were done on three different subjects without subject-
specific tuning and matching.
Results
The modules are lightweight (m< 400 g) and conform to a
broad range of upper torso geometries. Reflection coeffi-
cients of -21± 7 dB were observed. Element coupling was
below -10 dB for all elements and subjects. Noise correla-
tion was 0.46 or well below for all elements and subjects
(Fig. 1c). SAR values derived from EM simulations were
well below the limits permitted by the IEC guidelines for
an average power of 30 W (Fig. 1d). The overall image
quality and the high spatial resolution of (1x1x4) mm3
enabled the visualization of subtle anatomic details
(Fig. 2a-d).
Conclusions
Our results demonstrate that the modular 32 channel coil
array supports the acquisition of rather uniform images of
1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine,
Berlin, Germany
Full list of author information is available at the end of the article
Figure 1 a) The coil placed on a mannequin. b) Basic scheme of the
coil design and positioning on the anterior chest. c) SAR distribution
derived from EMF simulations for transversal slice including the overall
SAR maximum. d) 32 x 32 noise correlation matrix obtained for the
proposed coil design.
Graessl et al. Journal of Cardiovascular Magnetic
Resonance 2013, 15(Suppl 1):W2
http://www.jcmr-online.com/content/15/S1/W2
© 2013 Graessl 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.
the heart at 7.0 T. Combining a large number of surface
coil elements yielded an excellent SNR and facilitated the
depiction of subtle anatomical cardiac details. The parallel
imaging performance enabled the acquisition of high reso-
lution images with satisfactory SNR within one breath-
hold (Fig. 2).
Author details
1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine,
Berlin, Germany. 2Siemens Healthcare, Erlangen, Germany. 3Physikalisch-
Technische Bundesanstalt (PTB), Berlin, Germany. 4Laboratory of Cardiac
Energetics, National Institute of Health/NHLBI, Bethesda, MD, USA.
5Experimental and Clinical Research Center (ECRC), Charité Campus Buch,
Humboldt-University, Berlin, Germany.
Published: 30 January 2013
doi:10.1186/1532-429X-15-S1-W2
Cite this article as: Graessl et al.: Design, evaluation and application of a
modular 32 channel transmit/receive surface coil array for cardiac MRI
at 7T. Journal of Cardiovascular Magnetic Resonance 2013 15(Suppl 1):W2.
Submit your next manuscript to BioMed Central
and take full advantage of: 
• Convenient online submission
• Thorough peer review
• No space constraints or color figure charges
• Immediate publication on acceptance
• Inclusion in PubMed, CAS, Scopus and Google Scholar
• Research which is freely available for redistribution
Submit your manuscript at 
www.biomedcentral.com/submit
Figure 2 a-d) Images of the heart derived from 2D CINE FLASH imaging using the proposed coil design (voxel size 1x1x4 mm3, TE/TR=2.65/5.6 ms,
BW=454 Hz): 4 chamber view, 3-chamber view, 2-chamber view, short axis view(R=2). e) GRAPPA g-factor map for short axis view and R=4.
Graessl et al. Journal of Cardiovascular Magnetic
Resonance 2013, 15(Suppl 1):W2
http://www.jcmr-online.com/content/15/S1/W2
Page 2 of 2


Design, evaluation and application of a modular 32 channel transmit/receive surface coil array for cardiac MRI at 7T

A prospective pilot study of home monitoring in adults with cystic fibrosis (HOME-CF): protocol for a randomised controlled trial

Improved recognition of ineffective chest compressions after a brief Crew Resource Management (CRM) training: a prospective, randomised simulation study

Vidya Nadig

Victoria Yeh

Vikas Gulani

Robert C Gilkeson

Nicole Seiberlich

POSTER PRESENTATION Open Access
Quantification of left ventricular ejection fraction
using through-time radial GRAPPA for real-time
imaging
Vidya Nadig1*, Victoria Yeh2, Vikas Gulani3,4, Robert C Gilkeson3, Nicole Seiberlich4
From 16th Annual SCMR Scientific Sessions
San Francisco, CA, USA. 31 January - 3 February 2013
Background
Cardiac MRI requires a steady cardiac rhythm for ECG-
gating, and multiple breath-holds to minimize respiratory
artifacts. By employing a non-Cartesian parallel imaging in
form of through-time radial GRAPPA [1], accelerated ima-
ging can be performed with temporal resolutions of < 50
ms, obviating the need for gating or breath-holding.
breath-holding. We tested the hypothesis that volumetric
measurements in the LV obtained with the real-time
method could replace traditional measurements.
Methods
A total of 31 subjects (23 patients, 8 volunteers) were
scanned on a 1.5T Avanto or 1.5T Espree scanner (Sie-
mens Medical Solutions, Erlangen, Germany) using a
combined spine and abdominal receiver array with 12 to
15 channels. The gold-standard cardiac functional exam-
ination was performed in a short-axis orientation with
ECG gating, requiring 12-16 breathholds with the fol-
lowing parameters: Cartesian bSSFP sequence, TR~31-
62 ms, in plane resolution = 1.4-2.6 mm2, slice thickness
= 6-8 mm, cardiac phases = 18-30. The real-time scans
(26 calibration frames per slice and accelerated acquisi-
tion) were performed immediately following the gold-
standard scan with no ECG gating or breath-holding:
radial bSSFP sequence, TR= 2.64 ms, resolution = 2.3
mm2, slice thickness = 6-8 mm. A data acceleration fac-
tor of R=8 (16 projections for 128 x 128 matrix) was
used such that the temporal resolution for real-time
imaging was 42.2 ms per image. Calibration data for
non-Cartesian GRAPPA reconstruction was acquired
without ECG gating or breath-holds. After data
collection and reconstruction, the blood volume in the
left ventricle was assessed to determine the ESV, EDV,
and EF for both methods.
Results
Bland-Altman analysis [2] was used to analyze the agree-
ment between the two methods. This showed that 30 of the
31 of the EF measurements using traditional breath-hold
imaging and the real-time free breathing method were
within the 95% limits of agreement. The mean difference in
LVEF between the two methods was -2% (breath-hold
minus real-time). All 31 measurements of EDV using both
methods were within 95% limits of agreement. The mean
difference in EDV between the two methods was -4ml. 30/
31 measurements of ESV using both methods were within
the 95% limits of agreement. The mean difference in ESV
between the two methods was 2 ml. The differences in EF,
EDV, and ESV are not clinically significant [3].
Conclusions
Our results show no significant statistical or clinical
difference between volumetric analysis determined using
standard breathhold cine imaging and through-time
radial GRAPPA. This indicates that standard method
can be replaced by the real-time imaging approach
which can be used even for patients with arrhythmia or
difficulty with breath-holding.
Funding
This work was funded by Case Western Reserve Univer-
sity/Cleveland Clinic CTSA UL1 RR024989, and NIH/
NIBIB R00EB011527.
1Cardiology, Metrohealth Campus of Case Western University, Cleveland, OH,
USA
Full list of author information is available at the end of the article
Nadig et al. Journal of Cardiovascular Magnetic
Resonance 2013, 15(Suppl 1):P45
http://www.jcmr-online.com/content/15/S1/P45
© 2013 Nadig 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.
Figure 1 Bland Altman plot of agreement of ejection fractions measured by standard breath-hold technique versus real-time free-breathing
technique.
Figure 2 Short axis images of the left ventricle obtained by standard breath-hold method and real-time radial GRAPPA.
Nadig et al. Journal of Cardiovascular Magnetic
Resonance 2013, 15(Suppl 1):P45
http://www.jcmr-online.com/content/15/S1/P45
Page 2 of 3
Author details
1Cardiology, Metrohealth Campus of Case Western University, Cleveland, OH,
USA. 2Case Western University School of Medicine, Cleveland, OH, USA.
3Radiology, University Hospitals of Cleveland, Cleveland, OH, USA.
4Biomedical Engineering, Case Western University School of Medicine,
Cleveland, OH, USA.
Published: 30 January 2013
References
1. Seiberlich N, et al:. MRM 2011, 65(2):492-505.
2. Altman DG, et al:. The Statistician 1983, 32(3):307-317.
3. Pattynama PM, et al: . Radiology 1993, 187:261-8.
doi:10.1186/1532-429X-15-S1-P45
Cite this article as: Nadig et al.: Quantification of left ventricular ejection
fraction using through-time radial GRAPPA for real-time imaging.
Journal of Cardiovascular Magnetic Resonance 2013 15(Suppl 1):P45.
Submit your next manuscript to BioMed Central
and take full advantage of: 
• Convenient online submission
• Thorough peer review
• No space constraints or color figure charges
• Immediate publication on acceptance
• Inclusion in PubMed, CAS, Scopus and Google Scholar
• Research which is freely available for redistribution
Submit your manuscript at 
www.biomedcentral.com/submit
Nadig et al. Journal of Cardiovascular Magnetic
Resonance 2013, 15(Suppl 1):P45
http://www.jcmr-online.com/content/15/S1/P45
Page 3 of 3


Quantification of left ventricular ejection fraction using through-time radial GRAPPA for real-time imaging

Autoinflammation in der Dermatologie

The role of biostimulants and bioeffectors as alleviators of abiotic stress in crop plants

Not a member yet